Cover Page
Cover Page - USD ($) $ in Billions | 12 Months Ended | ||
Dec. 31, 2020 | Jan. 31, 2021 | Jun. 30, 2020 | |
Document Information [Line Items] | |||
Document Type | 10-K | ||
Document Annual Report | true | ||
Document Period End Date | Dec. 31, 2020 | ||
Current Fiscal Year End Date | --12-31 | ||
Document Transition Report | false | ||
Entity File Number | 1-3526 | ||
Entity Registrant Name | The Southern Company | ||
Entity Tax Identification Number | 58-0690070 | ||
Entity Incorporation, State or Country Code | DE | ||
Entity Address, Address Line One | 30 Ivan Allen Jr. Boulevard, N.W. | ||
Entity Address, City or Town | Atlanta | ||
Entity Address, State or Province | GA | ||
Entity Address, Postal Zip Code | 30308 | ||
City Area Code | 404 | ||
Local Phone Number | 506-5000 | ||
Entity Well-known Seasoned Issuer | Yes | ||
Entity Voluntary Filers | No | ||
Entity Current Reporting Status | Yes | ||
Entity Interactive Data Current | Yes | ||
Entity Filer Category | Large Accelerated Filer | ||
Entity Small Business | false | ||
Entity Emerging Growth Company | false | ||
ICFR Auditor Attestation Flag | true | ||
Entity Shell Company | false | ||
Entity Public Float | $ 54.8 | ||
Entity Common Stock, Shares Outstanding (in shares) | 1,056,609,660 | ||
Documents Incorporated by Reference | Documents incorporated by reference: specified portions of The Southern Company's Definitive Proxy Statement on Schedule 14A relating to the 2021 Annual Meeting of Stockholders are incorporated by reference into PART III. In addition, specified portions of Alabama Power Company's Definitive Proxy Statement on Schedule 14A relating to its 2021 Annual Meeting of Shareholders are incorporated by reference into PART III. Each of Georgia Power Company, Mississippi Power Company, Southern Power Company, and Southern Company Gas meets the conditions set forth in General Instructions I(1)(a) and (b) of Form 10-K and is therefore filing this Form 10-K with the reduced disclosure format specified in General Instructions I(2)(b), (c), and (d) of Form 10-K. This combined Form 10-K is separately filed by The Southern Company, Alabama Power Company, Georgia Power Company, Mississippi Power Company, Southern Power Company, and Southern Company Gas. Information contained herein relating to any individual registrant is filed by such registrant on its own behalf. Each registrant makes no representation as to information relating to the other registrants. | ||
Entity Central Index Key | 0000092122 | ||
Amendment Flag | false | ||
Document Fiscal Year Focus | 2020 | ||
Document Fiscal Period Focus | FY | ||
Common Stock, par value $5 per share | |||
Document Information [Line Items] | |||
Title of 12(b) Security | Common Stock, par value $5 per share | ||
Trading Symbol | SO | ||
Security Exchange Name | NYSE | ||
Series 2016A 5.25% Junior Subordinated Notes due 2076 | |||
Document Information [Line Items] | |||
Title of 12(b) Security | Series 2016A 5.25% Junior Subordinated Notes due 2076 | ||
Trading Symbol | SOJB | ||
Security Exchange Name | NYSE | ||
Series 2017B 5.25% Junior Subordinated Notes due 2077 | |||
Document Information [Line Items] | |||
Title of 12(b) Security | Series 2017B 5.25% Junior Subordinated Notes due 2077 | ||
Trading Symbol | SOJC | ||
Security Exchange Name | NYSE | ||
2019 Series A Corporate Units | |||
Document Information [Line Items] | |||
Title of 12(b) Security | 2019 Series A Corporate Units | ||
Trading Symbol | SOLN | ||
Security Exchange Name | NYSE | ||
Series 2020A 4.95% Junior Subordinated Notes due 2080 | |||
Document Information [Line Items] | |||
Title of 12(b) Security | Series 2020A 4.95% Junior Subordinated Notes due 2080 | ||
Trading Symbol | SOJD | ||
Security Exchange Name | NYSE | ||
Series 2020C 4.20% Junior Subordinated Notes due 2060 | |||
Document Information [Line Items] | |||
Title of 12(b) Security | Series 2020C 4.20% Junior Subordinated Notes due 2060 | ||
Trading Symbol | SOJE | ||
Security Exchange Name | NYSE | ||
Alabama Power | |||
Document Information [Line Items] | |||
Entity File Number | 1-3164 | ||
Entity Registrant Name | Alabama Power Company | ||
Entity Tax Identification Number | 63-0004250 | ||
Entity Incorporation, State or Country Code | AL | ||
Entity Address, Address Line One | 600 North 18th Street | ||
Entity Address, City or Town | Birmingham | ||
Entity Address, State or Province | AL | ||
Entity Address, Postal Zip Code | 35203 | ||
City Area Code | 205 | ||
Local Phone Number | 257-1000 | ||
Entity Well-known Seasoned Issuer | Yes | ||
Entity Voluntary Filers | No | ||
Entity Current Reporting Status | Yes | ||
Entity Interactive Data Current | Yes | ||
Entity Filer Category | Non-accelerated Filer | ||
Entity Small Business | false | ||
Entity Emerging Growth Company | false | ||
ICFR Auditor Attestation Flag | false | ||
Entity Shell Company | false | ||
Entity Common Stock, Shares Outstanding (in shares) | 30,537,500 | ||
Entity Central Index Key | 0000003153 | ||
Alabama Power | 5.00% Series Class A Preferred Stock | |||
Document Information [Line Items] | |||
Title of 12(b) Security | 5.00% Series Class A Preferred Stock | ||
Trading Symbol | ALP PR Q | ||
Security Exchange Name | NYSE | ||
Alabama Power | Preferred Stock, Cumulative, $100 Par Value, 4.20% Series | |||
Document Information [Line Items] | |||
Title of 12(g) Security | 4.20% Series | ||
Alabama Power | Preferred Stock, Cumulative, $100 Par Value, 4.52% Series | |||
Document Information [Line Items] | |||
Title of 12(g) Security | 4.52% Series | ||
Alabama Power | Preferred Stock, Cumulative, $100 Par Value, 4.60% Series | |||
Document Information [Line Items] | |||
Title of 12(g) Security | 4.60% Series | ||
Alabama Power | Preferred Stock, Cumulative, $100 Par Value, 4.64% Series | |||
Document Information [Line Items] | |||
Title of 12(g) Security | 4.64% Series | ||
Alabama Power | Preferred Stock, Cumulative, $100 Par Value, 4.72% Series | |||
Document Information [Line Items] | |||
Title of 12(g) Security | 4.72% Series | ||
Alabama Power | Preferred Stock, Cumulative, $100 Par Value, 4.92% Series | |||
Document Information [Line Items] | |||
Title of 12(g) Security | 4.92% Series | ||
Georgia Power | |||
Document Information [Line Items] | |||
Entity File Number | 1-6468 | ||
Entity Registrant Name | Georgia Power Company | ||
Entity Tax Identification Number | 58-0257110 | ||
Entity Incorporation, State or Country Code | GA | ||
Entity Address, Address Line One | 241 Ralph McGill Boulevard, N.E. | ||
Entity Address, City or Town | Atlanta | ||
Entity Address, State or Province | GA | ||
Entity Address, Postal Zip Code | 30308 | ||
City Area Code | 404 | ||
Local Phone Number | 506-6526 | ||
Entity Well-known Seasoned Issuer | Yes | ||
Entity Voluntary Filers | No | ||
Entity Current Reporting Status | Yes | ||
Entity Interactive Data Current | Yes | ||
Entity Filer Category | Non-accelerated Filer | ||
Entity Small Business | false | ||
Entity Emerging Growth Company | false | ||
ICFR Auditor Attestation Flag | false | ||
Entity Shell Company | false | ||
Entity Common Stock, Shares Outstanding (in shares) | 9,261,500 | ||
Entity Central Index Key | 0000041091 | ||
Georgia Power | Series 2017A 5.00% Junior Subordinated Notes due 2077 | |||
Document Information [Line Items] | |||
Title of 12(b) Security | Series 2017A 5.00% Junior Subordinated Notes due 2077 | ||
Trading Symbol | GPJA | ||
Security Exchange Name | NYSE | ||
Mississippi Power | |||
Document Information [Line Items] | |||
Entity File Number | 001-11229 | ||
Entity Registrant Name | Mississippi Power Company | ||
Entity Tax Identification Number | 64-0205820 | ||
Entity Incorporation, State or Country Code | MS | ||
Entity Address, Address Line One | 2992 West Beach Boulevard | ||
Entity Address, City or Town | Gulfport | ||
Entity Address, State or Province | MS | ||
Entity Address, Postal Zip Code | 39501 | ||
City Area Code | 228 | ||
Local Phone Number | 864-1211 | ||
Entity Well-known Seasoned Issuer | No | ||
Entity Voluntary Filers | No | ||
Entity Current Reporting Status | Yes | ||
Entity Interactive Data Current | Yes | ||
Entity Filer Category | Non-accelerated Filer | ||
Entity Small Business | false | ||
Entity Emerging Growth Company | false | ||
ICFR Auditor Attestation Flag | false | ||
Entity Shell Company | false | ||
Entity Common Stock, Shares Outstanding (in shares) | 1,121,000 | ||
Entity Central Index Key | 0000066904 | ||
Southern Power | |||
Document Information [Line Items] | |||
Entity File Number | 001-37803 | ||
Entity Registrant Name | Southern Power Company | ||
Entity Tax Identification Number | 58-2598670 | ||
Entity Incorporation, State or Country Code | DE | ||
Entity Address, Address Line One | 30 Ivan Allen Jr. Boulevard, N.W. | ||
Entity Address, City or Town | Atlanta | ||
Entity Address, State or Province | GA | ||
Entity Address, Postal Zip Code | 30308 | ||
City Area Code | 404 | ||
Local Phone Number | 506-5000 | ||
Entity Well-known Seasoned Issuer | No | ||
Entity Voluntary Filers | No | ||
Entity Current Reporting Status | Yes | ||
Entity Interactive Data Current | Yes | ||
Entity Filer Category | Non-accelerated Filer | ||
Entity Small Business | false | ||
Entity Emerging Growth Company | false | ||
ICFR Auditor Attestation Flag | false | ||
Entity Shell Company | false | ||
Entity Common Stock, Shares Outstanding (in shares) | 1,000 | ||
Entity Central Index Key | 0001160661 | ||
Southern Power | Series 2016A 1.000% Senior Notes due 2022 | |||
Document Information [Line Items] | |||
Title of 12(b) Security | Series 2016A 1.000% Senior Notes due 2022 | ||
Trading Symbol | SO/22B | ||
Security Exchange Name | NYSE | ||
Southern Power | Series 2016B 1.850% Senior Notes due 2026 | |||
Document Information [Line Items] | |||
Title of 12(b) Security | Series 2016B 1.850% Senior Notes due 2026 | ||
Trading Symbol | SO/26A | ||
Security Exchange Name | NYSE | ||
Southern Company Gas | |||
Document Information [Line Items] | |||
Entity File Number | 1-14174 | ||
Entity Registrant Name | Southern Company Gas | ||
Entity Tax Identification Number | 58-2210952 | ||
Entity Incorporation, State or Country Code | GA | ||
Entity Address, Address Line One | Ten Peachtree Place, N.E. | ||
Entity Address, City or Town | Atlanta | ||
Entity Address, State or Province | GA | ||
Entity Address, Postal Zip Code | 30309 | ||
City Area Code | 404 | ||
Local Phone Number | 584-4000 | ||
Entity Well-known Seasoned Issuer | No | ||
Entity Voluntary Filers | No | ||
Entity Current Reporting Status | Yes | ||
Entity Interactive Data Current | Yes | ||
Entity Filer Category | Non-accelerated Filer | ||
Entity Small Business | false | ||
Entity Emerging Growth Company | false | ||
ICFR Auditor Attestation Flag | false | ||
Entity Shell Company | false | ||
Entity Common Stock, Shares Outstanding (in shares) | 100 | ||
Entity Central Index Key | 0001004155 |
Consolidated Statements of Inco
Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Operating Revenues: | |||
Total operating revenues | $ 20,375 | $ 21,419 | $ 23,495 |
Operating Expenses: | |||
Other operations and maintenance | 5,413 | 5,624 | 5,926 |
Depreciation and amortization | 3,518 | 3,038 | 3,131 |
Taxes other than income taxes | 1,234 | 1,230 | 1,315 |
Estimated loss on Plant Vogtle Units 3 and 4 | 325 | 0 | 1,060 |
Impairment charges | 0 | 168 | 210 |
(Gain) loss on dispositions, net | (65) | (2,569) | (291) |
Total operating expenses | 15,490 | 13,683 | 19,304 |
Operating Income | 4,885 | 7,736 | 4,191 |
Other Income and (Expense): | |||
Allowance for equity funds used during construction | 149 | 128 | 138 |
Earnings from equity method investments | 153 | 162 | 148 |
Interest expense, net of amounts capitalized | (1,821) | (1,736) | (1,842) |
Impairment of leveraged leases | (206) | 0 | 0 |
Other income (expense), net | 336 | 252 | 114 |
Total other income and (expense) | (1,389) | (1,194) | (1,442) |
Earnings Before Income Taxes | 3,496 | 6,542 | 2,749 |
Income taxes (benefit) | 393 | 1,798 | 449 |
Net Income | 3,103 | 4,744 | 2,300 |
Dividends on preferred stock of subsidiaries | 15 | 15 | 16 |
Net income (loss) attributable to noncontrolling interests | (31) | (10) | 58 |
Consolidated Net Income | $ 3,119 | $ 4,739 | $ 2,226 |
Earnings per share — | |||
Basic (in dollars per share) | $ 2.95 | $ 4.53 | $ 2.18 |
Diluted (in dollars per share) | $ 2.93 | $ 4.50 | $ 2.17 |
Average number of shares of common stock outstanding — (in millions) | |||
Basic (in shares) | 1,058 | 1,046 | 1,020 |
Diluted (in shares) | 1,065 | 1,054 | 1,025 |
Retail electric revenues | |||
Operating Revenues: | |||
Total operating revenues | $ 13,643 | $ 14,084 | $ 15,222 |
Wholesale revenues | |||
Operating Revenues: | |||
Total operating revenues | 1,945 | 2,152 | 2,516 |
Other electric revenues | |||
Operating Revenues: | |||
Total operating revenues | 672 | 636 | 664 |
Natural gas | |||
Operating Revenues: | |||
Total operating revenues | 3,434 | 3,792 | 3,854 |
Operating Expenses: | |||
Cost of sales | 972 | 1,319 | 1,539 |
Other revenues | |||
Operating Revenues: | |||
Total operating revenues | 681 | 755 | 1,239 |
Operating Expenses: | |||
Cost of sales | 327 | 435 | 806 |
Fuel | |||
Operating Expenses: | |||
Cost of sales | 2,967 | 3,622 | 4,637 |
Purchased power | |||
Operating Expenses: | |||
Cost of sales | 799 | 816 | 971 |
Alabama Power | |||
Operating Revenues: | |||
Total operating revenues | 5,830 | 6,125 | 6,032 |
Operating Expenses: | |||
Other operations and maintenance | 1,619 | 1,821 | 1,669 |
Depreciation and amortization | 812 | 793 | 764 |
Taxes other than income taxes | 416 | 403 | 389 |
Total operating expenses | 4,136 | 4,532 | 4,555 |
Operating Income | 1,694 | 1,593 | 1,477 |
Other Income and (Expense): | |||
Allowance for equity funds used during construction | 46 | 52 | 62 |
Interest expense, net of amounts capitalized | (338) | (336) | (323) |
Other income (expense), net | 100 | 46 | 20 |
Total other income and (expense) | (192) | (238) | (241) |
Earnings Before Income Taxes | 1,502 | 1,355 | 1,236 |
Income taxes (benefit) | 337 | 270 | 291 |
Net Income | 1,165 | 1,085 | 945 |
Dividends on preferred stock of subsidiaries | 15 | 15 | 15 |
Consolidated Net Income | 1,150 | 1,070 | 930 |
Alabama Power | Retail electric revenues | |||
Operating Revenues: | |||
Total operating revenues | 5,213 | 5,501 | 5,367 |
Alabama Power | Wholesale revenues | |||
Operating Revenues: | |||
Total operating revenues | 269 | 258 | 279 |
Alabama Power | Wholesale revenues, affiliates | |||
Operating Revenues: | |||
Total operating revenues | 46 | 81 | 119 |
Alabama Power | Other revenues | |||
Operating Revenues: | |||
Total operating revenues | 302 | 285 | 267 |
Alabama Power | Fuel | |||
Operating Expenses: | |||
Cost of sales | 970 | 1,112 | 1,301 |
Alabama Power | Purchased power | |||
Operating Expenses: | |||
Cost of sales | 191 | 203 | 216 |
Alabama Power | Purchased power, affiliates | |||
Operating Expenses: | |||
Cost of sales | 128 | 200 | 216 |
Georgia Power | |||
Operating Revenues: | |||
Total operating revenues | 8,309 | 8,408 | 8,420 |
Operating Expenses: | |||
Other operations and maintenance | 1,953 | 1,972 | 1,860 |
Depreciation and amortization | 1,425 | 981 | 923 |
Taxes other than income taxes | 444 | 454 | 437 |
Estimated loss on Plant Vogtle Units 3 and 4 | 325 | 0 | 1,060 |
Total operating expenses | 6,337 | 5,947 | 7,131 |
Operating Income | 1,972 | 2,461 | 1,289 |
Other Income and (Expense): | |||
Allowance for equity funds used during construction | 91 | 68 | 69 |
Interest expense, net of amounts capitalized | (425) | (409) | (397) |
Other income (expense), net | 180 | 140 | 115 |
Total other income and (expense) | (245) | (269) | (282) |
Earnings Before Income Taxes | 1,727 | 2,192 | 1,007 |
Income taxes (benefit) | 152 | 472 | 214 |
Net Income | 1,575 | 1,720 | 793 |
Georgia Power | Retail electric revenues | |||
Operating Revenues: | |||
Total operating revenues | 7,609 | 7,707 | 7,752 |
Georgia Power | Wholesale revenues | |||
Operating Revenues: | |||
Total operating revenues | 115 | 140 | 187 |
Georgia Power | Other revenues | |||
Operating Revenues: | |||
Total operating revenues | 585 | 561 | 481 |
Georgia Power | Fuel | |||
Operating Expenses: | |||
Cost of sales | 1,141 | 1,444 | 1,698 |
Georgia Power | Purchased power | |||
Operating Expenses: | |||
Cost of sales | 540 | 521 | 430 |
Georgia Power | Purchased power, affiliates | |||
Operating Expenses: | |||
Cost of sales | 509 | 575 | 723 |
Mississippi Power | |||
Operating Revenues: | |||
Total operating revenues | 1,172 | 1,264 | 1,265 |
Operating Expenses: | |||
Other operations and maintenance | 284 | 307 | 350 |
Depreciation and amortization | 183 | 192 | 169 |
Taxes other than income taxes | 124 | 113 | 107 |
Total operating expenses | 963 | 1,039 | 1,072 |
Operating Income | 209 | 225 | 193 |
Other Income and (Expense): | |||
Interest expense, net of amounts capitalized | (60) | (69) | (76) |
Other income (expense), net | 17 | 13 | 17 |
Total other income and (expense) | (43) | (56) | (59) |
Earnings Before Income Taxes | 166 | 169 | 134 |
Income taxes (benefit) | 14 | 30 | (102) |
Net Income | 152 | 139 | 236 |
Dividends on preferred stock of subsidiaries | 0 | 0 | 1 |
Consolidated Net Income | 152 | 139 | 235 |
Mississippi Power | Retail electric revenues | |||
Operating Revenues: | |||
Total operating revenues | 821 | 877 | 889 |
Mississippi Power | Wholesale revenues | |||
Operating Revenues: | |||
Total operating revenues | 215 | 237 | 263 |
Mississippi Power | Wholesale revenues, affiliates | |||
Operating Revenues: | |||
Total operating revenues | 111 | 132 | 91 |
Mississippi Power | Other revenues | |||
Operating Revenues: | |||
Total operating revenues | 25 | 18 | 22 |
Mississippi Power | Fuel | |||
Operating Expenses: | |||
Cost of sales | 350 | 407 | 405 |
Mississippi Power | Purchased power | |||
Operating Expenses: | |||
Cost of sales | 22 | 20 | 41 |
Southern Power | |||
Operating Revenues: | |||
Total operating revenues | 1,733 | 1,938 | 2,205 |
Operating Expenses: | |||
Other operations and maintenance | 353 | 359 | 395 |
Depreciation and amortization | 494 | 479 | 493 |
Taxes other than income taxes | 39 | 40 | 46 |
Impairment charges | 0 | 3 | 156 |
(Gain) loss on dispositions, net | (39) | (23) | (2) |
Total operating expenses | 1,391 | 1,543 | 1,963 |
Operating Income | 342 | 395 | 242 |
Other Income and (Expense): | |||
Interest expense, net of amounts capitalized | (151) | (169) | (183) |
Other income (expense), net | 19 | 47 | 23 |
Total other income and (expense) | (132) | (122) | (160) |
Earnings Before Income Taxes | 210 | 273 | 82 |
Income taxes (benefit) | 3 | (56) | (164) |
Net Income | 207 | 329 | 246 |
Net income (loss) attributable to noncontrolling interests | (31) | (10) | 59 |
Consolidated Net Income | 238 | 339 | 187 |
Southern Power | Wholesale revenues | |||
Operating Revenues: | |||
Total operating revenues | 1,355 | 1,528 | 1,757 |
Southern Power | Wholesale revenues, affiliates | |||
Operating Revenues: | |||
Total operating revenues | 364 | 398 | 435 |
Southern Power | Other revenues | |||
Operating Revenues: | |||
Total operating revenues | 14 | 12 | 13 |
Southern Power | Fuel | |||
Operating Expenses: | |||
Cost of sales | 470 | 577 | 699 |
Southern Power | Purchased power | |||
Operating Expenses: | |||
Cost of sales | 74 | 108 | 176 |
Southern Company Gas | |||
Operating Revenues: | |||
Total operating revenues | 3,434 | 3,792 | 3,909 |
Operating Expenses: | |||
Other operations and maintenance | 966 | 888 | 981 |
Depreciation and amortization | 500 | 487 | 500 |
Taxes other than income taxes | 206 | 213 | 211 |
Impairment charges | 0 | 115 | 42 |
(Gain) loss on dispositions, net | (22) | 0 | (291) |
Total operating expenses | 2,622 | 3,022 | 2,994 |
Operating Income | 812 | 770 | 915 |
Other Income and (Expense): | |||
Earnings from equity method investments | 141 | 157 | 148 |
Interest expense, net of amounts capitalized | (231) | (232) | (228) |
Other income (expense), net | 41 | 20 | 1 |
Total other income and (expense) | (49) | (55) | (79) |
Earnings Before Income Taxes | 763 | 715 | 836 |
Income taxes (benefit) | 173 | 130 | 464 |
Net Income | 590 | 585 | 372 |
Consolidated Net Income | 590 | 585 | 372 |
Southern Company Gas | Natural gas | |||
Operating Revenues: | |||
Total operating revenues | 3,431 | 3,793 | 3,874 |
Operating Expenses: | |||
Cost of sales | 972 | 1,319 | 1,539 |
Southern Company Gas | Other revenues | |||
Operating Revenues: | |||
Total operating revenues | 0 | 0 | 55 |
Operating Expenses: | |||
Cost of sales | 0 | 0 | 12 |
Southern Company Gas | Alternative revenue programs | |||
Operating Revenues: | |||
Total operating revenues | $ 3 | $ (1) | $ (20) |
Consolidated Statements of In_2
Consolidated Statements of Income (Parenthetical) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Southern Company Gas | |||
Excise taxes collected | $ 107 | $ 117 | $ 114 |
Consolidated Statements of Comp
Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Net Income | $ 3,103 | $ 4,744 | $ 2,300 |
Qualifying hedges: | |||
Changes in fair value, net of tax | 10 | (115) | (47) |
Reclassification adjustment for amounts included in net income, net of tax | (40) | 57 | 72 |
Pension and other postretirement benefit plans: | |||
Benefit plan net gain (loss), net of tax | (55) | (64) | (5) |
Reclassification adjustment for amounts included in net income, net of tax | 10 | 4 | 6 |
Total other comprehensive income (loss) | (75) | (118) | 26 |
Dividends on preferred stock of subsidiaries | 15 | 15 | 16 |
Comprehensive income (loss) attributable to noncontrolling interests | (31) | (10) | 58 |
Comprehensive Income (Loss) Attributable to Parent | 3,044 | 4,621 | 2,252 |
Alabama Power | |||
Net Income | 1,165 | 1,085 | 945 |
Qualifying hedges: | |||
Reclassification adjustment for amounts included in net income, net of tax | 4 | 4 | 4 |
Pension and other postretirement benefit plans: | |||
Total other comprehensive income (loss) | 4 | 4 | 4 |
Dividends on preferred stock of subsidiaries | 15 | 15 | 15 |
Comprehensive Income (Loss) Attributable to Parent | 1,169 | 1,089 | 949 |
Georgia Power | |||
Net Income | 1,575 | 1,720 | 793 |
Qualifying hedges: | |||
Changes in fair value, net of tax | (2) | (44) | 0 |
Reclassification adjustment for amounts included in net income, net of tax | 6 | 2 | 3 |
Pension and other postretirement benefit plans: | |||
Total other comprehensive income (loss) | 4 | (42) | 3 |
Comprehensive Income (Loss) Attributable to Parent | 1,579 | 1,678 | 796 |
Mississippi Power | |||
Net Income | 152 | 139 | 236 |
Qualifying hedges: | |||
Changes in fair value, net of tax | 0 | 0 | (1) |
Reclassification adjustment for amounts included in net income, net of tax | 1 | 1 | 1 |
Pension and other postretirement benefit plans: | |||
Total other comprehensive income (loss) | 1 | 1 | 0 |
Dividends on preferred stock of subsidiaries | 0 | 0 | 1 |
Comprehensive Income (Loss) Attributable to Parent | 153 | 140 | 236 |
Southern Power | |||
Net Income | 207 | 329 | 246 |
Qualifying hedges: | |||
Changes in fair value, net of tax | 33 | (66) | (51) |
Reclassification adjustment for amounts included in net income, net of tax | (65) | 41 | 58 |
Pension and other postretirement benefit plans: | |||
Benefit plan net gain (loss), net of tax | (12) | (17) | 5 |
Reclassification adjustment for amounts included in net income, net of tax | 2 | 0 | 2 |
Total other comprehensive income (loss) | (42) | (42) | 14 |
Comprehensive income (loss) attributable to noncontrolling interests | (31) | (10) | 59 |
Comprehensive Income (Loss) Attributable to Parent | 196 | 297 | 201 |
Southern Company Gas | |||
Net Income | 590 | 585 | 372 |
Qualifying hedges: | |||
Changes in fair value, net of tax | (21) | (5) | 5 |
Reclassification adjustment for amounts included in net income, net of tax | 7 | 2 | (1) |
Pension and other postretirement benefit plans: | |||
Benefit plan net gain (loss), net of tax | (15) | (16) | 0 |
Reclassification adjustment for amounts included in net income, net of tax | 0 | 0 | (2) |
Total other comprehensive income (loss) | (29) | (19) | 2 |
Comprehensive Income (Loss) Attributable to Parent | $ 561 | $ 566 | $ 374 |
Consolidated Statements of Co_2
Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Qualifying hedges, change in fair value, tax | $ 3 | $ (39) | $ (16) |
Qualifying hedges, reclassification adjustment, tax | (13) | 19 | (24) |
Pension and other postretirement benefit plans, gain (loss), tax | (17) | (31) | (2) |
Reclassification adjustment for amounts included in net income, tax | 3 | 1 | 5 |
Alabama Power | |||
Qualifying hedges, reclassification adjustment, tax | 2 | 2 | 2 |
Georgia Power | |||
Qualifying hedges, change in fair value, tax | (1) | (15) | 0 |
Qualifying hedges, reclassification adjustment, tax | 2 | 1 | 1 |
Mississippi Power | |||
Qualifying hedges, change in fair value, tax | 0 | 0 | (1) |
Qualifying hedges, reclassification adjustment, tax | 0 | 0 | 0 |
Southern Power | |||
Qualifying hedges, change in fair value, tax | 12 | (22) | (17) |
Qualifying hedges, reclassification adjustment, tax | (22) | 14 | 19 |
Pension and other postretirement benefit plans, gain (loss), tax | (4) | (6) | 2 |
Reclassification adjustment for amounts included in net income, tax | 1 | 0 | 0 |
Southern Company Gas | |||
Qualifying hedges, change in fair value, tax | (8) | (2) | 2 |
Qualifying hedges, reclassification adjustment, tax | 3 | 0 | (1) |
Pension and other postretirement benefit plans, gain (loss), tax | (3) | (14) | 0 |
Reclassification adjustment for amounts included in net income, tax | $ 0 | $ 0 | $ 3 |
Consolidated Statements of Cash
Consolidated Statements of Cash Flows - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Operating Activities: | |||
Consolidated net income | $ 3,103,000 | $ 4,744,000 | $ 2,300,000 |
Adjustments to reconcile consolidated net income to net cash provided from operating activities — | |||
Depreciation and amortization, total | 3,905,000 | 3,331,000 | 3,549,000 |
Deferred income taxes | (241,000) | 611,000 | 89,000 |
Utilization of federal investment tax credits | 341,000 | 757,000 | 5,000 |
Amortization of investment tax credits | (84,000) | (181,000) | (87,000) |
Allowance for equity funds used during construction | (149,000) | (128,000) | (138,000) |
Pension, postretirement, and other employee benefits | (259,000) | (204,000) | (103,000) |
Pension and postretirement funding | (2,000) | (1,136,000) | (4,000) |
Settlement of asset retirement obligations | (442,000) | (328,000) | (244,000) |
Storm damage accruals | 325,000 | 168,000 | 74,000 |
Stock based compensation expense | 113,000 | 107,000 | 125,000 |
Estimated loss on Plant Vogtle Units 3 and 4 | 325,000 | 0 | 1,060,000 |
Impairment charges | 206,000 | 168,000 | 210,000 |
Impairment charges | 0 | 168,000 | 210,000 |
(Gain) loss on dispositions, net | (66,000) | (2,588,000) | (301,000) |
Other, net | (74,000) | 115,000 | 47,000 |
Changes in certain current assets and liabilities — | |||
-Receivables | (222,000) | 630,000 | (426,000) |
-Fossil fuel for generation | (29,000) | (120,000) | 123,000 |
-Materials and supplies | (157,000) | (17,000) | (176,000) |
-Other current assets | (132,000) | 132,000 | 98,000 |
-Accounts payable | (27,000) | (693,000) | 291,000 |
-Accrued taxes | 242,000 | 117,000 | 267,000 |
-Retail fuel cost over recovery | 96,000 | 62,000 | 36,000 |
-Customer refunds | (236,000) | 126,000 | 67,000 |
-Other current liabilities | 76,000 | (73,000) | (4,000) |
Net cash provided from operating activities | 6,696,000 | 5,781,000 | 6,945,000 |
Investing Activities: | |||
Business acquisitions, net of cash acquired | (81,000) | (50,000) | (65,000) |
Property additions | (7,441,000) | (7,555,000) | (8,001,000) |
Nuclear decommissioning trust fund purchases | (877,000) | (888,000) | (1,117,000) |
Nuclear decommissioning trust fund sales | 871,000 | 882,000 | 1,111,000 |
Proceeds from dispositions and asset sales | 1,049,000 | 5,122,000 | 2,956,000 |
Cost of removal, net of salvage | (361,000) | (393,000) | (388,000) |
Change in construction payables, net | 37,000 | (169,000) | 50,000 |
Investments in unconsolidated subsidiaries | (80,000) | (148,000) | (114,000) |
Payments pursuant to LTSAs | (211,000) | (234,000) | (186,000) |
Other investing activities | 64,000 | 41,000 | (6,000) |
Net cash used for investing activities | (7,030,000) | (3,392,000) | (5,760,000) |
Financing Activities: | |||
Increase (decrease) in notes payable, net | 640,000 | ||
Increase (decrease) in notes payable, net | (1,096,000) | (774,000) | |
Proceeds — | |||
Long-term debt | 8,047,000 | 5,220,000 | 2,478,000 |
Common stock | 74,000 | 844,000 | 1,090,000 |
Short-term borrowings | 615,000 | 350,000 | 3,150,000 |
Redemptions and repurchases — | |||
Long-term debt | (4,458,000) | (4,347,000) | (5,533,000) |
Preferred and preference stock | 0 | 0 | (33,000) |
Short-term borrowings | (840,000) | (1,850,000) | (1,900,000) |
Distributions to noncontrolling interests | (271,000) | (256,000) | (153,000) |
Capital contributions from noncontrolling interests | 363,000 | 196,000 | 2,551,000 |
Payment of common stock dividends | (2,685,000) | (2,570,000) | (2,425,000) |
Other financing activities | (325,000) | (157,000) | (264,000) |
Net cash used for financing activities | (576,000) | (1,930,000) | (1,813,000) |
Net Change in Cash, Cash Equivalents, and Restricted Cash | (910,000) | 459,000 | (628,000) |
Cash, Cash Equivalents, and Restricted Cash at Beginning of Year | 1,978,000 | 1,519,000 | 2,147,000 |
Cash, Cash Equivalents, and Restricted Cash at End of Year | 1,068,000 | 1,978,000 | 1,519,000 |
Supplemental Cash Flow Information: | |||
Interest, net of amounts capitalized | 1,683,000 | 1,651,000 | 1,794,000 |
Income taxes (net of refunds) | 64,000 | 276,000 | 172,000 |
Noncash transactions — | |||
Accrued property additions at year-end | 989,000 | 932,000 | 1,103,000 |
Alabama Power | |||
Operating Activities: | |||
Consolidated net income | 1,165,000 | 1,085,000 | 945,000 |
Adjustments to reconcile consolidated net income to net cash provided from operating activities — | |||
Depreciation and amortization, total | 963,000 | 951,000 | 917,000 |
Deferred income taxes | 78,000 | 197,000 | 174,000 |
Allowance for equity funds used during construction | (46,000) | (52,000) | (62,000) |
Pension and postretirement funding | (2,000) | (362,000) | (4,000) |
Settlement of asset retirement obligations | (219,000) | (127,000) | (55,000) |
Natural disaster reserve accruals | 112,000 | 138,000 | 16,000 |
Other deferred charges – affiliated | 0 | (42,000) | 0 |
Other, net | (38,000) | (91,000) | (17,000) |
Changes in certain current assets and liabilities — | |||
-Receivables | (49,000) | 9,000 | (149,000) |
-Materials and supplies | (47,000) | 23,000 | (82,000) |
-Other current assets | (66,000) | (89,000) | 28,000 |
-Accounts payable | (90,000) | (41,000) | 24,000 |
-Accrued taxes | 84,000 | 49,000 | 10,000 |
-Retail fuel cost over recovery | (31,000) | 47,000 | 0 |
-Customer refunds | (12,000) | 30,000 | 114,000 |
-Other current liabilities | (28,000) | 68,000 | 14,000 |
-Accrued compensation | (32,000) | (14,000) | 8,000 |
Net cash provided from operating activities | 1,742,000 | 1,779,000 | 1,881,000 |
Investing Activities: | |||
Property additions | (1,970,000) | (1,757,000) | (2,158,000) |
Nuclear decommissioning trust fund purchases | (268,000) | (261,000) | (279,000) |
Nuclear decommissioning trust fund sales | 267,000 | 260,000 | 278,000 |
Cost of removal, net of salvage | (98,000) | (103,000) | (130,000) |
Change in construction payables, net | (34,000) | (71,000) | 26,000 |
Other investing activities | (19,000) | (31,000) | (26,000) |
Net cash used for investing activities | (2,122,000) | (1,963,000) | (2,289,000) |
Proceeds — | |||
Senior notes | 600,000 | 600,000 | 500,000 |
Pollution control revenue bonds | 87,000 | 0 | 120,000 |
Capital contributions from parent company | 653,000 | 1,240,000 | 511,000 |
Redemptions and repurchases — | |||
Senior notes | (250,000) | (200,000) | 0 |
Pollution control revenue bonds | (87,000) | 0 | (120,000) |
Payment of common stock dividends | (957,000) | (844,000) | (801,000) |
Other financing activities | (30,000) | (31,000) | (33,000) |
Net cash used for financing activities | 16,000 | 765,000 | 177,000 |
Net Change in Cash, Cash Equivalents, and Restricted Cash | (364,000) | 581,000 | (231,000) |
Cash, Cash Equivalents, and Restricted Cash at Beginning of Year | 894,000 | 313,000 | 544,000 |
Cash, Cash Equivalents, and Restricted Cash at End of Year | 530,000 | 894,000 | 313,000 |
Supplemental Cash Flow Information: | |||
Interest, net of amounts capitalized | 321,000 | 311,000 | 284,000 |
Income taxes (net of refunds) | 187,000 | 26,000 | 106,000 |
Noncash transactions — | |||
Accrued property additions at year-end | 166,000 | 200,000 | 272,000 |
Georgia Power | |||
Operating Activities: | |||
Consolidated net income | 1,575,000 | 1,720,000 | 793,000 |
Adjustments to reconcile consolidated net income to net cash provided from operating activities — | |||
Depreciation and amortization, total | 1,607,000 | 1,193,000 | 1,142,000 |
Deferred income taxes | (273,000) | 179,000 | (260,000) |
Allowance for equity funds used during construction | (91,000) | (68,000) | (69,000) |
Pension, postretirement, and other employee benefits | (137,000) | (146,000) | (75,000) |
Pension and postretirement funding | 0 | (200,000) | 0 |
Settlement of asset retirement obligations | (185,000) | (151,000) | (116,000) |
Retail fuel cost over recovery – long-term | (73,000) | 73,000 | 0 |
Storm damage accruals | 213,000 | 30,000 | 30,000 |
Other deferred charges – affiliated | 0 | (108,000) | 0 |
Estimated loss on Plant Vogtle Units 3 and 4 | 325,000 | 0 | 1,060,000 |
Other, net | 14,000 | 50,000 | 18,000 |
Changes in certain current assets and liabilities — | |||
-Receivables | (114,000) | 177,000 | 8,000 |
-Fossil fuel for generation | (6,000) | (41,000) | 83,000 |
-Materials and supplies | (91,000) | (4,000) | (19,000) |
-Other current assets | (48,000) | (15,000) | (24,000) |
-Accounts payable | 59,000 | (92,000) | 95,000 |
-Accrued taxes | 55,000 | 58,000 | 58,000 |
-Retail fuel cost over recovery | 113,000 | 0 | 0 |
-Customer refunds | (223,000) | 116,000 | (69,000) |
-Other current liabilities | 64,000 | 34,000 | (38,000) |
-Prepaid income taxes | 0 | 102,000 | 152,000 |
Net cash provided from operating activities | 2,784,000 | 2,907,000 | 2,769,000 |
Investing Activities: | |||
Property additions | (3,445,000) | (3,510,000) | (3,116,000) |
Nuclear decommissioning trust fund purchases | (609,000) | (628,000) | (839,000) |
Nuclear decommissioning trust fund sales | 604,000 | 622,000 | 833,000 |
Cost of removal, net of salvage | (143,000) | (186,000) | (107,000) |
Payments pursuant to LTSAs | (86,000) | (81,000) | (54,000) |
Change in construction payables, net of joint owner portion | 16,000 | (122,000) | 68,000 |
Proceeds from dispositions and asset sales | 153,000 | 14,000 | 138,000 |
Other investing activities | 7,000 | 6,000 | (32,000) |
Net cash used for investing activities | (3,503,000) | (3,885,000) | (3,109,000) |
Financing Activities: | |||
Increase (decrease) in notes payable, net | 294,000 | ||
Increase (decrease) in notes payable, net | (55,000) | (179,000) | |
Proceeds — | |||
FFB loan | 848,000 | 1,218,000 | 0 |
Short-term borrowings | 250,000 | 250,000 | 0 |
Senior notes | 1,500,000 | 750,000 | 0 |
Pollution control revenue bonds | 53,000 | 584,000 | 108,000 |
Capital contributions from parent company | 1,392,000 | 634,000 | 2,985,000 |
Redemptions and repurchases — | |||
FFB loan | (73,000) | 0 | 0 |
Short-term borrowings | (375,000) | 0 | (150,000) |
Senior notes | (950,000) | (500,000) | (1,500,000) |
Pollution control revenue bonds | (336,000) | (223,000) | (469,000) |
Other long-term debt | 0 | 0 | (100,000) |
Payment of common stock dividends | (1,542,000) | (1,576,000) | (1,396,000) |
Premiums on redemption and repurchases of senior notes | 0 | 0 | (152,000) |
Other financing activities | (36,000) | (40,000) | (20,000) |
Net cash used for financing activities | 676,000 | 918,000 | (400,000) |
Net Change in Cash, Cash Equivalents, and Restricted Cash | (43,000) | (60,000) | (740,000) |
Cash, Cash Equivalents, and Restricted Cash at Beginning of Year | 52,000 | 112,000 | 852,000 |
Cash, Cash Equivalents, and Restricted Cash at End of Year | 9,000 | 52,000 | 112,000 |
Supplemental Cash Flow Information: | |||
Interest, net of amounts capitalized | 380,000 | 373,000 | 408,000 |
Income taxes (net of refunds) | 373,000 | 110,000 | 300,000 |
Noncash transactions — | |||
Accrued property additions at year-end | 553,000 | 560,000 | 683,000 |
Mississippi Power | |||
Operating Activities: | |||
Consolidated net income | 152,000 | 139,000 | 236,000 |
Adjustments to reconcile consolidated net income to net cash provided from operating activities — | |||
Depreciation and amortization, total | 191,000 | 197,000 | 177,000 |
Deferred income taxes | (4,000) | 37,000 | 475,000 |
Pension and postretirement funding | 0 | (54,000) | 0 |
Settlement of asset retirement obligations | (22,000) | (35,000) | (35,000) |
Other, net | (1,000) | 35,000 | 51,000 |
Changes in certain current assets and liabilities — | |||
-Receivables | (7,000) | 6,000 | (19,000) |
-Other current assets | (28,000) | (8,000) | (10,000) |
-Accounts payable | 20,000 | 3,000 | 15,000 |
-Accrued taxes | 10,000 | 11,000 | (46,000) |
-Other current liabilities | (15,000) | (20,000) | (42,000) |
-Prepaid income taxes | (3,000) | 12,000 | (12,000) |
-Over recovered regulatory clause revenues | 5,000 | 16,000 | 14,000 |
Net cash provided from operating activities | 298,000 | 339,000 | 804,000 |
Investing Activities: | |||
Property additions | (274,000) | (202,000) | (188,000) |
Payments pursuant to LTSAs | (28,000) | (23,000) | (29,000) |
Other investing activities | (21,000) | (38,000) | (15,000) |
Net cash used for investing activities | (323,000) | (263,000) | (232,000) |
Financing Activities: | |||
Increase (decrease) in notes payable, net | 25,000 | ||
Increase (decrease) in notes payable, net | 0 | (4,000) | |
Proceeds — | |||
Short-term borrowings | 40,000 | 0 | 300,000 |
Senior notes | 0 | 0 | 600,000 |
Pollution control revenue bonds | 34,000 | 43,000 | 0 |
Other long-term debt | 100,000 | 0 | 0 |
Capital contributions from parent company | 85,000 | 51,000 | 15,000 |
Redemptions and repurchases — | |||
Preferred and preference stock | 0 | 0 | (33,000) |
Short-term borrowings | (40,000) | 0 | (300,000) |
Senior notes | (275,000) | (25,000) | (155,000) |
Pollution control revenue bonds | (41,000) | 0 | (43,000) |
Other long-term debt | 0 | 0 | (900,000) |
Return of capital to parent company | (74,000) | (150,000) | 0 |
Payment of common stock dividends | (74,000) | 0 | 0 |
Other financing activities | (2,000) | (2,000) | (7,000) |
Net cash used for financing activities | (222,000) | (83,000) | (527,000) |
Net Change in Cash, Cash Equivalents, and Restricted Cash | (247,000) | (7,000) | 45,000 |
Cash, Cash Equivalents, and Restricted Cash at Beginning of Year | 286,000 | 293,000 | 248,000 |
Cash, Cash Equivalents, and Restricted Cash at End of Year | 39,000 | 286,000 | 293,000 |
Supplemental Cash Flow Information: | |||
Interest, net of amounts capitalized | 63,000 | 71,000 | 80,000 |
Income taxes (net of refunds) | 28,000 | (27,000) | (525,000) |
Noncash transactions — | |||
Accrued property additions at year-end | 34,000 | 35,000 | 35,000 |
Southern Power | |||
Operating Activities: | |||
Consolidated net income | 207,000 | 329,000 | 246,000 |
Adjustments to reconcile consolidated net income to net cash provided from operating activities — | |||
Depreciation and amortization, total | 519,000 | 505,000 | 524,000 |
Deferred income taxes | (25,000) | (74,000) | (244,000) |
Utilization of federal investment tax credits | 340,000 | 734,000 | 5,000 |
Amortization of investment tax credits | (59,000) | (151,000) | (58,000) |
Pension and postretirement funding | 0 | (24,000) | 0 |
Income taxes receivable, non-current | (20,000) | 25,000 | 42,000 |
Impairment charges | 0 | 3,000 | 156,000 |
(Gain) loss on dispositions, net | (39,000) | (24,000) | (3,000) |
Other, net | (5,000) | (9,000) | (4,000) |
Changes in certain current assets and liabilities — | |||
-Receivables | (4,000) | 72,000 | (20,000) |
-Other current assets | (30,000) | (8,000) | (26,000) |
-Accrued taxes | 11,000 | 6,000 | 7,000 |
-Other current liabilities | (14,000) | (38,000) | (19,000) |
-Prepaid income taxes | 20,000 | 39,000 | 25,000 |
Net cash provided from operating activities | 901,000 | 1,385,000 | 631,000 |
Investing Activities: | |||
Business acquisitions, net of cash acquired | (81,000) | (50,000) | (65,000) |
Property additions | (223,000) | (489,000) | (315,000) |
Proceeds from dispositions and asset sales | 666,000 | 572,000 | 203,000 |
Investments in unconsolidated subsidiaries | 0 | (116,000) | 0 |
Payments pursuant to LTSAs | (76,000) | (104,000) | (75,000) |
Other investing activities | 88,000 | 20,000 | 25,000 |
Net cash used for investing activities | 374,000 | (167,000) | (227,000) |
Financing Activities: | |||
Increase (decrease) in notes payable, net | 449,000 | ||
Increase (decrease) in notes payable, net | (274,000) | (105,000) | |
Proceeds — | |||
Short-term borrowings | 0 | 100,000 | 200,000 |
Capital contributions from parent company | 6,000 | 64,000 | 2,000 |
Redemptions and repurchases — | |||
Short-term borrowings | (100,000) | (100,000) | (100,000) |
Senior notes | (825,000) | (600,000) | (350,000) |
Other long-term debt | 0 | 0 | (420,000) |
Return of capital to parent company | 0 | (755,000) | (1,650,000) |
Distributions to noncontrolling interests | (271,000) | (256,000) | (153,000) |
Capital contributions from noncontrolling interests | 363,000 | 196,000 | 2,551,000 |
Purchase of membership interests from noncontrolling interests | (60,000) | 0 | 0 |
Payment of common stock dividends | (201,000) | (206,000) | (312,000) |
Other financing activities | (10,000) | (12,000) | (26,000) |
Net cash used for financing activities | (1,372,000) | (1,120,000) | (363,000) |
Net Change in Cash, Cash Equivalents, and Restricted Cash | (97,000) | 98,000 | 41,000 |
Cash, Cash Equivalents, and Restricted Cash at Beginning of Year | 279,000 | 181,000 | 140,000 |
Cash, Cash Equivalents, and Restricted Cash at End of Year | 182,000 | 279,000 | 181,000 |
Supplemental Cash Flow Information: | |||
Interest, net of amounts capitalized | 147,000 | 167,000 | 173,000 |
Income taxes (net of refunds) | (283,000) | (664,000) | 79,000 |
Noncash transactions — | |||
Accrued property additions at year-end | 89,000 | 57,000 | 31,000 |
Southern Company Gas | |||
Operating Activities: | |||
Consolidated net income | 590,000 | 585,000 | 372,000 |
Adjustments to reconcile consolidated net income to net cash provided from operating activities — | |||
Depreciation and amortization, total | 500,000 | 487,000 | 500,000 |
Deferred income taxes | 56,000 | 213,000 | (1,000) |
Pension and postretirement funding | 0 | (145,000) | 0 |
Impairment charges | 0 | 115,000 | 42,000 |
(Gain) loss on dispositions, net | (22,000) | 0 | (291,000) |
Mark-to-market adjustments | 61,000 | (56,000) | (19,000) |
Other, net | (29,000) | (55,000) | (24,000) |
Changes in certain current assets and liabilities — | |||
-Receivables | (93,000) | 467,000 | (218,000) |
-Natural gas for sale | 18,000 | 44,000 | 49,000 |
-Other current assets | (10,000) | 31,000 | 4,000 |
-Accounts payable | 103,000 | (520,000) | 372,000 |
-Accrued taxes | 13,000 | (69,000) | 10,000 |
-Other current liabilities | (6,000) | (71,000) | (22,000) |
-Prepaid income taxes | 19,000 | 40,000 | (42,000) |
-Accrued compensation | 7,000 | 1,000 | 32,000 |
Net cash provided from operating activities | 1,207,000 | 1,067,000 | 764,000 |
Investing Activities: | |||
Property additions | (1,471,000) | (1,408,000) | (1,388,000) |
Proceeds from dispositions and asset sales | 211,000 | 32,000 | 2,609,000 |
Cost of removal, net of salvage | (100,000) | (82,000) | (96,000) |
Change in construction payables, net | 20,000 | 24,000 | (37,000) |
Investments in unconsolidated subsidiaries | (79,000) | (31,000) | (110,000) |
Returned investment in unconsolidated subsidiaries | 13,000 | 67,000 | 20,000 |
Other investing activities | (11,000) | 12,000 | 0 |
Net cash used for investing activities | (1,417,000) | (1,386,000) | 998,000 |
Financing Activities: | |||
Increase (decrease) in notes payable, net | (326,000) | 0 | (868,000) |
Proceeds — | |||
First mortgage bonds | 325,000 | 300,000 | 300,000 |
Senior notes | 500,000 | 0 | 0 |
Capital contributions from parent company | 216,000 | 821,000 | 24,000 |
Redemptions and repurchases — | |||
Gas facility revenue bonds | 0 | 0 | (200,000) |
Senior notes | 0 | (300,000) | (155,000) |
First mortgage bonds | 0 | (50,000) | 0 |
Return of capital to parent company | 0 | 0 | (400,000) |
Payment of common stock dividends | (533,000) | (471,000) | (468,000) |
Other financing activities | (2,000) | (2,000) | (3,000) |
Net cash used for financing activities | 180,000 | 298,000 | (1,770,000) |
Net Change in Cash, Cash Equivalents, and Restricted Cash | (30,000) | (21,000) | (8,000) |
Cash, Cash Equivalents, and Restricted Cash at Beginning of Year | 49,000 | 70,000 | 78,000 |
Cash, Cash Equivalents, and Restricted Cash at End of Year | 19,000 | 49,000 | 70,000 |
Supplemental Cash Flow Information: | |||
Interest, net of amounts capitalized | 232,000 | 251,000 | 249,000 |
Income taxes (net of refunds) | 25,000 | (41,000) | 524,000 |
Noncash transactions — | |||
Accrued property additions at year-end | $ 142,000 | $ 122,000 | $ 97,000 |
Consolidated Statements of Ca_2
Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Net cash paid for capitalized interest | $ 81 | $ 74 | $ 72 |
Alabama Power | |||
Net cash paid for capitalized interest | 15 | 19 | 22 |
Georgia Power | |||
Net cash paid for capitalized interest | 47 | 35 | 26 |
Mississippi Power | |||
Net cash paid for capitalized interest | 0 | 1 | 0 |
Southern Power | |||
Net cash paid for capitalized interest | 11 | 15 | 17 |
Southern Company Gas | |||
Net cash paid for capitalized interest | $ 7 | $ 6 | $ 7 |
Consolidated Balance Sheets
Consolidated Balance Sheets - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Current Assets: | ||
Cash and cash equivalents | $ 1,065 | $ 1,975 |
Receivables — | ||
Customer accounts | 1,753 | 1,614 |
Energy marketing | 516 | 428 |
Unbilled revenues | 672 | 599 |
Other accounts and notes | 512 | 817 |
Accumulated provision for uncollectible accounts | (118) | (49) |
Materials and supplies | 1,478 | 1,388 |
Fossil fuel for generation | 550 | 521 |
Natural gas for sale | 460 | 479 |
Prepaid expenses | 276 | 314 |
Regulatory assets – asset retirement obligations | 214 | 287 |
Assets from risk management activities, net of collateral | 147 | 183 |
Other regulatory assets | 810 | 885 |
Assets held for sale | 60 | 188 |
Other current assets | 222 | 188 |
Total current assets | 8,617 | 9,817 |
Property, Plant, and Equipment: | ||
In service | 110,516 | 105,114 |
Less: Accumulated depreciation | 32,397 | 30,765 |
Plant in service, net of depreciation | 78,119 | 74,349 |
Nuclear fuel, at amortized cost | 818 | 851 |
Construction work in progress | 8,697 | 7,880 |
Total property, plant, and equipment | 87,634 | 83,080 |
Other Property and Investments: | ||
Goodwill | 5,280 | 5,280 |
Nuclear decommissioning trusts, at fair value | 2,303 | 2,036 |
Equity investments in unconsolidated subsidiaries | 1,362 | 1,303 |
Other intangible assets, net of amortization | 487 | 536 |
Leveraged leases | 556 | 788 |
Miscellaneous property and investments | 398 | 391 |
Total other property and investments | 10,386 | 10,334 |
Deferred Charges and Other Assets: | ||
Operating lease right-of-use assets, net of amortization | 1,802 | 1,800 |
Deferred charges related to income taxes | 796 | 798 |
Unamortized loss on reacquired debt | 280 | 300 |
Regulatory assets – asset retirement obligations, deferred | 4,934 | 4,094 |
Other regulatory assets, deferred | 7,198 | 6,805 |
Assets held for sale, deferred | 0 | 601 |
Other deferred charges and assets | 1,288 | 1,071 |
Total deferred charges and other assets | 16,298 | 15,469 |
Total Assets | 122,935 | 118,700 |
Current Liabilities: | ||
Securities due within one year | 3,507 | 2,989 |
Notes payable | 609 | 2,055 |
Energy marketing trade payables | 494 | 442 |
Accounts payable — | ||
Accounts payable | 2,312 | 2,115 |
Customer deposits | 487 | 496 |
Accrued taxes — | ||
Accrued income taxes | 130 | 0 |
Other accrued taxes | 699 | 659 |
Accrued interest | 513 | 474 |
Accrued compensation | 1,025 | 992 |
Asset retirement obligations | 585 | 504 |
Other regulatory liabilities | 509 | 756 |
Liabilities held for sale | 0 | 5 |
Operating lease obligations | 241 | 229 |
Other current liabilities | 968 | 830 |
Total current liabilities | 12,079 | 12,546 |
Long-Term Debt | 45,073 | 41,798 |
Deferred Credits and Other Liabilities: | ||
Accumulated deferred income taxes | 8,175 | 7,888 |
Deferred credits related to income taxes | 5,767 | 6,078 |
Accumulated deferred ITCs | 2,235 | 2,291 |
Employee benefit obligations | 2,213 | 1,814 |
Operating lease obligations, deferred | 1,611 | 1,615 |
Asset retirement obligations, deferred | 10,099 | 9,282 |
Accrued environmental remediation | 216 | 234 |
Other cost of removal obligations | 2,211 | 2,239 |
Other regulatory liabilities, deferred | 251 | 256 |
Other deferred credits and liabilities | 480 | 609 |
Total deferred credits and other liabilities | 33,258 | 32,306 |
Total Liabilities | 90,410 | 86,650 |
Cumulative preferred stock | ||
Redeemable preferred stock | 291 | 291 |
Common Stockholders' Equity: | ||
Common stock | 5,268 | 5,257 |
Paid-in capital | 11,834 | 11,734 |
Treasury, at cost | (46) | (42) |
Retained earnings (accumulated deficit) | 11,311 | 10,877 |
Accumulated other comprehensive income (loss) | (395) | (321) |
Total common stockholders' equity | 27,972 | 27,505 |
Noncontrolling Interests | 4,262 | 4,254 |
Total Stockholders' Equity (See accompanying statements) | 32,234 | 31,759 |
Total Liabilities and Stockholders' Equity | 122,935 | 118,700 |
Commitments and Contingent Matters (See notes) | ||
Redeemable Preferred Stock, $100 par or stated value | ||
Cumulative preferred stock | ||
Redeemable preferred stock | 48 | 48 |
Redeemable Preferred Stock, $1 par value | ||
Cumulative preferred stock | ||
Redeemable preferred stock | 243 | 243 |
Alabama Power | ||
Current Assets: | ||
Cash and cash equivalents | 530 | 894 |
Receivables — | ||
Customer accounts | 429 | 425 |
Unbilled revenues | 152 | 134 |
Other accounts and notes | 66 | 72 |
Affiliated | 31 | 37 |
Accumulated provision for uncollectible accounts | (43) | (22) |
Materials and supplies | 546 | 512 |
Fossil fuel for generation | 235 | 212 |
Prepaid expenses | 42 | 50 |
Other regulatory assets | 226 | 242 |
Other current assets | 33 | 30 |
Total current assets | 2,247 | 2,586 |
Property, Plant, and Equipment: | ||
In service | 31,816 | 30,023 |
Less: Accumulated depreciation | 10,009 | 9,540 |
Plant in service, net of depreciation | 21,807 | 20,483 |
Nuclear fuel, at amortized cost | 270 | 296 |
Construction work in progress | 866 | 890 |
Total property, plant, and equipment | 22,943 | 21,669 |
Other Property and Investments: | ||
Nuclear decommissioning trusts, at fair value | 1,157 | 1,023 |
Equity investments in unconsolidated subsidiaries | 63 | 66 |
Miscellaneous property and investments | 131 | 128 |
Total other property and investments | 1,351 | 1,217 |
Deferred Charges and Other Assets: | ||
Operating lease right-of-use assets, net of amortization | 151 | 132 |
Deferred charges related to income taxes | 235 | 244 |
Regulatory assets – asset retirement obligations, deferred | 1,441 | 1,019 |
Other regulatory assets, deferred | 2,162 | 2,016 |
Other deferred charges and assets | 273 | 269 |
Total deferred charges and other assets | 4,262 | 3,680 |
Total Assets | 30,803 | 29,152 |
Current Liabilities: | ||
Securities due within one year | 311 | 251 |
Accounts payable — | ||
Affiliated | 316 | 316 |
Other | 545 | 514 |
Customer deposits | 104 | 100 |
Accrued taxes — | ||
Accrued taxes | 152 | 78 |
Accrued interest | 90 | 92 |
Accrued compensation | 212 | 216 |
Asset retirement obligations | 254 | 195 |
Other regulatory liabilities | 108 | 193 |
Operating lease obligations | 51 | 49 |
Other current liabilities | 107 | 105 |
Total current liabilities | 2,199 | 2,060 |
Long-Term Debt | 8,558 | 8,270 |
Deferred Credits and Other Liabilities: | ||
Accumulated deferred income taxes | 3,273 | 3,260 |
Deferred credits related to income taxes | 2,016 | 1,960 |
Accumulated deferred ITCs | 94 | 100 |
Employee benefit obligations | 214 | 206 |
Operating lease obligations, deferred | 119 | 107 |
Asset retirement obligations, deferred | 3,720 | 3,345 |
Other cost of removal obligations | 335 | 412 |
Other regulatory liabilities, deferred | 124 | 146 |
Other deferred credits and liabilities | 50 | 40 |
Total deferred credits and other liabilities | 9,945 | 9,576 |
Total Liabilities | 20,702 | 19,906 |
Cumulative preferred stock | ||
Redeemable preferred stock | 291 | 291 |
Common Stockholders' Equity: | ||
Common stock | 1,222 | 1,222 |
Paid-in capital | 5,413 | 4,755 |
Retained earnings (accumulated deficit) | 3,194 | 3,001 |
Accumulated other comprehensive income (loss) | (19) | (23) |
Total common stockholders' equity | 9,810 | 8,955 |
Total Stockholders' Equity (See accompanying statements) | 9,810 | 8,955 |
Total Liabilities and Stockholders' Equity | 30,803 | 29,152 |
Commitments and Contingent Matters (See notes) | ||
Alabama Power | Redeemable Preferred Stock, $100 par or stated value | ||
Cumulative preferred stock | ||
Redeemable preferred stock | 48 | 48 |
Alabama Power | Redeemable Preferred Stock, $1 par value | ||
Cumulative preferred stock | ||
Redeemable preferred stock | 243 | 243 |
Georgia Power | ||
Current Assets: | ||
Cash and cash equivalents | 9 | 52 |
Receivables — | ||
Customer accounts | 621 | 533 |
Unbilled revenues | 233 | 203 |
Joint owner accounts | 123 | 136 |
Other accounts and notes | 67 | 209 |
Affiliated | 21 | 21 |
Accumulated provision for uncollectible accounts | (26) | (2) |
Materials and supplies | 592 | 501 |
Fossil fuel for generation | 278 | 272 |
Prepaid expenses | 54 | 63 |
Regulatory assets – storm damage | 213 | 213 |
Regulatory assets – asset retirement obligations | 166 | 254 |
Other regulatory assets | 248 | 263 |
Other current assets | 89 | 77 |
Total current assets | 2,688 | 2,795 |
Property, Plant, and Equipment: | ||
In service | 39,682 | 38,137 |
Less: Accumulated depreciation | 12,251 | 11,753 |
Plant in service, net of depreciation | 27,431 | 26,384 |
Nuclear fuel, at amortized cost | 548 | 555 |
Construction work in progress | 6,857 | 5,650 |
Total property, plant, and equipment | 34,836 | 32,589 |
Other Property and Investments: | ||
Nuclear decommissioning trusts, at fair value | 1,145 | 1,013 |
Equity investments in unconsolidated subsidiaries | 51 | 52 |
Miscellaneous property and investments | 63 | 64 |
Total other property and investments | 1,259 | 1,129 |
Deferred Charges and Other Assets: | ||
Operating lease right-of-use assets, net of amortization | 1,308 | 1,428 |
Deferred charges related to income taxes | 527 | 519 |
Regulatory assets – asset retirement obligations, deferred | 3,291 | 2,865 |
Other regulatory assets, deferred | 2,692 | 2,716 |
Other deferred charges and assets | 479 | 500 |
Total deferred charges and other assets | 8,297 | 8,028 |
Total Assets | 47,080 | 44,541 |
Current Liabilities: | ||
Securities due within one year | 542 | 1,025 |
Notes payable | 60 | 365 |
Accounts payable — | ||
Affiliated | 597 | 512 |
Other | 753 | 711 |
Customer deposits | 276 | 283 |
Accrued taxes — | ||
Accrued taxes | 407 | 407 |
Accrued interest | 130 | 118 |
Accrued compensation | 233 | 233 |
Asset retirement obligations | 287 | 265 |
Other regulatory liabilities | 228 | 447 |
Over recovered regulatory clause liabilities | 113 | 0 |
Operating lease obligations | 151 | 144 |
Other current liabilities | 254 | 187 |
Total current liabilities | 4,031 | 4,697 |
Long-Term Debt | 12,428 | 10,791 |
Deferred Credits and Other Liabilities: | ||
Accumulated deferred income taxes | 3,272 | 3,257 |
Deferred credits related to income taxes | 2,588 | 2,862 |
Accumulated deferred ITCs | 273 | 255 |
Employee benefit obligations | 586 | 540 |
Operating lease obligations, deferred | 1,156 | 1,282 |
Asset retirement obligations, deferred | 5,978 | 5,519 |
Accrued environmental remediation | 0 | 0 |
Other deferred credits and liabilities | 267 | 273 |
Total deferred credits and other liabilities | 14,120 | 13,988 |
Total Liabilities | 30,579 | 29,476 |
Common Stockholders' Equity: | ||
Common stock | 398 | 398 |
Paid-in capital | 12,361 | 10,962 |
Retained earnings (accumulated deficit) | 3,789 | 3,756 |
Accumulated other comprehensive income (loss) | (47) | (51) |
Total common stockholders' equity | 16,501 | 15,065 |
Total Stockholders' Equity (See accompanying statements) | 16,501 | 15,065 |
Total Liabilities and Stockholders' Equity | 47,080 | 44,541 |
Commitments and Contingent Matters (See notes) | ||
Mississippi Power | ||
Current Assets: | ||
Cash and cash equivalents | 39 | 286 |
Receivables — | ||
Customer accounts | 34 | 35 |
Unbilled revenues | 38 | 39 |
Other accounts and notes | 32 | 26 |
Affiliated | 32 | 27 |
Materials and supplies | 65 | 61 |
Fossil fuel for generation | 24 | 26 |
Other regulatory assets | 60 | 99 |
Other current assets | 20 | 10 |
Total current assets | 344 | 609 |
Property, Plant, and Equipment: | ||
In service | 5,011 | 4,857 |
Less: Accumulated depreciation | 1,545 | 1,463 |
Plant in service, net of depreciation | 3,466 | 3,394 |
Construction work in progress | 146 | 126 |
Total property, plant, and equipment | 3,612 | 3,520 |
Other Property and Investments: | ||
Total other property and investments | 151 | 131 |
Deferred Charges and Other Assets: | ||
Operating lease right-of-use assets, net of amortization | 9 | 6 |
Deferred charges related to income taxes | 32 | 32 |
Regulatory assets – asset retirement obligations, deferred | 201 | 210 |
Other regulatory assets, deferred | 388 | 360 |
Accumulated deferred income taxes | 129 | 139 |
Other deferred charges and assets | 55 | 34 |
Total deferred charges and other assets | 805 | 775 |
Total Assets | 4,912 | 5,035 |
Current Liabilities: | ||
Securities due within one year | 406 | 281 |
Notes payable | 25 | 0 |
Accounts payable — | ||
Affiliated | 63 | 76 |
Other | 109 | 75 |
Accrued taxes — | ||
Accrued taxes | 114 | 105 |
Accrued interest | 15 | 15 |
Accrued compensation | 34 | 35 |
Asset retirement obligations | 27 | 33 |
Other regulatory liabilities | 49 | 21 |
Over recovered regulatory clause liabilities | 34 | 29 |
Operating lease obligations | 2 | 2 |
Other current liabilities | 40 | 64 |
Total current liabilities | 916 | 734 |
Long-Term Debt | 1,013 | 1,308 |
Deferred Credits and Other Liabilities: | ||
Accumulated deferred income taxes | 447 | 424 |
Deferred credits related to income taxes | 287 | 352 |
Employee benefit obligations | 113 | 99 |
Operating lease obligations, deferred | 7 | 4 |
Asset retirement obligations, deferred | 150 | 157 |
Other cost of removal obligations | 194 | 189 |
Other regulatory liabilities, deferred | 15 | 76 |
Other deferred credits and liabilities | 35 | 44 |
Total deferred credits and other liabilities | 1,241 | 1,341 |
Total Liabilities | 3,170 | 3,383 |
Common Stockholders' Equity: | ||
Common stock | 38 | 38 |
Paid-in capital | 4,460 | 4,449 |
Retained earnings (accumulated deficit) | (2,754) | (2,832) |
Accumulated other comprehensive income (loss) | (2) | (3) |
Total common stockholders' equity | 1,742 | 1,652 |
Total Stockholders' Equity (See accompanying statements) | 1,742 | 1,652 |
Total Liabilities and Stockholders' Equity | 4,912 | 5,035 |
Commitments and Contingent Matters (See notes) | ||
Southern Power | ||
Current Assets: | ||
Cash and cash equivalents | 182 | 279 |
Receivables — | ||
Customer accounts | 125 | 107 |
Other accounts and notes | 27 | 73 |
Affiliated | 37 | 30 |
Materials and supplies | 157 | 191 |
Prepaid income taxes | 11 | 36 |
Other current assets | 36 | 43 |
Total current assets | 575 | 759 |
Property, Plant, and Equipment: | ||
In service | 13,904 | 13,270 |
Less: Accumulated depreciation | 2,842 | 2,464 |
Plant in service, net of depreciation | 11,062 | 10,806 |
Construction work in progress | 127 | 515 |
Total property, plant, and equipment | 11,189 | 11,321 |
Other Property and Investments: | ||
Intangible assets, net of amortization | 302 | 322 |
Equity investments in unconsolidated subsidiaries | 19 | 28 |
Total other property and investments | 321 | 350 |
Deferred Charges and Other Assets: | ||
Operating lease right-of-use assets, net of amortization | 415 | 369 |
Prepaid LTSAs | 155 | 128 |
Income taxes receivable, non-current | 25 | 5 |
Assets held for sale, deferred | 0 | 601 |
Accumulated deferred income taxes | 262 | 551 |
Other deferred charges and assets | 293 | 216 |
Total deferred charges and other assets | 1,150 | 1,870 |
Total Assets | 13,235 | 14,300 |
Current Liabilities: | ||
Securities due within one year | 299 | 824 |
Notes payable | 175 | 549 |
Accounts payable — | ||
Affiliated | 65 | 56 |
Other | 92 | 85 |
Accrued taxes — | ||
Accrued taxes | 30 | 26 |
Accrued interest | 32 | 32 |
Operating lease obligations | 25 | 22 |
Other current liabilities | 132 | 132 |
Total current liabilities | 825 | 1,704 |
Long-Term Debt | 3,393 | 3,574 |
Deferred Credits and Other Liabilities: | ||
Accumulated deferred income taxes | 123 | 115 |
Accumulated deferred ITCs | 1,672 | 1,731 |
Operating lease obligations, deferred | 426 | 376 |
Other deferred credits and liabilities | 165 | 178 |
Total deferred credits and other liabilities | 2,386 | 2,400 |
Total Liabilities | 6,604 | 7,678 |
Common Stockholders' Equity: | ||
Common stock | 0 | 0 |
Paid-in capital | 914 | 909 |
Retained earnings (accumulated deficit) | 1,522 | 1,485 |
Accumulated other comprehensive income (loss) | (67) | (26) |
Total common stockholders' equity | 2,369 | 2,368 |
Noncontrolling Interests | 4,262 | 4,254 |
Total Stockholders' Equity (See accompanying statements) | 6,631 | 6,622 |
Total Liabilities and Stockholders' Equity | 13,235 | 14,300 |
Commitments and Contingent Matters (See notes) | ||
Southern Company Gas | ||
Current Assets: | ||
Cash and cash equivalents | 17 | 46 |
Receivables — | ||
Customer accounts | 353 | 323 |
Energy marketing | 516 | 428 |
Unbilled revenues | 219 | 183 |
Other accounts and notes | 51 | 114 |
Affiliated | 4 | 5 |
Accumulated provision for uncollectible accounts | (40) | (18) |
Natural gas for sale | 460 | 479 |
Prepaid expenses | 48 | 65 |
Assets from risk management activities, net of collateral | 118 | 177 |
Other regulatory assets | 102 | 92 |
Assets held for sale | 0 | 171 |
Other current assets | 38 | 41 |
Total current assets | 1,886 | 2,106 |
Property, Plant, and Equipment: | ||
In service | 17,611 | 16,344 |
Less: Accumulated depreciation | 4,821 | 4,650 |
Plant in service, net of depreciation | 12,790 | 11,694 |
Construction work in progress | 648 | 613 |
Total property, plant, and equipment | 13,438 | 12,307 |
Other Property and Investments: | ||
Goodwill | 5,015 | 5,015 |
Equity investments in unconsolidated subsidiaries | 1,290 | 1,251 |
Other intangible assets, net of amortization | 51 | 70 |
Miscellaneous property and investments | 19 | 20 |
Total other property and investments | 6,375 | 6,356 |
Deferred Charges and Other Assets: | ||
Operating lease right-of-use assets, net of amortization | 81 | 93 |
Other regulatory assets, deferred | 615 | 618 |
Other deferred charges and assets | 235 | 207 |
Total deferred charges and other assets | 931 | 918 |
Total Assets | 22,630 | 21,687 |
Current Liabilities: | ||
Securities due within one year | 333 | 0 |
Notes payable | 324 | 650 |
Energy marketing trade payables | 494 | 442 |
Accounts payable — | ||
Affiliated | 56 | 41 |
Other | 373 | 315 |
Customer deposits | 90 | 96 |
Accrued taxes — | ||
Accrued taxes | 83 | 71 |
Accrued interest | 58 | 52 |
Accrued compensation | 106 | 100 |
Other regulatory liabilities | 122 | 94 |
Operating lease obligations | 15 | 14 |
Other current liabilities | 150 | 149 |
Total current liabilities | 2,189 | 2,010 |
Long-Term Debt | 6,293 | 5,845 |
Deferred Credits and Other Liabilities: | ||
Accumulated deferred income taxes | 1,265 | 1,219 |
Deferred credits related to income taxes | 847 | 874 |
Employee benefit obligations | 283 | 265 |
Operating lease obligations, deferred | 67 | 78 |
Accrued environmental remediation | 216 | 233 |
Other cost of removal obligations | 1,649 | 1,606 |
Other deferred credits and liabilities | 54 | 51 |
Total deferred credits and other liabilities | 4,381 | 4,326 |
Total Liabilities | 12,863 | 12,181 |
Common Stockholders' Equity: | ||
Common stock | 9,930 | 9,697 |
Retained earnings (accumulated deficit) | (141) | (198) |
Accumulated other comprehensive income (loss) | (22) | 7 |
Total common stockholders' equity | 9,767 | 9,506 |
Total Stockholders' Equity (See accompanying statements) | 9,767 | 9,506 |
Total Liabilities and Stockholders' Equity | 22,630 | 21,687 |
Commitments and Contingent Matters (See notes) |
Consolidated Balance Sheets (Pa
Consolidated Balance Sheets (Parenthetical) - USD ($) | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Other intangible assets, amortization | $ 328,000,000 | $ 280,000,000 |
Common Stockholders' Equity: | ||
Common stock, par value (in dollars per share) | $ 5 | $ 5 |
Common stock, shares authorized (in shares) | 1,500,000,000 | 1,500,000,000 |
Common stock, shares issued (in shares) | 1,100,000,000 | 1,100,000,000 |
Treasury shares (in shares) | 1,000,000 | 1,000,000 |
Redeemable Preferred Stock | ||
Cumulative preferred stock | ||
Annual dividend requirement | $ 15,000,000 | $ 15,000,000 |
Redeemable Preferred Stock, $100 par or stated value | ||
Cumulative preferred stock | ||
Par value (in dollars per share) | $ 100 | $ 100 |
Shares authorized (in shares) | 10,000,000 | 10,000,000 |
Shares outstanding (in shares) | 500,000 | 500,000 |
Redeemable Preferred Stock, $100 par or stated value | Minimum | ||
Cumulative preferred stock | ||
Dividend rate | 4.20% | 4.20% |
Redeemable Preferred Stock, $100 par or stated value | Maximum | ||
Cumulative preferred stock | ||
Dividend rate | 4.92% | 4.92% |
Redeemable Preferred Stock, $1 par value | ||
Cumulative preferred stock | ||
Par value (in dollars per share) | $ 1 | $ 1 |
Dividend rate | 5.00% | 5.00% |
Shares authorized (in shares) | 28,000,000 | 28,000,000 |
Shares outstanding (in shares) | 10,000,000 | 10,000,000 |
Alabama Power | ||
Common Stockholders' Equity: | ||
Common stock, par value (in dollars per share) | $ 40 | $ 40 |
Common stock, shares authorized (in shares) | 40,000,000 | 40,000,000 |
Common stock, shares outstanding (in shares) | 31,000,000 | 31,000,000 |
Alabama Power | Redeemable Preferred Stock | ||
Cumulative preferred stock | ||
Annual dividend requirement | $ 15,000,000 | $ 15,000,000 |
Alabama Power | Redeemable Preferred Stock, $100 par or stated value | ||
Cumulative preferred stock | ||
Par value (in dollars per share) | $ 100 | $ 100 |
Shares authorized (in shares) | 3,900,000 | 3,900,000 |
Shares outstanding (in shares) | 500,000 | 500,000 |
Alabama Power | Redeemable Preferred Stock, $100 par or stated value | Minimum | ||
Cumulative preferred stock | ||
Dividend rate | 4.20% | 4.20% |
Alabama Power | Redeemable Preferred Stock, $100 par or stated value | Maximum | ||
Cumulative preferred stock | ||
Dividend rate | 4.92% | 4.92% |
Alabama Power | Redeemable Preferred Stock, $1 par value | ||
Cumulative preferred stock | ||
Par value (in dollars per share) | $ 1 | $ 1 |
Dividend rate | 5.00% | 5.00% |
Shares authorized (in shares) | 27,500,000 | 27,500,000 |
Shares outstanding (in shares) | 10,000,000 | 10,000,000 |
Alabama Power | Redeemable Preferred Stock, $25 stated value | ||
Cumulative preferred stock | ||
Par value (in dollars per share) | $ 25 | $ 25 |
Georgia Power | ||
Common Stockholders' Equity: | ||
Common stock, shares authorized (in shares) | 20,000,000 | 20,000,000 |
Common stock, shares outstanding (in shares) | 9,000,000 | 9,000,000 |
Mississippi Power | ||
Common Stockholders' Equity: | ||
Common stock, shares authorized (in shares) | 1,000,000 | 1,000,000 |
Common stock, shares outstanding (in shares) | 1,000,000 | 1,000,000 |
Southern Power | ||
Other intangible assets, amortization | $ 89,000,000 | $ 69,000,000 |
Cumulative preferred stock | ||
Par value (in dollars per share) | $ 0.01 | $ 0.01 |
Common Stockholders' Equity: | ||
Common stock, shares authorized (in shares) | 1,000,000 | 1,000,000 |
Common stock, shares outstanding (in shares) | 1,000 | 1,000 |
Southern Company Gas | ||
Other intangible assets, amortization | $ 195,000,000 | $ 176,000,000 |
Common Stockholders' Equity: | ||
Common stock, par value (in dollars per share) | $ 0.01 | $ 0.01 |
Common stock, shares authorized (in shares) | 100,000,000 | 100,000,000 |
Common stock, shares outstanding (in shares) | 100 | 100 |
Consolidated Statements of Stoc
Consolidated Statements of Stockholders' Equity - USD ($) shares in Millions, $ in Millions | Total | Common Stock | Treasury | Paid-In Capital | Retained Earnings | Accumulated Other Comprehensive Income (Loss) | Noncontrolling Interests | Alabama Power | Alabama PowerCommon Stock | Alabama PowerPaid-In Capital | Alabama PowerRetained Earnings | Alabama PowerAccumulated Other Comprehensive Income (Loss) | Georgia Power | Georgia PowerCommon Stock | Georgia PowerPaid-In Capital | Georgia PowerRetained Earnings | Georgia PowerAccumulated Other Comprehensive Income (Loss) | Mississippi Power | Mississippi PowerCommon Stock | Mississippi PowerPaid-In Capital | Mississippi PowerRetained Earnings | Mississippi PowerAccumulated Other Comprehensive Income (Loss) | Southern Power | Southern PowerPaid-In Capital | Southern PowerRetained Earnings | Southern PowerAccumulated Other Comprehensive Income (Loss) | Southern PowerTotal Common Stockholder's Equity | Southern PowerNoncontrolling Interests | Southern Company Gas | Southern Company GasPaid-In Capital | Southern Company GasRetained Earnings | Southern Company GasAccumulated Other Comprehensive Income (Loss) | |
Beginning balance (in shares) at Dec. 31, 2017 | 1,009 | 1 | 31 | 9 | 1 | ||||||||||||||||||||||||||||
Beginning balance at Dec. 31, 2017 | $ 25,528 | $ 5,038 | $ (36) | $ 10,469 | $ 8,885 | $ (189) | $ 1,361 | $ 6,829 | $ 1,222 | $ 2,986 | $ 2,647 | $ (26) | $ 11,931 | $ 398 | $ 7,328 | $ 4,215 | $ (10) | $ 1,358 | $ 38 | $ 4,529 | $ (3,205) | $ (4) | $ 6,498 | $ 3,662 | $ 1,478 | $ (2) | $ 5,138 | $ 1,360 | $ 9,022 | $ 9,214 | $ (212) | $ 20 | |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | |||||||||||||||||||||||||||||||||
Consolidated net income (loss) | 2,284 | 2,226 | 58 | ||||||||||||||||||||||||||||||
Net income after dividends on preferred stock | 2,226 | 930 | 930 | 235 | 235 | 187 | 372 | 372 | |||||||||||||||||||||||||
Net Income | 2,300 | 945 | 793 | 793 | 236 | 246 | 187 | 187 | 59 | 372 | |||||||||||||||||||||||
Return of capital to parent company | (1,650) | (1,650) | (1,650) | (400) | (400) | ||||||||||||||||||||||||||||
Capital contributions from parent company | 522 | 522 | 2,994 | 2,994 | 17 | 17 | 2 | 2 | 2 | 42 | 42 | ||||||||||||||||||||||
Other comprehensive income (loss) | 26 | 26 | 4 | 4 | 3 | 3 | 14 | 14 | 14 | 2 | 2 | ||||||||||||||||||||||
Stock issued (in shares) | 26 | ||||||||||||||||||||||||||||||||
Stock issued | 1,090 | $ 126 | 964 | ||||||||||||||||||||||||||||||
Stock-based compensation | 84 | 84 | |||||||||||||||||||||||||||||||
Cash dividends on common stock | (2,425) | (2,425) | (801) | (801) | (1,396) | (1,396) | (312) | (312) | (312) | (468) | (468) | ||||||||||||||||||||||
Contributions from noncontrolling interests | 1,372 | 1,372 | 1,372 | 1,372 | |||||||||||||||||||||||||||||
Distributions to noncontrolling interests | (164) | (164) | (164) | (164) | |||||||||||||||||||||||||||||
Sale of noncontrolling interests | 1,273 | (417) | 1,690 | 1,273 | (417) | (417) | 1,690 | ||||||||||||||||||||||||||
Other | (29) | $ (2) | (6) | 20 | (40) | (1) | (7) | (1) | (6) | (2) | (2) | (1) | (1) | 5 | 3 | (1) | 4 | 6 | (1) | 0 | 0 | (4) | 4 | ||||||||||
Ending balance (in shares) at Dec. 31, 2018 | 1,035 | 1 | 31 | 9 | 1 | ||||||||||||||||||||||||||||
Ending balance at Dec. 31, 2018 | 29,039 | $ 5,164 | $ (38) | 11,094 | 8,706 | (203) | 4,316 | 7,477 | $ 1,222 | 3,508 | 2,775 | (28) | 14,323 | $ 398 | 10,322 | 3,612 | (9) | 1,609 | $ 38 | 4,546 | (2,971) | (4) | 7,284 | 1,600 | 1,352 | 16 | 2,968 | 4,316 | 8,570 | 8,856 | (312) | 26 | |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | |||||||||||||||||||||||||||||||||
Consolidated net income (loss) | 4,729 | 4,739 | (10) | ||||||||||||||||||||||||||||||
Net income after dividends on preferred stock | 4,739 | 1,070 | 1,070 | 139 | 139 | 339 | 585 | 585 | |||||||||||||||||||||||||
Net Income | 4,744 | 1,085 | 1,720 | 1,720 | 139 | 329 | 339 | 339 | (10) | 585 | |||||||||||||||||||||||
Return of capital to parent company | (150) | (150) | (755) | (755) | (755) | ||||||||||||||||||||||||||||
Capital contributions from parent company | 1,247 | 1,247 | 640 | 640 | 53 | 53 | 64 | 64 | 64 | 841 | 841 | ||||||||||||||||||||||
Other comprehensive income (loss) | (118) | (118) | 4 | 4 | (42) | (42) | 1 | 1 | (42) | (42) | (42) | (19) | (19) | ||||||||||||||||||||
Issuance of equity units | [1] | (198) | (198) | ||||||||||||||||||||||||||||||
Stock issued (in shares) | 19 | ||||||||||||||||||||||||||||||||
Stock issued | 844 | $ 93 | 751 | ||||||||||||||||||||||||||||||
Stock-based compensation | 66 | 66 | |||||||||||||||||||||||||||||||
Cash dividends on common stock | (2,570) | (2,570) | (844) | (844) | (1,576) | (1,576) | (206) | (206) | (206) | (471) | (471) | ||||||||||||||||||||||
Contributions from noncontrolling interests | 276 | 276 | 276 | 276 | |||||||||||||||||||||||||||||
Distributions to noncontrolling interests | (327) | (327) | (327) | (327) | |||||||||||||||||||||||||||||
Other | 18 | $ (4) | 21 | 2 | (1) | 1 | 1 | (1) | (1) | ||||||||||||||||||||||||
Ending balance (in shares) at Dec. 31, 2019 | 1,054 | 1 | 31 | 9 | 1 | ||||||||||||||||||||||||||||
Ending balance at Dec. 31, 2019 | 31,759 | $ 5,257 | $ (42) | 11,734 | 10,877 | (321) | 4,254 | 8,955 | $ 1,222 | 4,755 | 3,001 | (23) | 15,065 | $ 398 | 10,962 | 3,756 | (51) | 1,652 | $ 38 | 4,449 | (2,832) | (3) | 6,622 | 909 | 1,485 | (26) | 2,368 | 4,254 | 9,506 | 9,697 | (198) | 7 | |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | |||||||||||||||||||||||||||||||||
Consolidated net income (loss) | 3,088 | 3,119 | (31) | ||||||||||||||||||||||||||||||
Net income after dividends on preferred stock | 3,119 | 1,150 | 1,150 | 152 | 152 | 238 | 590 | 590 | |||||||||||||||||||||||||
Net Income | 3,103 | 1,165 | 1,575 | 1,575 | 152 | 207 | 238 | 238 | (31) | 590 | |||||||||||||||||||||||
Return of capital to parent company | (74) | (74) | |||||||||||||||||||||||||||||||
Capital contributions from parent company | 658 | 658 | 1,399 | 1,399 | 86 | 86 | 2 | 2 | 2 | 233 | 233 | ||||||||||||||||||||||
Other comprehensive income (loss) | (75) | (75) | 4 | 4 | 4 | 4 | 1 | 1 | (42) | (42) | (42) | (29) | (29) | ||||||||||||||||||||
Stock issued (in shares) | 4 | ||||||||||||||||||||||||||||||||
Stock issued | 74 | $ 11 | 63 | ||||||||||||||||||||||||||||||
Stock-based compensation | 44 | 44 | |||||||||||||||||||||||||||||||
Cash dividends on common stock | (2,685) | (2,685) | (957) | (957) | (1,542) | (1,542) | (74) | (74) | (201) | (201) | (201) | (533) | (533) | ||||||||||||||||||||
Contributions from noncontrolling interests | 307 | 307 | 307 | 307 | |||||||||||||||||||||||||||||
Distributions to noncontrolling interests | (271) | (271) | (271) | (271) | |||||||||||||||||||||||||||||
Sale of noncontrolling interests | 65 | (2) | 67 | 65 | (2) | (2) | 67 | ||||||||||||||||||||||||||
Purchase of membership interests from noncontrolling interests | (60) | 5 | (65) | (60) | 5 | 5 | (65) | ||||||||||||||||||||||||||
Other | (12) | $ (4) | (10) | 1 | 1 | (1) | (1) | 2 | 1 | 1 | 1 | ||||||||||||||||||||||
Ending balance (in shares) at Dec. 31, 2020 | 1,058 | 1 | 31 | 9 | 1 | ||||||||||||||||||||||||||||
Ending balance at Dec. 31, 2020 | $ 32,234 | $ 5,268 | $ (46) | $ 11,834 | $ 11,311 | $ (395) | $ 4,262 | $ 9,810 | $ 1,222 | $ 5,413 | $ 3,194 | $ (19) | $ 16,501 | $ 398 | $ 12,361 | $ 3,789 | $ (47) | $ 1,742 | $ 38 | $ 4,460 | $ (2,754) | $ (2) | $ 6,631 | $ 914 | $ 1,522 | $ (67) | $ 2,369 | $ 4,262 | $ 9,767 | $ 9,930 | $ (141) | $ (22) | |
[1] | See Note 8 under "Equity Units" for additional information. |
Consolidated Statements of St_2
Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Statement of Stockholders' Equity [Abstract] | |||
Cash dividends (in dollars per share) | $ 2.5400 | $ 2.4600 | $ 2.3800 |
SUMMARY OF SIGNIFICANT ACCOUNTI
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES | 12 Months Ended |
Dec. 31, 2020 | |
Accounting Policies [Abstract] | |
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES | SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES General Southern Company is the parent company of three traditional electric operating companies, as well as Southern Power, Southern Company Gas, SCS, Southern Linc, Southern Holdings, Southern Nuclear, PowerSecure, and other direct and indirect subsidiaries. The traditional electric operating companies – Alabama Power, Georgia Power, and Mississippi Power – are vertically integrated utilities providing electric service in three Southeastern states. In January 2019, Southern Company completed the sale of Gulf Power (another traditional electric operating company through December 31, 2018) to NextEra Energy. Southern Power develops, constructs, acquires, owns, and manages power generation assets, including renewable energy and battery energy storage projects, and sells electricity at market-based rates in the wholesale market. Southern Company Gas distributes natural gas through natural gas distribution utilities, including Nicor Gas (Illinois), Atlanta Gas Light (Georgia), Virginia Natural Gas, and Chattanooga Gas (Tennessee). In 2018, Southern Company Gas sold its other natural gas utilities – Elizabethtown Gas (New Jersey), Florida City Gas, and Elkton Gas (Maryland). Southern Company Gas is also involved in several other complementary businesses including gas pipeline investments, wholesale gas services, and gas marketing services. SCS, the system service company, provides, at cost, specialized services to Southern Company and its subsidiary companies. Southern Linc provides digital wireless communications for use by Southern Company and its subsidiary companies and also markets these services to the public and provides fiber optics services within the Southeast. Southern Holdings is an intermediate holding company subsidiary, primarily for Southern Company's leveraged lease and other investments. Southern Nuclear operates and provides services to the Southern Company system's nuclear power plants, including Alabama Power's Plant Farley and Georgia Power's Plant Hatch and Plant Vogtle Units 1 and 2, and is currently managing construction and start-up of Plant Vogtle Units 3 and 4, which are co-owned by Georgia Power. PowerSecure provides energy solutions to electric utilities and their customers in the areas of distributed generation, energy storage and renewables, and energy efficiency. See Note 15 for information regarding disposition activities, including Southern Company's sale of Gulf Power. The Registrants' financial statements reflect investments in subsidiaries on a consolidated basis. Intercompany transactions have been eliminated in consolidation. The equity method is used for investments in entities in which a Registrant has significant influence but does not have control and for VIEs where a Registrant has an equity investment but is not the primary beneficiary. Southern Power has controlling ownership in certain legal entities for which the contractual provisions represent profit-sharing arrangements because the allocations of cash distributions and tax benefits are not based on fixed ownership percentages. For these arrangements, the noncontrolling interest is accounted for under a balance sheet approach utilizing the HLBV method. The HLBV method calculates each partner's share of income based on the change in net equity the partner can legally claim in a HLBV at the end of the period compared to the beginning of the period. See "Variable Interest Entities" herein and Note 7 for additional information. The traditional electric operating companies, Southern Power, certain subsidiaries of Southern Company Gas, and certain other subsidiaries are subject to regulation by the FERC, and the traditional electric operating companies and the natural gas distribution utilities are also subject to regulation by their respective state PSCs or other applicable state regulatory agencies. As such, the respective financial statements of the applicable Registrants reflect the effects of rate regulation in accordance with GAAP and comply with the accounting policies and practices prescribed by relevant state PSCs or other applicable state regulatory agencies. The preparation of financial statements in conformity with GAAP requires the use of estimates, and the actual results may differ from those estimates. Certain prior years' data presented in the financial statements have been reclassified to conform to the current year presentation. These reclassifications had no impact on the Registrants' results of operations, financial position, or cash flows. At December 31, 2020 and/or 2019, Southern Company, Southern Power, and Southern Company Gas each had assets and liabilities held for sale on their balance sheets. Unless otherwise noted, the disclosures herein related to specific asset and liability balances at December 31, 2020 and 2019 exclude assets and liabilities held for sale. See Note 15 under "Assets Held for Sale" for additional information including major classes of assets and liabilities classified as held for sale by Southern Company, Southern Power, and Southern Company Gas. Recently Adopted Accounting Standards Effective January 1, 2019, the Registrants adopted ASU No. 2016-02, Leases (Topic 842) (ASU 2016-02). ASU 2016-02 required lessees to recognize on the balance sheet a lease liability and a right-of-use asset for all leases. ASU 2016-02 also changed the recognition, measurement, and presentation of expense associated with leases and provided clarification regarding the identification of certain components of contracts that would represent a lease. Lessor accounting was relatively unchanged and there was no change to the accounting for existing leveraged leases. See Note 9 for additional information and related disclosures. Affiliate Transactions The traditional electric operating companies, Southern Power, and Southern Company Gas have agreements with SCS under which certain of the following services are rendered to them at direct or allocated cost: general executive and advisory, general and design engineering, operations, purchasing, accounting, finance, treasury, legal, tax, information technology, marketing, auditing, insurance and pension administration, human resources, systems and procedures, digital wireless communications, cellular tower space, and other services with respect to business and operations, construction management, and Southern Company power pool transactions. These costs are primarily included in other operations and maintenance expenses or capitalized to property, plant, and equipment. Costs for these services from SCS in 2020, 2019, and 2018 were as follows: Alabama Georgia Mississippi Southern Southern Company Gas (in millions) 2020 $ 478 $ 639 $ 149 $ 87 $ 237 2019 527 704 118 90 183 2018 508 653 104 98 194 Alabama Power and Georgia Power also have agreements with Southern Nuclear under which Southern Nuclear renders the following nuclear-related services at cost: general executive and advisory services; general operations, management, and technical services; administrative services including procurement, accounting, employee relations, systems, and procedures services; strategic planning and budgeting services; other services with respect to business and operations; and, for Georgia Power, construction management. These costs are primarily included in other operations and maintenance expenses or capitalized to property, plant, and equipment. Costs for these services in 2020, 2019, and 2018 amounted to $262 million, $256 million, and $247 million, respectively, for Alabama Power and $883 million, $760 million, and $780 million, respectively, for Georgia Power. See Note 2 under "Georgia Power – Nuclear Construction" for additional information regarding Southern Nuclear's construction management of Plant Vogtle Units 3 and 4 for Georgia Power. Cost allocation methodologies used by SCS and Southern Nuclear prior to the repeal of the Public Utility Holding Company Act of 1935, as amended, were approved by the SEC. Subsequently, additional cost allocation methodologies have been reported to the FERC and management believes they are reasonable. The FERC permits services to be rendered at cost by system service companies. Alabama Power's and Georgia Power's power purchases from affiliates through the Southern Company power pool are included in purchased power, affiliates on their respective statements of income. Mississippi Power's and Southern Power's power purchases from affiliates through the Southern Company power pool are included in purchased power on their respective statements of income and were as follows: Mississippi Southern (in millions) 2020 $ 4 $ 8 2019 3 14 2018 15 41 Georgia Power has entered into several PPAs with Southern Power for capacity and energy. Georgia Power's total expenses associated with these PPAs were $141 million, $177 million, and $216 million in 2020, 2019, and 2018, respectively. Southern Power's total revenues from all PPAs with Georgia Power, included in wholesale revenue affiliates on Southern Power's consolidated statements of income, were $139 million, $174 million, and $215 million for 2020, 2019, and 2018, respectively. Included within these revenues were affiliate PPAs accounted for as operating leases, which totaled $115 million, $116 million, and $65 million for 2020, 2019, and 2018, respectively. See Note 9 for additional information. SCS (as agent for Alabama Power, Georgia Power, and Southern Power) and Southern Company Gas have long-term interstate natural gas transportation agreements with SNG that are governed by the terms and conditions of SNG's natural gas tariff and are subject to FERC regulation. See Note 7 under "Southern Company Gas – Equity Method Investments" for additional information. Transportation costs under these agreements in 2020, 2019, and 2018 were as follows: Alabama Georgia Southern Southern Company Gas (in millions) 2020 $ 15 $ 108 $ 29 $ 29 2019 17 99 28 31 2018 8 101 25 32 In 2018, SNG purchased the natural gas lateral pipeline serving Plant McDonough Units 4 through 6 from Georgia Power at net book value, as approved by the Georgia PSC. In January 2020, SNG paid Georgia Power $142 million, which included $71 million contributed to SNG by Southern Company Gas for its proportionate share. During the interim period, Georgia Power received a discounted shipping rate to reflect the deferred consideration and SNG constructed an extension to the pipeline. SCS, as agent for the traditional electric operating companies and Southern Power, has agreements with certain subsidiaries of Southern Company Gas to purchase natural gas. Natural gas purchases made under these agreements were immaterial for Alabama Power and Mississippi Power and as follows for Georgia Power and Southern Power in 2020, 2019, and 2018: Georgia Southern (in millions) 2020 $ — $ 26 2019 4 64 2018 21 119 Alabama Power and Mississippi Power jointly own Plant Greene County. The companies have an agreement under which Alabama Power operates Plant Greene County and Mississippi Power reimburses Alabama Power for its proportionate share of non-fuel operations and maintenance expenses, which totaled $9 million, $9 million, and $8 million in 2020, 2019, and 2018, respectively. See Note 5 under "Joint Ownership Agreements" for additional information. The traditional electric operating companies each have agreements with Gulf Power. Alabama Power previously made transmission system upgrades to ensure firm delivery of energy under a non-affiliate PPA from the Central Alabama Generating Station, and, under a related tariff, received $11 million from Gulf Power in 2018. Gulf Power owns a 25% portion of Plant Scherer Unit 3. Georgia Power operates Plant Scherer Unit 3 and Gulf Power reimburses Georgia Power for its 25% proportionate share of the related non-fuel expenses, which totaled $8 million in 2018. Gulf Power also owns a 50% portion of Plant Daniel Units 1 and 2. Mississippi Power operates Plant Daniel and Gulf Power reimburses Mississippi Power for its proportionate share of all associated non-fuel operations and maintenance expenses, which totaled $31 million in 2018. See Note 5 under "Joint Ownership Agreements" and Note 15 under "Southern Company" and "Alabama Power" for additional information. Alabama Power and Georgia Power each have agreements with PowerSecure for equipment purchases and/or services related to utility infrastructure construction, distributed energy, and energy efficiency projects. Alabama Power's costs for these services were immaterial for 2020 and totaled $7 million and $24 million in 2019 and 2018, respectively. Georgia Power's costs for these equipment purchases and services totaled approximately $11 million in 2020 and were immaterial for the other periods presented. See Note 7 under "SEGCO" for information regarding Alabama Power's and Georgia Power's equity method investment in SEGCO and related affiliate purchased power costs, as well as Alabama Power's gas pipeline ownership agreement with SEGCO. Southern Power has several agreements with SCS for transmission services, which are billed to Southern Power based on the Southern Company Open Access Transmission Tariff as filed with the FERC. Transmission services purchased by Southern Power from SCS totaled $15 million, $15 million, and $12 million for 2020, 2019, and 2018, respectively, and were charged to other operations and maintenance expenses in Southern Power's consolidated statements of income. The traditional electric operating companies and Southern Power may jointly enter into various types of wholesale energy, natural gas, and certain other contracts, either directly or through SCS as agent. Each participating company may be jointly and severally liable for the obligations incurred under these agreements. See Note 14 under "Contingent Features" for additional information. Southern Power and the traditional electric operating companies generally settle amounts related to the above transactions on a monthly basis in the month following the performance of such services or the purchase or sale of electricity. See "Revenues – Southern Power" herein for additional information. The traditional electric operating companies, Southern Power, and Southern Company Gas provide incidental services to and receive such services from other Southern Company subsidiaries which are generally minor in duration and amount. Except as described herein, the traditional electric operating companies, Southern Power, and Southern Company Gas neither provided nor received any material services to or from affiliates in any year presented. Regulatory Assets and Liabilities The traditional electric operating companies and the natural gas distribution utilities are subject to accounting requirements for the effects of rate regulation. Regulatory assets represent probable future revenues associated with certain costs that are expected to be recovered from customers through the ratemaking process. Regulatory liabilities represent costs recovered that are expected to be incurred in the future or probable future reductions in revenues associated with amounts that are expected to be credited to customers through the ratemaking process. In the event that a portion of a traditional electric operating company's or a natural gas distribution utility's operations is no longer subject to applicable accounting rules for rate regulation, such company would be required to write off to income or reclassify to AOCI related regulatory assets and liabilities that are not specifically recoverable through regulated rates. In addition, the traditional electric operating company or the natural gas distribution utility would be required to determine if any impairment to other assets, including plant, exists and write down the assets, if impaired, to their fair values. All regulatory assets and liabilities are to be reflected in rates. See Note 2 for additional information including details of regulatory assets and liabilities reflected in the balance sheets for Southern Company, the traditional electric operating companies, and Southern Company Gas. Revenues The Registrants generate revenues from a variety of sources which are accounted for under various revenue accounting guidance, including revenue from contracts with customers, lease, derivative, and regulatory accounting. See Notes 4, 9, and 14 for additional information. Traditional Electric Operating Companies The majority of the revenues of the traditional electric operating companies are generated from contracts with retail electric customers. These revenues, generated from the integrated service to deliver electricity when and if called upon by the customer, are recognized as a single performance obligation satisfied over time, at a tariff rate, and as electricity is delivered to the customer during the month. Unbilled revenues related to retail sales are accrued at the end of each fiscal period. Retail rates may include provisions to adjust revenues for fluctuations in fuel costs, fuel hedging, the energy component of purchased power costs, and certain other costs. Revenues are adjusted for differences between these actual costs and amounts billed in current regulated rates. Under or over recovered regulatory clause revenues are recorded in the balance sheets and are recovered from or returned to customers, respectively, through adjustments to the billing factors. See Note 2 for additional information regarding regulatory matters of the traditional electric operating companies. Wholesale capacity revenues from PPAs are recognized in amounts billable under the contract terms. Energy and other revenues are generally recognized as services are provided. The contracts for capacity and energy in a wholesale PPA have multiple performance obligations where the contract's total transaction price is allocated to each performance obligation based on the standalone selling price. The standalone selling price is primarily determined by the price charged to customers for the specific goods or services transferred with the performance obligations. Generally, the traditional electric operating companies recognize revenue as the performance obligations are satisfied over time as electricity is delivered to the customer or as generation capacity is available to the customer. For both retail and wholesale revenues, the traditional electric operating companies have elected to recognize revenue for their sales of electricity and capacity using the invoice practical expedient as they generally have a right to consideration in an amount that corresponds directly with the value to the customer of the performance completed to date and that may be invoiced. Payment for goods and services rendered is typically due in the subsequent month following satisfaction of the Registrants' performance obligation. Southern Power Southern Power sells capacity and energy at rates specified under contractual terms in long-term PPAs. These PPAs are accounted for as operating leases, non-derivatives, or normal sale derivatives. Capacity revenues from PPAs classified as operating leases are recognized on a straight-line basis over the term of the agreement. Energy revenues are recognized in the period the energy is delivered. Southern Power's non-lease contracts commonly include capacity and energy which are considered separate performance obligations. In these contracts, the total transaction price is allocated to each performance obligation based on the standalone selling price. The standalone selling price is primarily determined by the price charged to customers for the specific goods or services transferred with the performance obligations. Generally, Southern Power recognizes revenue as the performance obligations are satisfied over time, as electricity is delivered to the customer or as generation capacity is made available to the customer. Southern Power generally has a right to consideration in an amount that corresponds directly with the value to the customer of the performance completed to date and may recognize revenue in the amount to which the entity has a right to invoice. Payment for goods and services rendered is typically due in the subsequent month following satisfaction of Southern Power's performance obligation. When multiple contracts exist with the same counterparty, the revenues from each contract are accounted for as separate arrangements. Southern Power may also enter into contracts to sell short-term capacity in the wholesale electricity markets. These sales are generally classified as mark-to-market derivatives and net unrealized gains and losses on such contracts are recorded in wholesale revenues. See Note 14 and "Financial Instruments" herein for additional information. Southern Company Gas Gas Distribution Operations Southern Company Gas records revenues when goods or services are provided to customers. Those revenues are based on rates approved by the state regulatory agencies of the natural gas distribution utilities. Atlanta Gas Light operates in a deregulated natural gas market wher eby M arketers, rather than a traditional utility, sell natural gas to end-use customers in Georgia and handle customer billing functions. As required by the Georgia PSC, Atlanta Gas Light bills Marketers in equal monthly installments for each residential, commercial, and industrial end-use customer's distribution costs as well as for capacity costs utilizing a seasonal rate design for the calculation of each residential end-use customer's annual straight-fixed-variable charge, which reflects the historic volumetric usage pattern for the entire residential class. The majority of the revenues of Southern Company Gas are generated from contracts with natural gas distribution customers. Revenues from this integrated service to deliver gas when and if called upon by the customer are recognized as a single performance obligation satisfied over time and are recognized at a tariff rate as gas is delivered to the customer during the month. The standalone selling price is primarily determined by the price charged to customers for the specific goods or services transferred with the performance obligations. Generally, Southern Company Gas recognizes revenue as the performance obligations are satisfied over time as natural gas is delivered to the customer. The performance obligations related to wholesale gas services are satisfied, and revenue is recognized, at a point in time when natural gas is delivered to the customer. Southern Company Gas has elected to recognize revenue for sales of gas using the invoice practical expedient as it generally has a right to consideration in an amount that corresponds directly with the value to the customer of the performance completed to date and that may be invoiced. Payment for goods and services rendered is typically due in the subsequent month following satisfaction of Southern Company Gas' performance obligation. With the exception of Atlanta Gas Light, the natural gas distribution utilities have rate structures that include volumetric rate designs that allow the opportunity to recover certain costs based on gas usage. Revenues from sales and transportation services are recognized in the same period in which the related volumes are delivered to customers. Revenues from residential and certain commercial and industrial customers are recognized on the basis of scheduled meter readings. Additionally, unbilled revenues are recognized for estimated deliveries of gas not yet billed to these customers, from the last bill date to the end of the accounting period. For other commercial and industrial customers and for all wholesale customers, revenues are based on actual deliveries through the end of the period. The tariffs for several of the natural gas distribution utilities include provisions which allow for the recognition of certain revenues prior to the time such revenues are billed to customers. These provisions are referred to as alternative revenue programs and provide for the recognition of certain revenues prior to billing, as long as the amounts recognized will be collected from customers within 24 months of recognition. These programs are as follows: • Weather normalization adjustments – reduce customer bills when winter weather is colder than normal and increase customer bills when weather is warmer than normal and are included in the tariffs for Virginia Natural Gas, Chattanooga Gas, and, prior to its sale, Elizabethtown Gas; • Revenue normalization mechanisms – mitigate the impact of conservation and declining customer usage and are contained in the tariffs for Virginia Natural Gas, Chattanooga Gas, Nicor Gas (effective November 1, 2019), and, prior to its sale, Elkton Gas; and • Revenue true-up adjustment – included within the provisions of the GRAM program in which Atlanta Gas Light participates as a short-term alternative to formal rate case filings, the revenue true-up feature provides for a positive (or negative) adjustment to record revenue in the amount of any variance to budgeted revenues, which are submitted and approved annually as a requirement of GRAM. Such adjustments are reflected in customer billings in a subsequent program year. Wholesale Gas Services Southern Company Gas nets revenues from energy and risk management activities with the associated costs. Profits from sales between segments are eliminated and are recognized as goods or services sold to end-use customers. Southern Company Gas records transactions that qualify as derivatives at fair value with changes in fair value recognized in earnings in the period of change and characterized as unrealized gains or losses. Gains and losses on derivatives held for energy trading purposes are presented on a net basis in revenue. Gas Marketing Services Southern Company Gas recognizes revenues from natural gas sales and transportation services in the same period in which the related volumes are delivered to customers and recognizes sales revenues from residential and certain commercial and industrial customers on the basis of scheduled meter readings. Southern Company Gas also recognizes unbilled revenues for estimated deliveries of gas not yet billed to these customers from the most recent meter reading date to the end of the accounting period. For other commercial and industrial customers and for all wholesale customers, revenues are based on actual deliveries during the period. Southern Company Gas recognizes revenues on 12-month utility-bill management contracts as the lesser of cumulative earned or cumulative billed amounts. Concentration of Credit Risk Southern Company Gas' wholesale gas services business has a concentration of credit risk for services it provides to its counterparties. This credit risk is generally concentrated in 20 of its counterparties and is measured by 30-day receivable exposure plus forward exposure. Counterparty credit risk is evaluated using a S&P equivalent credit rating, which is determined by a process of converting the lower of the S&P or Moody's rating to an internal rating ranging from 9 to 1, with 9 being equivalent to AAA/Aaa by S&P and Moody's, respectively, and 1 being equivalent to D/Default by S&P and Moody's, respectively. A counterparty that does not have an external rating is assigned an internal rating based on the strength of its financial ratios. As of December 31, 2020, the top 20 counterparties represented 58%, or $234 million , of the total counterparty exposure and had a weighted average S&P equivalent rating of A-. Concentration of credit risk occurs at Atlanta Gas Light for amounts billed for services and other costs to its customers, which consist of 16 Marketers in Georgia (including SouthStar). The credit risk exposure to the Marketers varies seasonally, with the lowest exposure in the non-peak summer months and the highest exposure in the peak winter months. Marketers are responsible for the retail sale of natural gas to end-use customers in Georgia. The functions of the retail sale of gas include the purchase and sale of natural gas, customer service, billings, and collections. The provisions of Atlanta Gas Light's tariff allow Atlanta Gas Light to obtain credit security support in an amount equal to a minimum of two times a Marketer's highest month's estimated bill from Atlanta Gas Light. Concentration of Revenue Southern Company, Alabama Power, Georgia Power, Mississippi Power (with the exception of its full requirements cost-based MRA electric tariffs described below), and Southern Company Gas each have a diversified base of customers and no single customer or industry comprises 10% or more of each company's revenues. Mississippi Power provides service under long-term contracts with rural electric cooperative associations and a municipality located in southeastern Mississippi under full requirements cost-based MRA electric tariffs, which are subject to regulation by the FERC. The contracts with these wholesale customers represent ed 15.3% of Mississippi Power 's total operating revenues in 2020 and are generally subject to 10 -year rolling c ancellation notices. Historically, these wholesale customers have acted as a group and any changes in contractual relationships for one customer are likely to be followed by the other wholesale customers. Significant portions of Southern Power's revenues have been derived from certain customers pursuant to PPAs. The following table shows the percentage of total revenues for Southern Power's top three customers for each of the years presented: 2020 2019 2018 Southern California Edison 9.4 % 6.8 % 6.2 % Georgia Power 8.0 % 9.0 % 9.8 % Duke Energy Corporation 6.7 % N/A 6.8 % Morgan Stanley Capital Group N/A 4.9 % N/A Fuel Costs Fuel costs for the traditional electric operating companies and Southern Power are expensed as the fuel is used. Fuel expense generally includes fuel transportation costs and the cost of purchased emissions allowances as they are used. For Alabama Power and Georgia Power, fuel expense also includes the amortization of the cost of nuclear fuel. For the traditional electric operating companies, fuel costs also include gains and/or losses from fuel-hedging programs as approved by their respective state PSCs. Cost of Natural Gas Excluding Atlanta Gas Light, which does not sell natural gas to end-use customers, Southern Company Gas charges its utility customers for natural gas consumed using natural gas cost recovery mechanisms set by the applicable state regulatory agencies. Under these mechanisms, all prudently-incurred natural gas costs are passed through to customers without markup, subject to regulatory review. Southern Company Gas defers or accrues the difference between the actual cost of natural gas and the amount of commodity revenue earned in a given period such that no operating income is recognized related to these costs. The deferred or accrued amount is either billed or refunded to customers prospectively through adjustments to the commodity rate. Deferred and accrued natural gas costs are included in the balance sheets as regulatory assets and regulatory liabilities, respectively. Southern Company Gas' gas marketing services' customers are charged for actual or estimated natural gas consumed. Within cost of natural gas, Southern Company Gas also includes costs of lost and unaccounted for gas, adjustments to reduce the value of inventories to market value, and gains and losses associated with certain derivatives. Income Taxes The Registrants use the liability method of accounting for deferred income taxes and provide deferred income taxes for all significant income tax temporary differences. In accordance with regulatory requirements, deferred federal ITCs for the traditional electric operating companies are deferred and amortized over the average life of the related property, with such amortization normally applied as a credit to reduce depreciation and amortization in the statements of income. Southern Power's and the natural gas distribution utilities' deferred federal ITCs, as well as certain state ITCs for Nicor Gas, are deferred and amortized to income tax expense over the life of the respective asset. Under current tax law, certain projects at Southern Power related to the construction of renewable facilities are eligible for federal ITCs. Southern Power estimates eligible costs which, as they relate to acquisitions, may not be finalized until the allocation of the purchase price to assets has been finalized. Southern Power applies the deferred method to ITCs, whereby the ITCs are recorded as a deferred credit and amortized t |
REGULATORY MATTERS
REGULATORY MATTERS | 12 Months Ended |
Dec. 31, 2020 | |
Regulated Operations [Abstract] | |
REGULATORY MATTERS | REGULATORY MATTERS Regulatory Assets and Liabilities Details of regulatory assets and (liabilities) reflected in the balance sheets at December 31, 2020 and 2019 are provided in the following tables: Southern Company Alabama Power Georgia Power Mississippi Power Southern Company Gas (in millions) At December 31, 2020 AROs (a)(s) $ 5,147 $ 1,470 $ 3,457 $ 212 $ — Retiree benefit plans (b)(s) 4,958 1,265 1,647 238 187 Remaining net book value of retired assets (c) 1,183 632 527 24 — Deferred income tax charges (d) 801 235 531 32 — Environmental remediation (e)(s) 310 — 41 — 269 Loss on reacquired debt (f) 304 47 248 6 3 Storm damage (g) 262 — 262 — — Vacation pay (h)(s) 207 80 104 10 13 Under recovered regulatory clause revenues (i) 185 58 — 52 75 Regulatory clauses (j) 142 142 — — — Nuclear outage (k) 101 61 40 — — Long-term debt fair value adjustment (l) 92 — — — 92 Kemper County energy facility assets, net (m) 50 — — 50 — Plant Daniel Units 3 and 4 (n) 32 — — 32 — Other regulatory assets (o) 205 52 68 4 81 Deferred income tax credits (d) (6,016) (2,016) (2,805) (320) (847) Other cost of removal obligations (a) (1,999) (335) 212 (194) (1,649) Over recovered regulatory clause revenues (i) (185) (46) (44) — (95) Storm/property damage reserves (p) (81) (77) — (4) — Customer refunds (q) (56) (50) (6) — — Other regulatory liabilities (r) (149) (37) (30) (6) (54) Total regulatory assets (liabilities), net $ 5,493 $ 1,481 $ 4,252 $ 136 $ (1,925) Southern Company Alabama Power Georgia Power Mississippi Power Southern Company Gas (in millions) At December 31, 2019 Retiree benefit plans (b)(s) $ 4,423 $ 1,131 $ 1,516 $ 213 $ 167 AROs (a)(s) 4,381 1,043 3,119 210 — Remaining net book value of retired assets (c) 1,275 649 596 30 — Deferred income tax charges (d) 803 245 523 33 — Storm damage (g) 410 — 410 — — Environmental remediation (e)(s) 349 — 52 — 296 Loss on reacquired debt (f) 323 52 262 6 4 Vacation pay (h)(s) 186 72 93 9 11 Under recovered regulatory clause revenues (i) 159 40 — 47 72 Regulatory clauses (j) 142 142 — — — Long-term debt fair value adjustment (l) 107 — — — 107 Nuclear outage (k) 105 78 27 — — Fuel-hedging (realized and unrealized) losses (t) 102 22 53 27 — Kemper County energy facility assets, net (m) 61 — — 61 — Plant Daniel Units 3 and 4 (n) 34 — — 34 — Other regulatory assets (o) 127 45 23 6 53 Deferred income tax credits (d) (6,301) (1,960) (3,078) (358) (874) Other cost of removal obligations (a) (2,084) (412) 156 (189) (1,606) Customer refunds (q) (285) (56) (229) — — Over recovered regulatory clause revenues (i) (205) (112) (10) — (82) Storm/property damage reserves (p) (204) (150) — (55) — Other regulatory liabilities (r) (70) (19) (6) (10) (22) Total regulatory assets (liabilities), net $ 3,838 $ 810 $ 3,507 $ 64 $ (1,874) Unless otherwise noted, the following recovery and amortization periods for these regulatory assets and (liabilities) have been approved by the respective state PSC or regulatory agency: (a) AROs and other cost of removal obligations generally are recorded over the related property lives, which may range up to 53 years for Alabama Power, 60 years for Georgia Power, 55 years for Mississippi Power, and 80 years for Southern Company Gas. AROs and cost of removal obligations will be settled and trued up following completion of the related activities. Effective January 1, 2020, Georgia Power is recovering CCR AROs, including past under recovered costs and estimated annual compliance costs, over three-year periods ending December 31, 2022, 2023, and 2024 through its Environmental Compliance Cost Recovery (ECCR) tariff, as discussed further under "Georgia Power – Rate Plans" herein. See Note 6 for additional information on AROs. (b) Recovered and amortized over the average remaining service period, which may range up to 13 years for Alabama Power, 13 years for Georgia Power, 14 years for Mississippi Power, and 13 years for Southern Company Gas. Southern Company's balances also include amounts at SCS and Southern Nuclear that are allocated to the applicable regulated utilities. See Note 11 for additional information. (c) Alabama Power : Primarily represents the net book value of Plant Gorgas Units 8, 9, and 10 ($585 million at December 31, 2020). Being amortized over remaining periods not exceeding 17 years (through 2037). Georgia Power : Net book values of Plant Hammond Units 1 through 4 and Plant Branch Units 2 through 4 (totaling $503 million at December 31, 2020) are being amortized over remaining periods of between two Mississippi Power : Represents net book value associated with Plant Watson and Plant Greene County. The retail and wholesale portions totaling approximately $11 million and $13 million at December 31, 2020, respectively, are being amortized over a four-year period through 2024 and a 10-year period through 2030, respectively. See "Mississippi Power – Environmental Compliance Overview Plan" herein for additional information. (d) Deferred income tax charges are recovered and deferred income tax credits are amortized over the related property lives, which may range up to 53 years for Alabama Power, 60 years for Georgia Power, 55 years for Mississippi Power, and 80 years for Southern Company Gas. See Note 10 for additional information. Included in the deferred income tax charges are amounts ($8 million, $9 million, and $1 million for Alabama Power, Georgia Power, and Mississippi Power, respectively, at December 31, 2020) for the retiree Medicare drug subsidy, which are being recovered and amortized through 2027, 2022, and 2024 for Alabama Power, Georgia Power, and Mississippi Power, respectively. As a result of the Tax Reform Legislation, these accounts include certain deferred income tax assets and liabilities not subject to normalization, as described further below: Alabama Power: Related amounts are being recovered and amortized ratably over the related property lives. Georgia Power: Related amounts at December 31, 2020 include $145 million of deferred income tax assets related to CWIP for Plant Vogtle Units 3 and 4 and approximately $440 million of deferred income tax liabilities. The recovery of deferred income tax assets related to CWIP for Plant Vogtle Units 3 and 4 is expected to be determined in a future regulatory proceeding. Effective January 1, 2020, the deferred income tax liabilities are being amortized through 2022. Mississippi Power: Related amounts at December 31, 2020 include $74 million of deferred income tax liabilities, consisting of the retail portion of $66 million being amortized over three years (through 2023) and the wholesale portion of $9 million being amortized over two years (through 2021). See "Mississippi Power – 2019 Base Rate Case" and " – Municipal and Rural Associations Tariff" herein for additional information. Southern Company Gas : Related amounts at December 31, 2020 include $8 million of deferred income tax liabilities, which are being amortized through 2024. See "Southern Company Gas – Rate Proceedings" herein for additional information. (e) Georgia Power is recovering $12 million annually for environmental remediation. Southern Company Gas' costs are recovered through environmental cost recovery mechanisms when the remediation work is performed. See Note 3 under "Environmental Remediation" for additional information. (f) Recovered over either the remaining life of the original issue or, if refinanced, over the remaining life of the new issue. At December 31, 2020, the remaining amortization periods do not exceed 28 years for Alabama Power, 32 years for Georgia Power, eight years for Mississippi Power, and seven years for Southern Company Gas. (g) Georgia Power is recovering approximately $213 million annually for storm damage. See "Georgia Power – Storm Damage Recovery" herein and Note 1 under "Storm Damage Reserves" for additional information. (h) Recorded as earned by employees and recovered as paid, generally within one year. Includes both vacation and banked holiday pay, if applicable. (i) Alabama Power : Balances are recorded monthly and expected to be recovered or returned within nine years. Recovery periods could change based on several factors including changes in cost estimates, load forecasts, and timing of rate adjustments. See "Alabama Power – Rate CNP PPA," " – Rate CNP Compliance," and " – Rate ECR" herein for additional information. Georgia Power : Balances are recorded monthly and expected to be recovered or returned within two years. See "Georgia Power – Rate Plans" herein for additional information. Mississippi Power : At December 31, 2020, $37 million is being amortized over a four-yea Southern Company Gas : Balances are recorded and recovered or amortized over periods generally not exceeding five years. In addition to natural gas cost recovery mechanisms, the natural gas distribution utilities have various other cost recovery mechanisms for the recovery of costs, including those related to infrastructure replacement programs. (j) Will be amortized concurrently with the effective date of Alabama Power's next depreciation study, which is expected to occur no later than 2023. (k) Nuclear outage costs are deferred to a regulatory asset when incurred and amortized over a subsequent period of 18 months for Alabama Power and up to 24 months for Georgia Power. See Note 5 for additional information. (l) Recovered over the remaining lives of the original debt issuances at acquisition, which range up to 18 years at December 31, 2020. (m) Includes $62 million of regulatory assets and $12 million of regulatory liabilities at December 31, 2020. The retail portion includes $50 million of regulatory assets and $12 million of regulatory liabilities that are expected to be fully amortized by 2024 and 2023, respectively. The wholesale portion includes $12 million of regulatory assets that are expected to be fully amortized by 2029. See Note 3 under "Mississippi Power – Other Matters – Kemper County Energy Facility" for additional information. (n) Represents the difference between Mississippi Power's revenue requirement for Plant Daniel Units 3 and 4 under purchase accounting and operating lease accounting, which is expected to be amortized over a period to be determined in future retail and wholesale rate filings. (o) Except as otherwise noted, comprised of numerous immaterial components with remaining amortization periods generally not exceeding 23 years for Alabama Power, three years for Georgia Power, four years for Mississippi Power, and 20 years for Southern Company Gas at December 31, 2020. Balances at December 31, 2020 include deferred COVID-19 costs (except for Alabama Power), as discussed further under "Deferral of Incremental COVID-19 Costs" for each applicable Registrant herein. Balances for Georgia Power also include certain operations and maintenance costs associated with software and cloud computing projects for which the recovery period will be determined in its next base rate case. (p) Amortized as related expenses are incurred. See "Alabama Power – Rate NDR" and "Mississippi Power – System Restoration Rider" herein for additional information. (q) Primarily includes approximately $50 million and $53 million at December 31, 2020 and 2019, respectively, for Alabama Power and $110 million at December 31, 2019 for Georgia Power as a result of each company exceeding its allowed retail return range. Georgia Power's December 31, 2019 balance also includes approximately $105 million pursuant to the Georgia Power Tax Reform Settlement Agreement. Georgia Power's balances also include immaterial amounts related to refunds for transmission service customers. See "Alabama Power" and "Georgia Power – Rate Plans" herein for additional information. (r) Comprised of numerous immaterial components with remaining amortization periods generally not exceeding 17 years for Alabama Power, 12 years for Georgia Power, three years for Mississippi Power, and 20 years for Southern Company Gas at December 31, 2020. (s) Generally not earning a return as they are excluded from rate base or are offset in rate base by a corresponding asset or liability. (t) Fuel-hedging assets and liabilities are recorded over the life of the underlying hedged purchase contracts. Upon final settlement, actual costs incurred are recovered through the applicable traditional electric operating company's fuel cost recovery mechanism. Purchase contracts generally do not exceed three and a half years for Alabama Power, three years for Georgia Power, and five years for Mississippi Power. Immaterial amounts at December 31, 2020 are included in other regulatory assets and liabilities. Alabama Power Alabama Power's revenues from regulated retail operations are collected through various rate mechanisms subject to the oversight of the Alabama PSC. Alabama Power currently recovers its costs from the regulated retail business primarily through Rate RSE, Rate CNP, Rate ECR, and Rate NDR. In addition, the Alabama PSC issues accounting orders to address current events impacting Alabama Power. Petition for Certificate of Convenience and Necessity On August 14, 2020, the Alabama PSC issued its order regarding Alabama Power's September 2019 petition for a CCN, which authorized Alabama Power to (i) construct an approximately 720-MW combined cycle facility at Alabama Power's Plant Barry (Plant Barry Unit 8) that is expected to be placed in service by the end of 2023, (ii) complete the acquisition of the Central Alabama Generating Station, which occurred on August 31, 2020, (iii) purchase approximately 240 MWs of combined cycle generation under a long-term PPA, which began on September 1, 2020, and (iv) pursue up to approximately 200 MWs of cost-effective demand-side management and distributed energy resource programs. Alabama Power's petition for a CCN was predicated on the results of Alabama Power's 2019 IRP provided to the Alabama PSC, which identified an approximately 2,400-MW resource need for Alabama Power, driven by the need for additional winter reserve capacity. See Note 15 under "Alabama Power" for additional information on the acquisition of the Central Alabama Generating Station. The Alabama PSC authorized the recovery of actual costs for the construction of Plant Barry Unit 8 up to 5% above the estimated in-service cost of $652 million. In so doing, it recognized the potential for developments that could cause the project costs to exceed the capped amount, in which case Alabama Power would provide documentation to the Alabama PSC to explain and justify potential recovery of the additional costs. At December 31, 2020, project expenditures associated with Plant Barry Unit 8 included in CWIP totaled approximately $66 million. The Alabama PSC further directed that the proposed solar generation of approximately 400 MWs, coupled with battery energy storage systems (solar/battery systems), be evaluated under an existing Renewable Generation Certificate (RGC) issued by the Alabama PSC in September 2015. The contracts proposed in the CCN petition expired on July 31, 2020. Any future requests for solar/battery systems will be evaluated under the RGC process. Energy Alabama, Gasp, Inc., and the Sierra Club filed requests for reconsideration and rehearing with the Alabama PSC, and, on December 10, 2020, the Alabama PSC issued an order denying the requests. On January 7, 2021, Energy Alabama and Gasp, Inc. filed judicial appeals regarding both the Alabama PSC's August 14, 2020 CCN order and the December 10, 2020 order denying reconsideration and rehearing. Alabama Power expects to recover costs associated with Plant Barry Unit 8 pursuant to its Rate CNP New Plant. Alabama Power is recovering all costs associated with the Central Alabama Generating Station through the inclusion in Rate RSE of revenues from the existing power sales agreement and, on expiration of that agreement, expects to recover costs pursuant to Rate CNP New Plant. The recovery of costs associated with laws, regulations, and other such mandates directed at the utility industry are expected to be recovered through Rate CNP Compliance. Alabama Power expects to recover the capacity-related costs associated with the PPAs through its Rate CNP PPA. In addition, fuel and energy-related costs are expected to be recovered through Rate ECR. Any remaining costs associated with Plant Barry Unit 8 and the acquisition of the Central Alabama Generating Station are expected to be recovered through Rate RSE. The ultimate outcome of these matters cannot be determined at this time. Rate RSE The Alabama PSC has adopted Rate RSE that provides for periodic annual adjustments based upon Alabama Power's projected weighted common equity return (WCER) compared to an allowable range. Rate RSE adjustments are based on forward-looking information for the applicable upcoming calendar year. Rate RSE adjustments for any two-year period, when averaged together, cannot exceed 4.0% and any annual adjustment is limited to 5.0%. When the projected WCER is under the allowed range, there is an adjusting point of 5.98% and eligibility for a performance-based adder of seven basis points, or 0.07%, to the WCER adjusting point if Alabama Power (i) has an "A" credit rating equivalent with at least one of the recognized rating agencies or (ii) is in the top one-third of a designated customer value benchmark survey. As initially designed, if Alabama Power's actual retail return was above the allowed WCER range, the excess would be refunded to customers unless otherwise directed by the Alabama PSC; however, there was no provision for additional customer billings should the actual retail return fall below the WCER range. In 2018, the Alabama PSC approved modifications to Rate RSE and other commitments designed to position Alabama Power to address the growing pressure on its credit quality resulting from the Tax Reform Legislation, without increasing retail rates under Rate RSE in the near term. Alabama Power continues to reduce growth in total debt by increasing equity, with corresponding reductions in debt issuances, thereby de-leveraging its capital structure. Alabama Power's goal is to achieve an equity ratio of approximately 55% by the end of 2025. At December 31, 2020 and 2019, Alabama Power's equity ratio was approximately 51.6% and 50.3%, respectively. The approved modifications to Rate RSE began for billings in January 2019. The modifications include reducing the top of the allowed WCER range from 6.21% to 6.15% and modifications to the refund mechanism applicable to prior year actual results that allow Alabama Power to retain a portion of the revenue that causes the actual WCER for a given year to exceed the allowed range. Generally, during a year without a Rate RSE upward adjustment, if Alabama Power's actual WCER is between 6.15% and 7.65%, customers will receive 25% of the amount between 6.15% and 6.65%, 40% of the amount between 6.65% and 7.15%, and 75% of the amount between 7.15% and 7.65%. Customers will receive all amounts in excess of an actual WCER of 7.65%. During a year with a Rate RSE upward adjustment, if Alabama Power's actual WCER exceeds 6.15%, customers receive 50% of the amount between 6.15% and 6.90% and all amounts in excess of an actual WCER of 6.90%. There is no provision for additional customer billings should the actual retail return fall below the WCER range. In conjunction with these modifications to Rate RSE, in 2018, Alabama Power consented to a moratorium on any upward adjustments under Rate RSE for 2019 and 2020 and to return $50 million to customers through bill credits in 2019. Retail rates under Rate RSE remained unchanged for 2019 and 2020. Together with Rate RSE, Alabama Power has an established retail tariff that provides for an adjustment to customer billings to recognize the impact of a change in the statutory income tax rate. In accordance with this tariff, Alabama Power returned $267 million to retail customers through bill credits during 2018 as a result of the change in the federal income tax rate under the Tax Reform Legislation. At December 31, 2018, Alabama Power's retail return exceeded the allowed WCER range, which resulted in Alabama Power establishing a regulatory liability of $109 million for Rate RSE refunds. In accordance with an Alabama PSC order issued in February 2019, Alabama Power applied $78 million to reduce the Rate ECR under recovered balance and the remaining $31 million was refunded to customers through bill credits starting in July 2019. At December 31, 2019 and 2020, Alabama Power's WCER exceeded 6.15%, resulting in Alabama Power establishing a current regulatory liability of $53 million and $50 million, respectively, for Rate RSE refunds. In April 2020, the regulatory liability at December 31, 2019 was refunded to customers through bill credits. The $50 million regulatory liability at December 31, 2020 will be refunded to customers through bill credits in April 2021. During 2019, Alabama Power provided to the Alabama PSC and the Alabama Office of the Attorney General information related to the operation and utilization of Rate RSE, in accordance with the rules governing the operation of Rate RSE. During 2020, the Alabama PSC concluded that Rate RSE continues to fulfill its intended purposes and that no significant revisions are needed or warranted. On December 1, 2020, Alabama Power made its required annual Rate RSE submission to the Alabama PSC of projected data for calendar year 2021, resulting in an increase of 4.09%, or approximately $228 million annually, that became effective for the billing month of January 2021. Rate CNP New Plant Rate CNP New Plant allows for recovery of Alabama Power's retail costs associated with newly developed or acquired certificated generating facilities placed into retail service. No adjustments to Rate CNP New Plant occurred during the period 2018 through 2020. See "Petition for Certificate of Convenience and Necessity" herein for additional information. Rate CNP PPA Rate CNP PPA allows for the recovery of Alabama Power's retail costs associated with certificated PPAs. Revenues for Rate CNP PPA, as recorded on the financial statements, are adjusted for differences in actual recoverable costs and amounts billed in current regulated rates. Accordingly, changes in the billing factor will have no significant effect on Southern Company's or Alabama Power's revenues or net income but will affect annual cash flow. No adjustments to Rate CNP PPA occurred during the period 2018 through 2020 and no adjustment is expected for 2021. At December 31, 2020 and 2019, Alabama Power had an under recovered Rate CNP PPA balance of $58 million and $40 million, respectively, which is included in other regulatory assets, deferred on the balance sheet. Rate CNP Compliance Rate CNP Compliance allows for the recovery of Alabama Power's retail costs associated with laws, regulations, and other such mandates directed at the utility industry involving the environment, security, reliability, safety, sustainability, or similar considerations impacting Alabama Power's facilities or operations. Rate CNP Compliance is based on forward-looking information and provides for the recovery of these costs pursuant to factors that are calculated and submitted to the Alabama PSC by December 1 with rates effective for the following calendar year. Compliance costs to be recovered include operations and maintenance expenses, depreciation, and a return on certain invested capital. Revenues for Rate CNP Compliance, as recorded on the financial statements, are adjusted for differences in actual recoverable costs and amounts billed in current regulated rates. Accordingly, changes in the billing factor will have no significant effect on Southern Company's or Alabama Power's revenues or net income, but will affect annual cash flow. Changes in Rate CNP Compliance-related operations and maintenance expenses and depreciation generally will have no effect on net income. In November 2018, 2019, and 2020, Alabama Power submitted calculations associated with its cost of complying with governmental mandates for the following calendar year, as provided under Rate CNP Compliance. The 2018 filing reflected a projected under recovered retail revenue requirement of approximately $205 million, which was recovered in the billing months of January 2019 through December 2019. The 2019 filing reflected a projected over recovered retail revenue requirement, which resulted in a rate decrease of approximately $68 million that became effective for the billing month of January 2020. The 2020 filing reflected a projected under recovered retail revenue requirement of approximately $59 million. On December 1, 2020, the Alabama PSC issued a consent order that Alabama Power leave the 2020 Rate CNP Compliance factor in effect for 2021, with any prior year under collected amount deemed recovered before any current year amounts are recovered. Any remaining under recovered amount will be reflected in the 2021 filing. At December 31, 2020, Alabama Power had an over recovered Rate CNP Compliance balance of $28 million included in other regulatory liabilities, current on the balance sheet. At December 31, 2019, Alabama Power had an over recovered Rate CNP Compliance balance of $62 million, of which $55 million is included in other regulatory liabilities, current and $7 million is included in other regulatory liabilities, deferred on the balance sheet. Rate ECR Rate ECR recovers Alabama Power's retail energy costs based on an estimate of future energy costs and the current over or under recovered balance. Revenues recognized under Rate ECR and recorded on the financial statements are adjusted for the difference in actual recoverable fuel costs and amounts billed in current regulated rates. The difference in the recoverable fuel costs and amounts billed gives rise to the over or under recovered amounts recorded as regulatory assets or liabilities. Alabama Power, along with the Alabama PSC, continually monitors the over or under recovered cost balance to determine whether an adjustment to billing rates is required. Changes in the Rate ECR factor have no significant effect on Southern Company's or Alabama Power's net income but will impact operating cash flows. The Alabama PSC may approve billing rates under Rate ECR of up to 5.910 cents per KWH. In May 2018, the Alabama PSC approved an increase to Rate ECR from 2.015 cents per KWH to 2.353 cents per KWH effective July 2018 through December 2018. In December 2018, the Alabama PSC issued a consent order to leave this rate in effect through December 31, 2019. As discussed herein under "Rate RSE," in accordance with an Alabama PSC order issued in February 2019, Alabama Power utilized $78 million of the 2018 Rate RSE refund liability to reduce the Rate ECR under recovered balance. In December 2019, the Alabama PSC approved a decrease to Rate ECR from 2.353 cents per KWH to 2.160 cents per KWH, equal to 1.82%, or approximately $102 million annually, that became effective for the billing month of January 2020. In October 2020, Alabama Power reduced its over-collected fuel balance by $94.3 million in accordance with an August 7, 2020 Alabama PSC order authorizing Alabama Power to reduce its over-collected fuel balance by $100 million and return that amount to customers in the form of bill credits, with any undistributed amount remaining in the regulatory liability for the benefit of customers. On December 1, 2020, the Alabama PSC approved a decrease to Rate ECR from 2.160 cents per KWH to 1.960 cents per KWH, equal to 1.84%, or approximately $103 million annually, that became effective for the billing month of January 2021. The rate will adjust to 5.910 cents per KWH in January 2022 absent a further order from the Alabama PSC. At December 31, 2020, Alabama Power's over recovered fuel costs totaled $18 million and is included in other regulatory liabilities, current on the balance sheet. At December 31, 2019, Alabama Power's over recovered fuel costs totaled $49 million, of which $32 million is included in other regulatory liabilities, current and $17 million is included in other regulatory liabilities, deferred on the balance sheet. These classifications are based on estimates, which include such factors as weather, generation availability, energy demand, and the price of energy. A change in any of these factors could have a significant impact on the timing of any recovery or return of fuel costs. Tax Reform Accounting Order In 2018, the Alabama PSC approved an accounting order that authorized Alabama Power to defer the benefits of federal excess deferred income taxes associated with the Tax Reform Legislation for the year ended December 31, 2018 as a regulatory liability and to use up to $30 million of such deferrals to offset under recovered amounts under Rate ECR. The final excess deferred tax liability for the year ended December 31, 2018 totaled approximately $69 million, of which $30 million was used to offset the Rate ECR under recovered balance. In December 2019, the Alabama PSC issued an order authorizing Alabama Power to apply the remaining deferred balance of approximately $39 million to increase the balance in the NDR. See "Rate NDR" herein and Note 10 under "Current and Deferred Income Taxes" for additional information. Software Accounting Order In February 2019, the Alabama PSC approved an accounting order that authorizes Alabama Power to establish a regulatory asset for operations and maintenance costs associated with software implementation projects. The regulatory asset will be amortized ratably over the life of the related software. At December 31, 2020 and 2019, the regulatory asset balance totaled $17 million and $6 million, respectively, and is included in other deferred charges and assets on the balance sheet. Plant Greene County Alabama Power jointly owns Plant Greene County with an affiliate, Mississippi Power. See Note 5 under "Joint Ownership Agreements" for additional information. In December 2019, Mississippi Power updated its proposed RMP, originally filed in 2018 with the Mississippi PSC. The RMP proposed a four-year acceleration of the retirement of Plant Greene County Units 1 and 2 to the third quarter 2021 and the third quarter 2022, respectively. On December 17, 2020, the Mississippi PSC issued an order concluding the RMP docket and requiring Mississippi Power to incorporate into its 2021 IRP a schedule of early or anticipated retirement of 950 MWs of fossil-steam generation, which could include Plant Greene County, by year-end 2027 to reduce Mississippi Power's excess reserve margin. Mississippi Power's IRP is scheduled to be filed in April 2021. Any proposed Plant Greene County unit retirements by Mississippi Power would require the completion of transmission and system reliability improvements, as well as agreement by Alabama Power. Alabama Power will continue to monitor the status of Mississippi Power's IRP and associated regulatory processes, as well as the transmission and system reliability improvements. Alabama Power will review all the facts and circumstances and will evaluate all of its alternatives prior to reaching a final determination on the ongoing operations of Plant Greene County. The ultimate outcome of this matter cannot be determined at this time. Rate NDR Based on an order from the Alabama PSC, Alabama Power maintains a reserve for operations and maintenance expenses to cover the cost of damages from major storms to its transmission and distribution facilities. The order approves a separate monthly Rate NDR charge to customers consisting of two components. The first component is intended to establish and maintain a reserve balance for future storms and is an on-going part of customer billing. When the reserve balance falls below $50 million, a reserve establishment charge will be activated (and the on-going reserve maintenance charge concurrently suspended) until the reserve balance reaches $75 million. The second component of the Rate NDR charge is intended to allow recovery of any existing deferred storm-related operations and maintenance costs and any future reserve deficits over a 24-month period. The Alabama PSC order gives Alabama Power authority to record a deficit balance in the NDR when costs of storm damage exceed any established reserve balance. Absent further Alabama PSC approval, the maximum total Rate NDR charge consisting of both components is $10 per month per non-residential customer account and $5 per month per residential customer account. Alabama Power has the authority, based on an order from the Alabama PSC, to accrue certain additional am |
CONTINGENCIES, COMMITMENTS, AND
CONTINGENCIES, COMMITMENTS, AND GUARANTEES | 12 Months Ended |
Dec. 31, 2020 | |
Commitments and Contingencies Disclosure [Abstract] | |
CONTINGENCIES, COMMITMENTS, AND GUARANTEES | CONTINGENCIES, COMMITMENTS, AND GUARANTEES General Litigation Matters The Registrants are involved in various matters being litigated and regulatory matters. The ultimate outcome of such pending or potential litigation or regulatory matters against each Registrant and any subsidiaries cannot be determined at this time; however, for current proceedings not specifically reported herein, management does not anticipate that the ultimate liabilities, if any, arising from such current proceedings would have a material effect on such Registrant's financial statements. The Registrants believe the pending legal challenges discussed below have no merit; however, the ultimate outcome of these matters cannot be determined at this time. Southern Company In January 2017, a securities class action complaint was filed in the U.S. District Court for the Northern District of Georgia by Monroe County Employees' Retirement System on behalf of all persons who purchased shares of Southern Company's common stock between April 25, 2012 and October 30, 2013, as subsequently amended. The amended complaint named as defendants Southern Company, certain of its current and former officers, and certain former Mississippi Power officers and alleged that the defendants made materially false and misleading statements regarding the Kemper County energy facility in violation of certain provisions under the Securities Exchange Act of 1934, as amended. The complaint sought, among other things, compensatory damages and litigation costs and attorneys' fees. In 2018, the court issued an order dismissing certain claims against certain officers of Southern Company and Mississippi Power and dismissing the allegations related to a number of the statements that plaintiffs challenged as being false or misleading. In 2018, the court denied the defendants' motion for reconsideration and also denied a motion to certify the issue for interlocutory appeal. In 2019, the court certified the plaintiffs' proposed class and entered an order staying all deadlines in the case pending mediation. In the third quarter 2020, the parties reached a settlement and the plaintiffs filed a stipulation of settlement and motion for preliminary approval to resolve the case on a class-wide basis, which the court granted on October 1, 2020. On January 14, 2021, the court granted final approval of the settlement. The settlement amount was paid entirely through existing insurance policies and did not have a material impact on Southern Company's financial statements. This matter is now concluded. In February 2017, Jean Vineyard and Judy Mesirov each filed a shareholder derivative lawsuit in the U.S. District Court for the Northern District of Georgia. Each of these lawsuits names as defendants Southern Company, certain of its directors, certain of its current and former officers, and certain former Mississippi Power officers. In 2017, these two shareholder derivative lawsuits were consolidated in the U.S. District Court for the Northern District of Georgia. The complaints allege that the defendants caused Southern Company to make false or misleading statements regarding the Kemper County energy facility cost and schedule. Further, the complaints allege that the defendants were unjustly enriched and caused the waste of corporate assets and also allege that the individual defendants violated their fiduciary duties. In May 2017, Helen E. Piper Survivor's Trust filed a shareholder derivative lawsuit in the Superior Court of Gwinnett County, Georgia that names as defendants Southern Company, certain of its directors, certain of its current and former officers, and certain former Mississippi Power officers. The complaint alleges that the individual defendants, among other things, breached their fiduciary duties in connection with schedule delays and cost overruns associated with the construction of the Kemper County energy facility. The complaint further alleges that the individual defendants authorized or failed to correct false and misleading statements regarding the Kemper County energy facility schedule and cost and failed to implement necessary internal controls to prevent harm to Southern Company. In August 2019, the court granted a motion filed by the plaintiff in July 2019 to substitute a new named plaintiff, Martin J. Kobuck, in place of Helen E. Piper Survivor's Trust. The plaintiffs in each of these cases seek to recover, on behalf of Southern Company, unspecified actual damages and, on each plaintiff's own behalf, attorneys' fees and costs in bringing the lawsuit, as well as certain changes to Southern Company's corporate governance and internal processes. In 2018, the court in each case entered an order staying each lawsuit until 30 days after the resolution of any dispositive motions or any settlement, whichever is earlier, in the securities class action. In September 2020, the plaintiffs in each case filed a status report noting the settlement of the securities class action and informing the court that the parties had scheduled mediation, which occurred on November 12, 2020. The parties in each case did not reach settlement but continue to explore possible resolution. Each case is stayed while the parties discuss potential resolution. Georgia Power In 2011, plaintiffs filed a putative class action against Georgia Power in the Superior Court of Fulton County, Georgia alleging that Georgia Power's collection in rates of amounts for municipal franchise fees (which fees are paid to municipalities) exceeded the amounts allowed in orders of the Georgia PSC and alleging certain state law claims. This case has been ruled upon and appealed numerous times over the last several years. In one recent appeal, the Georgia Supreme Court remanded the case and noted that the trial court could refer the matter to the Georgia PSC to interpret its tariffs. Following a motion by Georgia Power, in February 2019, the Superior Court of Fulton County ordered the parties to submit petitions to the Georgia PSC for a declaratory ruling and also conditionally certified the proposed class. In March 2019, Georgia Power and the plaintiffs filed petitions with the Georgia PSC seeking confirmation of the proper application of the municipal franchise fee schedule pursuant to the Georgia PSC's orders. Also in March 2019, Georgia Power appealed the class certification decision to the Georgia Court of Appeals. In October 2019, the Georgia PSC issued an order that found Georgia Power has appropriately implemented the municipal franchise fee schedule. On March 11, 2020, the Georgia Court of Appeals vacated the Superior Court of Fulton County's February 2019 order granting conditional class certification and remanded the case to the Superior Court of Fulton County for further proceedings. In September 2020, the plaintiffs and Georgia Power each filed motions for summary judgment and the plaintiffs renewed their motion for class certification. The amount of any possible losses cannot be estimated at this time because, among other factors, it is unknown whether a class will be certified, the ultimate composition of any class, and whether any losses would be subject to recovery from any municipalities. On July 29, 2020, a group of individual plaintiffs filed a complaint in the Superior Court of Fulton County, Georgia against Georgia Power alleging that releases from Plant Scherer have impacted groundwater, surface water, and air, resulting in alleged personal injuries and property damage. The plaintiffs seek an unspecified amount of monetary damages including punitive damages, a medical monitoring fund, and injunctive relief. In September 2020, Georgia Power filed a motion to dismiss. The amount of any possible losses cannot be estimated at this time. Mississippi Power In 2018, Ray C. Turnage and 10 other individual plaintiffs filed a putative class action complaint against Mississippi Power and the three then-serving members of the Mississippi PSC in the U.S. District Court for the Southern District of Mississippi. Mississippi Power received Mississippi PSC approval in 2013 to charge a mirror CWIP rate premised upon including in its rate base pre-construction and construction costs for the Kemper IGCC prior to placing the Kemper IGCC into service. The Mississippi Supreme Court reversed that approval and ordered Mississippi Power to refund the amounts paid by customers under the previously-approved mirror CWIP rate. The plaintiffs allege that the initial approval process, and the amount approved, were improper. They also allege that Mississippi Power underpaid customers by up to $23.5 million in the refund process by applying an incorrect interest rate. The plaintiffs seek to recover, on behalf of themselves and their putative class, actual damages, punitive damages, pre-judgment interest, post-judgment interest, attorney's fees, and costs. In response to Mississippi Power and the Mississippi PSC each filing a motion to dismiss, the plaintiffs filed an amended complaint in March 2019. The amended complaint included four additional plaintiffs and additional claims for gross negligence, reckless conduct, and intentional wrongdoing. Mississippi Power and the Mississippi PSC each filed a motion to dismiss the amended complaint, which occurred on May 26, 2020 and March 27, 2020, respectively. Also on March 27, 2020, the plaintiffs filed a motion seeking to name the new members of the Mississippi PSC, the Mississippi Development Authority, and Southern Company as additional defendants and add a cause of action against all defendants based on a dormant commerce clause theory under the U.S. Constitution. On July 28, 2020, the plaintiffs filed a motion for leave to file a third amended complaint, which included the same federal claims as the proposed second amended complaint, as well as several additional state law claims based on the allegation that Mississippi Power failed to disclose the annual percentage rate of interest applicable to refunds. On November 10, 2020, the court denied each of the plaintiffs' pending motions and entered final judgment in favor of Mississippi Power. On January 22, 2021, the court denied further motions by the plaintiffs to vacate the judgment and to file a revised second amended complaint. An adverse outcome in this proceeding could have a material impact on Mississippi Power's financial statements. See "Other Matters – Mississippi Power – Kemper County Energy Facility" herein for additional information. Environmental Remediation The Southern Company system must comply with environmental laws and regulations governing the handling and disposal of waste and releases of hazardous substances. Under these various laws and regulations, the Southern Company system could incur substantial costs to clean up affected sites. The traditional electric operating companies and the natural gas distribution utilities conduct studies to determine the extent of any required cleanup and have recognized the estimated costs to clean up known impacted sites in the financial statements. A liability for environmental remediation costs is recognized only when a loss is determined to be probable and reasonably estimable and is reduced as expenditures are incurred. The traditional electric operating companies and the natural gas distribution utilities in Illinois and Georgia have each received authority from their respective state PSCs or other applicable state regulatory agencies to recover approved environmental remediation costs through regulatory mechanisms. Any difference between the liabilities accrued and costs recovered through rates is deferred as a regulatory asset or liability. These regulatory mechanisms are adjusted annually or as necessary within limits approved by the state PSCs or other applicable state regulatory agencies. At December 31, 2020 and 2019, Alabama Power did not have environmental remediation liabilities and Mississippi Power's balance was immaterial. Georgia Power has been designated or identified as a potentially responsible party at sites governed by the Georgia Hazardous Site Response Act and/or by the federal Comprehensive Environmental Response, Compensation, and Liability Act, and assessment and potential cleanup of such sites is expected. For 2020, 2019, and 2018, Georgia Power recovered approximately $12 million, $2 million, and $2 million, respectively, through the ECCR tariff for environmental remediation. In December 2019, Mississippi Power entered into an agreement with the Mississippi Commission on Environmental Quality related to groundwater conditions arising from the closed ash pond at Plant Watson. Mississippi Power will complete an assessment and remediation consistent with the requirements of the agreement and the CCR Rule. It is anticipated that corrective action will be needed; however, an estimate of remedial costs will not be available until further site assessment is completed. Mississippi Power expects to recover the retail portion of remedial costs through the ECO Plan and the wholesale portion through MRA rates. Southern Company Gas is subject to environmental remediation liabilities associated with 40 former MGP sites in four different states. Southern Company Gas' accrued environmental remediation liability at December 31, 2020 and 2019 was based on the estimated cost of environmental investigation and remediation associated with these sites. At December 31, 2020 and 2019, the environmental remediation liability and the balance of under recovered environmental remediation costs were reflected in the balance sheets as follows: Southern Company Georgia Southern Company Gas (in millions) December 31, 2020: Environmental remediation liability: Other current liabilities $ 44 $ 15 $ 29 Accrued environmental remediation 216 — 216 Under recovered environmental remediation costs: Other regulatory assets, current $ 46 $ 12 $ 34 Other regulatory assets, deferred 265 29 236 December 31, 2019: Environmental remediation liability: Other current liabilities $ 51 $ 15 $ 36 Accrued environmental remediation 234 — 233 Under recovered environmental remediation costs: Other regulatory assets, current $ 49 $ 12 $ 37 Other regulatory assets, deferred 300 40 260 The ultimate outcome of these matters cannot be determined at this time; however, as a result of the regulatory treatment for environmental remediation expenses described above, the final disposition of these matters is not expected to have a material impact on the financial statements of the applicable Registrants. Nuclear Fuel Disposal Costs Acting through the DOE and pursuant to the Nuclear Waste Policy Act of 1982, the U.S. government entered into contracts with Alabama Power and Georgia Power that required the DOE to dispose of spent nuclear fuel generated at Plants Farley, Hatch, and Vogtle Units 1 and 2 beginning no later than January 31, 1998. The DOE has yet to commence the performance of its contractual and statutory obligation to dispose of spent nuclear fuel. Consequently, Alabama Power and Georgia Power pursued and continue to pursue legal remedies against the U.S. government for its partial breach of contract. In 2014, Alabama Power and Georgia Power filed lawsuits against the U.S. government for the costs of continuing to store spent nuclear fuel at Plants Farley, Hatch, and Vogtle Units 1 and 2 for the period from January 1, 2011 through December 31, 2013. The damage period was subsequently extended to December 31, 2014. On June 12, 2019, the Court of Federal Claims granted Alabama Power's and Georgia Power's motion for summary judgment on damages not disputed by the U.S. government, awarding those undisputed damages to Alabama Power and Georgia Power. However, those undisputed damages are not collectible and no amounts will be recognized in the financial statements until the court enters final judgment on the remaining damages. In 2017, Alabama Power and Georgia Power filed additional lawsuits against the U.S. government in the Court of Federal Claims for the costs of continuing to store spent nuclear fuel at Plants Farley, Hatch, and Vogtle Units 1 and 2 for the period from January 1, 2015 through December 31, 2017. On August 13, 2020, Alabama Power and Georgia Power filed amended complaints in each of the lawsuits adding damages from January 1, 2018 to December 31, 2019 to the claim period. The outstanding claims for the period January 1, 2011 through December 31, 2019 total $110 million and $132 million for Alabama Power and Georgia Power (based on its ownership interests), respectively. Damages will continue to accumulate until the issue is resolved, the U.S. government disposes of Alabama Power's and Georgia Power's spent nuclear fuel pursuant to its contractual obligations, or alternative storage is otherwise provided. No amounts have been recognized in the financial statements as of December 31, 2020 for any potential recoveries from the pending lawsuits. The final outcome of these matters cannot be determined at this time. However, Alabama Power and Georgia Power expect to credit any recoveries for the benefit of customers in accordance with direction from their respective PSC; therefore, no material impact on Southern Company's, Alabama Power's, or Georgia Power's net income is expected. Nuclear Insurance Under the Price-Anderson Amendments Act (Act), Alabama Power and Georgia Power maintain agreements of indemnity with the NRC that, together with private insurance, cover third-party liability arising from any nuclear incident occurring at the companies' nuclear power plants. The Act provides funds up to $13.8 billion for public liability claims that could arise from a single nuclear incident. Each nuclear plant is insured against this liability to a maximum of $450 million by American Nuclear Insurers (ANI), with the remaining coverage provided by a mandatory program of deferred premiums that could be assessed, after a nuclear incident, against all owners of commercial nuclear reactors. A company could be assessed up to $138 million per incident for each licensed reactor it operates but not more than an aggregate of $20 million per incident to be paid in a calendar year for each reactor. Such maximum assessment, excluding any applicable state premium taxes, for Alabama Power and Georgia Power, based on its ownership and buyback interests in all licensed reactors, is $275 million and $267 million, respectively, per incident, but not more than an aggregate of $41 million and $40 million, respectively, to be paid for each incident in any one year. Both the maximum assessment per reactor and the maximum yearly assessment are adjusted for inflation at least every five years. The next scheduled adjustment is due no later than November 1, 2023. See Note 5 under "Joint Ownership Agreements" for additional information on joint ownership agreements. Alabama Power and Georgia Power are members of Nuclear Electric Insurance Limited (NEIL), a mutual insurer established to provide property damage insurance in an amount up to $1.5 billion for members' operating nuclear generating facilities. Additionally, both companies have NEIL policies that currently provide decontamination, excess property insurance, and premature decommissioning coverage up to $1.25 billion for nuclear losses and policies providing coverage up to $750 million for non-nuclear losses in excess of the $1.5 billion primary coverage. NEIL also covers the additional costs that would be incurred in obtaining replacement power during a prolonged accidental outage at a member's nuclear plant. Members can purchase this coverage, subject to a deductible waiting period of up to 26 weeks, with a maximum per occurrence per unit limit of $490 million. After the deductible period, weekly indemnity payments would be received until either the unit is operational or until the limit is exhausted. Alabama Power and Georgia Power each purchase limits based on the projected full cost of replacement power, subject to ownership limitations, and have each elected a 12-week deductible waiting period for each nuclear plant. A builders' risk property insurance policy has been purchased from NEIL for the construction of Plant Vogtle Units 3 and 4. This policy provides the Vogtle Owners up to $2.75 billion for accidental property damage occurring during construction. Under each of the NEIL policies, members are subject to assessments each year if losses exceed the accumulated funds available to the insurer. The maximum annual assessments for Alabama Power and Georgia Power as of December 31, 2020 under the NEIL policies would be $56 million and $84 million, respectively. Claims resulting from terrorist acts and cyber events are covered under both the ANI and NEIL policies (subject to normal policy limits). The maximum aggregate that NEIL will pay for all claims resulting from terrorist acts and cyber events in any 12-month period is $3.2 billion each, plus such additional amounts NEIL can recover through reinsurance, indemnity, or other sources. For all on-site property damage insurance policies for commercial nuclear power plants, the NRC requires that the proceeds of such policies shall be dedicated first for the sole purpose of placing the reactor in a safe and stable condition after an accident. Any remaining proceeds are to be applied next toward the costs of decontamination and debris removal operations ordered by the NRC, and any further remaining proceeds are to be paid either to the applicable company or to its debt trustees as may be appropriate under the policies and applicable trust indentures. In the event of a loss, the amount of insurance available might not be adequate to cover property damage and other expenses incurred. Uninsured losses and other expenses, to the extent not recovered from customers, would be borne by Alabama Power or Georgia Power, as applicable, and could have a material effect on Southern Company's, Alabama Power's, and Georgia Power's financial condition and results of operations. All retrospective assessments, whether generated for liability, property, or replacement power, may be subject to applicable state premium taxes. Southern Company As discussed in Note 1 under "Leveraged Leases," a subsidiary of Southern Holdings has four leveraged lease agreements, two domestic and two international. The ability of the lessees to make required payments to the Southern Holdings subsidiary is dependent on the operational performance of the assets. Since 2017, the financial and operational performance of one of the domestic lessees and the associated generation assets raised significant concerns about the short-term ability of the generation assets to produce cash flows sufficient to support ongoing operations and the lessee's contractual obligations and its ability to make the remaining semi-annual lease payments through the end of the lease term in 2047. In addition, following the expiration of the existing power offtake agreement in 2032, the lessee also is exposed to remarketing risk, which encompasses the price and availability of alternative sources of generation. In connection with the 2019 annual impairment analysis, Southern Company revised the estimated cash flows to be received under the leveraged lease, which resulted in an impairment charge of $17 million ($13 million after tax) recorded in the fourth quarter 2019. During the second quarter 2020, Southern Company received the latest annual forecasts of natural gas prices and considered the significant decline in forecasted prices to be an indicator of potential impairment that required an interim impairment assessment. Accordingly, consistent with prior impairment analyses, Southern Company evaluated the recoverability of the lease receivable and the expected residual value of the generation assets under various natural gas price scenarios to estimate the cash flows expected to be received from remarketing the generation assets following the expiration of the existing PPA and the residual value of the generation assets at the end of the lease. Based on the current forecasts of energy prices in the years following the expiration of the existing PPA, Southern Company concluded that it is no longer probable that any of the associated rental payments will be received, because it is no longer probable the generation assets will be successfully remarketed and continue to operate after that date. During the second quarter 2020, Southern Company revised the estimated cash flows to be received under the leveraged lease to reflect this conclusion, which resulted in a full impairment of the lease investment and a pre-tax charge to earnings of $154 million ($74 million after tax). All required lease payments through December 31, 2020 have been paid in full. If any future lease payments due prior to the expiration of the associated PPA are not paid in full, the Southern Holdings subsidiary may be unable to make its corresponding payment to the holders of the underlying non-recourse debt related to the generation assets. Failure to make the required payment to the debtholders could represent an event of default that would give the debtholders the right to foreclose on, and take ownership of, the generation assets, in effect terminating the lease. As the remaining amount of the lease investment was charged against earnings in the second quarter 2020, termination would not be expected to result in additional charges. Southern Company will continue to monitor the operational performance of the underlying assets and evaluate the ability of the lessee to continue to make the required lease payments and meet its obligations associated with a future closure or retirement of the generation assets and associated properties, including the dry ash landfill. During the fourth quarter 2020, Southern Company management initiated steps to sell the investment in its other domestic leveraged lease and reclassified the investment as held for sale. In connection with the annual impairment analysis of this investment, Southern Company management concluded that the estimated residual value of the generation assets should be reduced due to significant uncertainty as to whether the related natural gas generation assets will continue to operate at the end of the lease term in 2040 and recorded the resulting impairment charge. An additional charge was recorded to further reduce the related investment in the leveraged lease to its estimated fair value, less costs to sell. The pre-tax charges to earnings in the fourth quarter 2020 totaled $52 million ($31 million after tax). See Note 15 under "Assets Held for Sale" for additional information. The leveraged lease agreements for the two international projects include lessee purchase options related to the leased assets, which consist of nine gas distribution networks and two district heating systems in the Netherlands. The lessee has communicated its intent to exercise the first purchase option in 2022. The purchase options for the remaining ten assets are exercisable on various dates through 2028 with at least one year's notice. The exercise of these purchase options is not expected to result in any gain or loss. Mississippi Power Kemper County Energy Facility The Kemper County energy facility was designed to utilize IGCC technology with an expected output capacity of 582 MWs and to be fueled by locally mined lignite from a mine owned by Mississippi Power and situated adjacent to the Kemper County energy facility. In 2012, the Mississippi PSC issued an order confirming the CPCN originally approved by the Mississippi PSC in 2010 authorizing the acquisition, construction, and operation of the Kemper County energy facility. Mississippi Power placed the combined cycle and the associated common facilities portion of the Kemper County energy facility in service in 2014 and dedicated them as Plant Ratcliffe in 2018. In 2017, the Mississippi PSC issued an order directing Mississippi Power to pursue a settlement under which the Kemper County energy facility would be operated as a natural gas plant, rather than an IGCC plant, and address all issues associated with the Kemper County energy facility. Following this order, cost recovery of the gasifier portions was no longer probable and Mississippi Power recorded significant charges to income in 2017. In 2018, the Mississippi PSC approved a settlement agreement for the Kemper County energy facility, which resolved all cost recovery issues, modified the CPCN to limit the Kemper County energy facility to natural gas combined cycle operation, and reduced retail customer rates by approximately $26.8 million annually based on a revenue requirement that included no recovery for costs associated with the gasifier portion of the Kemper County energy facility. In 2018, 2019, and 2020, Mississippi Power recorded charges to income associated with abandonment and related closure costs and ongoing period costs, net of salvage proceeds, for the mine and gasifier-related assets at the Kemper County energy facility. These charges, including related tax impacts, totaled $37 million pre-tax ($68 million benefit after tax) in 2018, $24 million pre-tax and after tax in 2019, and $4 million pre-tax ($3 million after tax) in 2020. The pre-tax charges are included in other operations and maintenance expenses on the statements of income. Dismantlement of the abandoned gasifier-related assets and site restoration activities are expected to be completed by 2026. Additional pre-tax period costs associated with dismantlement and site restoration activities, including related costs for compliance and safety, ARO accretion, and property taxes, net of salvage, are estimated to total $10 million to $20 million annually through 2025. The Mississippi Power Rate Case Settlement Agreement eliminated separate rates associated with the Kemper County energy facility and included these costs in rates for PEP, ECO Plan, and ad valorem taxes, as applicable, effective with the revised rates in 2020. See Note 2 under "Mississippi Power – 2019 Base Rate Case" for additional information. Lignite Mine and CO 2 Pipeline Facilities Mississippi Power owns the lignite mine and equipment and mineral reserves located around the Kemper County energy facility site. The mine started commercial operation in 2013. In connection with the Kemper County energy facility construction, Mississippi Power also constructed a pipeline for the transport of captured CO 2 . In 2010, Mississippi Power executed a management fee contract with Liberty Fuels Company, LLC (Liberty Fuels), a wholly-owned subsidiary of The North American Coal Corporation, which developed, constructed, and is responsible for the mining operations through the end of the mine reclamation. As the mining permit holder, Liberty Fuels has a legal obligation to perform mine reclamation and Mississippi Power has a contractual obligation to fund all reclamation activities. As a result of the abandonment of the Kemper IGCC, final mine reclamation began in 2018 and was substantially completed in 2020, with monitoring expected to continue through 2027. See Note 6 for additional information. In December 2019, Mississippi Power transferred ownership of the CO 2 pipeline to an unrelated gas pipeline company, with no resulting impact on income. In conjunction with the transfer of the CO 2 pipeline, the parties agreed to enter into a 15-year firm transportation agreement, which became effective in December 2020, upon the conversion by the pipeline company of the CO 2 pipeline to a natural gas pipeline to be used for the delivery of natural gas to Plant Ratcliffe. The agreement is treated as a finance lease for accounting purposes. See Note 9 for additional information. Government Grants In 2010, the DOE, through a cooperative agreement with SCS, agreed to fund $270 million of the Kemper County energy facility through the grants awarded to the project by the DOE under the Clean Coal Power Initiative Round 2. In 2016, additional DOE grants in the amount of $137 million were awarded to the Kemper County energy facility. In 2018, Mississippi Power filed with the DOE its request for property closeout certification under the contract related to the $387 million of total grants received. On September 3, 2020, Mississippi Power and Southern Company executed an agreement with the DOE completing Mississippi Power's request, which enabled Mississippi Power to proceed with full dismantlement of the abandoned gasifier-related assets and site restoration activities. The expected impact of the closeout agreement was accrued in 2019. In connection with the DOE closeout discussions, in A |
REVENUE FROM CONTRACTS WITH CUS
REVENUE FROM CONTRACTS WITH CUSTOMERS | 12 Months Ended |
Dec. 31, 2020 | |
Revenue from Contract with Customer [Abstract] | |
REVENUE FROM CONTRACTS WITH CUSTOMERS | REVENUE FROM CONTRACTS WITH CUSTOMERS The Registrants generate revenues from a variety of sources, some of which are not accounted for as revenue from contracts with customers, such as leases, derivatives, and certain cost recovery mechanisms. See Note 1 under "Revenues" for additional information on the revenue policies of the Registrants. See Notes 9 and 14 for additional information on revenue accounted for under lease and derivative accounting guidance, respectively. The following table disaggregates revenue from contracts with customers for the periods presented: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) 2020 Operating revenues Retail electric revenues Residential $ 6,113 $ 2,377 $ 3,476 $ 260 $ — $ — Commercial 4,699 1,512 2,933 254 — — Industrial 2,775 1,293 1,197 285 — — Other 90 21 60 9 — — Total retail electric revenues 13,677 5,203 7,666 808 — — Natural gas distribution revenues Residential 1,338 — — — — 1,338 Commercial 340 — — — — 340 Transportation 971 — — — — 971 Industrial 30 — — — — 30 Other 209 — — — — 209 Total natural gas distribution revenues 2,888 — — — — 2,888 Wholesale electric revenues PPA energy revenues 735 133 42 9 570 — PPA capacity revenues 454 108 50 3 296 — Non-PPA revenues 210 43 10 311 239 — Total wholesale electric revenues 1,399 284 102 323 1,105 — Other natural gas revenues Wholesale gas services 1,727 — — — — 1,727 Gas marketing services 391 — — — — 391 Other natural gas revenues 33 — — — — 33 Total natural gas revenues 2,151 — — — — 2,151 Other revenues 982 159 447 26 14 — Total revenue from contracts with customers 21,097 5,646 8,215 1,157 1,119 5,039 Other revenue sources (a) 3,764 184 94 15 614 2,881 Other adjustments (b) (4,486) — — — — (4,486) Total operating revenues $ 20,375 $ 5,830 $ 8,309 $ 1,172 $ 1,733 $ 3,434 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) 2019 Operating revenues Retail electric revenues Residential $ 6,164 $ 2,509 $ 3,377 $ 278 $ — $ — Commercial 5,065 1,677 3,097 291 — — Industrial 3,126 1,460 1,360 306 — — Other 90 25 54 11 — — Total retail electric revenues 14,445 5,671 7,888 886 — — Natural gas distribution revenues Residential 1,413 — — — — 1,413 Commercial 389 — — — — 389 Transportation 907 — — — — 907 Industrial 35 — — — — 35 Other 245 — — — — 245 Total natural gas distribution revenues 2,989 — — — — 2,989 Wholesale electric revenues PPA energy revenues 833 145 60 11 648 — PPA capacity revenues 453 102 54 3 322 — Non-PPA revenues 232 81 9 352 238 — Total wholesale electric revenues 1,518 328 123 366 1,208 — Other natural gas revenues Gas pipeline investments 32 — — — — 32 Wholesale gas services 2,095 — — — — 2,095 Gas marketing services 440 — — — — 440 Other natural gas revenues 42 — — — — 42 Total other natural gas revenues 2,609 — — — — 2,609 Other revenues 1,035 153 407 19 12 — Total revenue from contracts with customers 22,596 6,152 8,418 1,271 1,220 5,598 Other revenue sources (a) 4,266 (27) (10) (7) 718 3,637 Other adjustments (b) (5,443) — — — — (5,443) Total operating revenues $ 21,419 $ 6,125 $ 8,408 $ 1,264 $ 1,938 $ 3,792 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) 2018 Operating revenues Retail electric revenues Residential $ 6,586 $ 2,285 $ 3,295 $ 277 $ — $ — Commercial 5,255 1,541 3,025 290 — — Industrial 3,152 1,364 1,321 326 — — Other 94 25 56 9 — — Total retail electric revenues 15,087 5,215 7,697 902 — — Natural gas distribution revenues Residential 1,525 — — — — 1,525 Commercial 436 — — — — 436 Transportation 944 — — — — 944 Industrial 40 — — — — 40 Other 230 — — — — 230 Total natural gas distribution revenues 3,175 — — — — 3,175 Wholesale electric revenues PPA energy revenues 950 158 81 15 727 — PPA capacity revenues 498 101 53 6 394 — Non-PPA revenues 263 119 24 329 230 — Total wholesale electric revenues 1,711 378 158 350 1,351 — Other natural gas revenues Gas pipeline investments 32 — — — — 32 Wholesale gas services 3,083 — — — — 3,083 Gas marketing services 571 — — — — 571 Other natural gas revenues 53 — — — — 53 Total other natural gas revenues 3,739 — — — — 3,739 Other revenues 1,529 210 236 22 13 — Total revenue from contracts with customers 25,241 5,803 8,091 1,274 1,364 6,914 Other revenue sources (a) 5,108 229 329 (9) 841 3,849 Other adjustments (b) (6,854) — — — — (6,854) Total operating revenues $ 23,495 $ 6,032 $ 8,420 $ 1,265 $ 2,205 $ 3,909 (a) Other revenue sources relate to revenues from customers accounted for as derivatives and leases, alternative revenue programs at Southern Company Gas, and cost recovery mechanisms and revenues that meet other scope exceptions for revenues from contracts with customers at the traditional electric operating companies. (b) Other adjustments relate to the cost of Southern Company Gas' energy and risk management activities. Wholesale gas services revenues are presented net of the related costs of those activities on the statement of income. See Note 16 under "Southern Company Gas" for additional information on the components of wholesale gas services' operating revenues. Contract Balances The following table reflects the closing balances of receivables, contract assets, and contract liabilities related to revenues from contracts with customers at December 31, 2020 and 2019: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Accounts Receivables As of December 31, 2020 $ 2,614 $ 632 $ 806 $ 77 $ 112 $ 788 As of December 31, 2019 2,413 586 688 79 97 749 Contract Assets As of December 31, 2020 $ 158 $ 2 $ 71 $ — $ — $ — As of December 31, 2019 117 — 69 — — — Contract Liabilities As of December 31, 2020 $ 61 $ 6 $ 27 $ 1 $ 1 $ 1 As of December 31, 2019 52 10 13 — 1 1 As of December 31, 2020 and 2019, Georgia Power had contract assets primarily related to unregulated service agreements, where payment is contingent on project completion, and fixed retail customer bill programs, where the payment is contingent upon Georgia Power's continued performance and the customer's continued participation in the program over a one-year contract term. Contract liabilities for Georgia Power relate to cash collections recognized in advance of revenue for certain unregulated service agreements. Alabama Power had contract liabilities for outstanding performance obligations primarily related to pole attachment and extended service agreements. Southern Company's unregulated distributed generation business had contract assets of $81 million and $40 million at December 31, 2020 and 2019, respectively, and contract liabilities of $27 million and $28 million at December 31, 2020 and 2019, respectively, for outstanding performance obligations. The following table reflects revenue from contracts with customers recognized in 2020 and 2019 included in the contract liability at December 31, 2019 and December 31, 2018, respectively, for the applicable Registrants: Southern Company Alabama Power Georgia Power Southern Power Southern Company Gas (in millions) Revenue Recognized 2020 $ 33 $ 10 $ 8 $ 1 $ 1 2019 30 11 6 11 2 Remaining Performance Obligations The traditional electric operating companies and Southern Power have long-term contracts with customers in which revenues are recognized as performance obligations are satisfied over the contract term. These contracts primarily relate to PPAs whereby the traditional electric operating companies and Southern Power provide electricity and generation capacity to a customer. The revenue recognized for the delivery of electricity is variable; however, certain PPAs include a fixed payment for fixed generation capacity over the term of the contract. Southern Company's unregulated distributed generation business also has partially satisfied performance obligations related to certain fixed price contracts. Revenues from contracts with customers related to these performance obligations remaining at December 31, 2020 are expected to be recognized as follows: 2021 2022 2023 2024 2025 Thereafter (in millions) Southern Company $ 547 $ 395 $ 338 $ 326 $ 306 $ 2,634 Alabama Power 33 31 24 7 5 — Georgia Power 75 46 35 24 21 42 Southern Power 285 287 280 296 280 2,610 Revenue expected to be recognized for performance obligations remaining at December 31, 2020 was immaterial for Mississippi Power. |
PROPERTY, PLANT, AND EQUIPMENT
PROPERTY, PLANT, AND EQUIPMENT (Notes) | 12 Months Ended |
Dec. 31, 2020 | |
Property, Plant and Equipment [Abstract] | |
PROPERTY, PLANT, AND EQUIPMENT | PROPERTY, PLANT, AND EQUIPMENT Property, plant, and equipment is stated at original cost or fair value at acquisition, as appropriate, less any regulatory disallowances and impairments. Original cost may include: materials; labor; minor items of property; appropriate administrative and general costs; payroll-related costs such as taxes, pensions, and other benefits; and the interest capitalized and/or cost of equity funds used during construction. The Registrants' property, plant, and equipment in service consisted of the following at December 31, 2020 and 2019: At December 31, 2020: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Electric utilities: Generation $ 52,179 $ 16,201 $ 18,675 $ 2,819 $ 13,872 $ — Transmission 12,879 5,033 6,951 856 — — Distribution 20,958 8,248 11,622 1,088 — — General/other 5,072 2,334 2,434 248 32 — Electric utilities' plant in service 91,088 31,816 39,682 5,011 13,904 — Southern Company Gas: Natural gas distribution utilities transportation and distribution 14,610 — — — — 14,610 Storage facilities 1,752 — — — — 1,752 Other 1,249 — — — — 1,249 Southern Company Gas plant in service 17,611 — — — — 17,611 Other plant in service 1,817 — — — — — Total plant in service $ 110,516 $ 31,816 $ 39,682 $ 5,011 $ 13,904 $ 17,611 At December 31, 2019: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Electric utilities: Generation $ 50,329 $ 15,329 $ 18,341 $ 2,786 $ 13,241 $ — Transmission 12,157 4,719 6,590 808 — — Distribution 19,846 7,798 11,024 1,024 — — General/other 4,650 2,177 2,182 239 29 — Electric utilities' plant in service 86,982 30,023 38,137 4,857 13,270 — Southern Company Gas: Natural gas distribution utilities transportation and distribution 13,518 — — — — 13,518 Storage facilities 1,634 — — — — 1,634 Other 1,192 — — — — 1,192 Southern Company Gas plant in service 16,344 — — — — 16,344 Other plant in service 1,788 — — — — — Total plant in service $ 105,114 $ 30,023 $ 38,137 $ 4,857 $ 13,270 $ 16,344 The cost of replacements of property, exclusive of minor items of property, is capitalized. The cost of maintenance, repairs, and replacement of minor items of property is charged to other operations and maintenance expenses as incurred or performed with the exception of nuclear refueling costs and certain maintenance costs including those described below. In accordance with orders from their respective state PSCs, Alabama Power and Georgia Power defer nuclear refueling outage operations and maintenance expenses to a regulatory asset when the charges are incurred. Alabama Power amortizes the costs over a subsequent 18-month period with Plant Farley's fall outage cost amortization beginning in January of the following year and spring outage cost amortization beginning in July of the same year. Georgia Power amortizes its costs over each unit's operating cycle, or 18 months for Plant Vogtle Units 1 and 2 and 24 months for Plant Hatch Units 1 and 2. Georgia Power's amortization period begins the month the refueling outage starts. A portion of Mississippi Power's railway track maintenance costs is charged to fuel stock and recovered through Mississippi Power's fuel clause. The portion of Southern Company Gas' non-working gas used to maintain the structural integrity of natural gas storage facilities that is considered to be non-recoverable is depreciated, while the recoverable or retained portion is not depreciated. See Note 9 for information on finance lease right-of-use (ROU) assets, net, which are included in property, plant, and equipment. The Registrants have deferred certain implementation costs related to cloud hosting arrangements. Once a hosted software is placed into service, the related deferred costs are amortized on a straight-line basis over the remaining expected hosting arrangement term, including any renewal options that are reasonably certain of exercise. The amortization is reflected with the associated cloud hosting fees, which are generally reflected in other operations and maintenance expenses on the Registrants' statements of income. At December 31, 2020, deferred cloud implementation costs, which are generally included in other deferred charges and assets on the Registrants' balance sheets, are as follows: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) At December 31, 2020: Deferred cloud implementation costs $ 162 $ 38 $ 58 $ 7 $ 9 $ 17 Depreciation and Amortization The traditional electric operating companies' and Southern Company Gas' depreciation of the original cost of utility plant in service is provided primarily by using composite straight-line rates. The approximate rates for 2020, 2019, and 2018 are as follows: 2020 2019 2018 Alabama Power 2.6 % 3.1 % 3.0 % Georgia Power 3.0 % 2.6 % 2.6 % Mississippi Power 3.7 % 3.7 % 4.2 % Southern Company Gas 2.8 % 2.9 % 2.9 % Depreciation studies are conducted periodically to update the composite rates. These studies are filed with the respective state PSC and/or other applicable state and federal regulatory agencies for the traditional electric operating companies and the natural gas distribution utilities. During 2020, Georgia Power, Mississippi Power, and Atlanta Gas Light revised their depreciation rates in accordance with base rate case approvals by their respective PSCs. The revised rates were effective January 1, 2020 for Georgia Power and Atlanta Gas Light and April 1, 2020 for Mississippi Power. See Note 2 for additional information. When property, plant, and equipment subject to composite depreciation is retired or otherwise disposed of in the normal course of business, its original cost, together with the cost of removal, less salvage, is charged to accumulated depreciation. For other property dispositions, the applicable cost and accumulated depreciation are removed from the balance sheet accounts, and a gain or loss is recognized. Minor items of property included in the original cost of the asset are retired when the related property unit is retired. At December 31, 2020 and 2019, accumulated depreciation for Southern Company and Southern Company Gas consisted of utility plant in service totaling $31.6 billion and $30.0 billion, respectively, for Southern Company and $4.6 billion and $4.5 billion, respectively, for Southern Company Gas, as well as other plant in service totaling $817 million and $732 million, respectively, for Southern Company and $195 million and $155 million, respectively, for Southern Company Gas. Other plant in service includes the non-utility assets of Southern Company Gas, as well as, for Southern Company, certain other non-utility subsidiaries. Depreciation of the original cost of other plant in service is provided primarily on a straight-line basis over estimated useful lives. Useful lives for Southern Company Gas's non-utility assets range from five Southern Power Southern Power applies component depreciation, where depreciation is computed principally by the straight-line method over the estimated useful life of the asset. Certain of Southern Power's generation assets related to natural gas-fired facilities are depreciated on a units-of-production basis, using hours or starts, to better match outage and maintenance costs to the usage of, and revenues from, these assets. The primary assets in Southern Power's property, plant, and equipment are generating facilities, which generally have estimated useful lives as follows: Southern Power Generating Facility Useful life Natural gas Up to 50 years (*) Solar Up to 35 years Wind Up to 30 years (*) Effective January 1, 2020, Southern Power revised the depreciable lives of its natural gas generating facilities from up to 45 years to up to 50 years. This revision resulted in an immaterial decrease in depreciation for 2020. When Southern Power's depreciable property, plant, and equipment is retired, or otherwise disposed of in the normal course of business, the applicable cost and accumulated depreciation is removed and a gain or loss is recognized in the statements of income. Southern Power reviews its estimated useful lives and salvage values on an ongoing basis. The results of these reviews could result in changes which could have a material impact on Southern Power's net income. Joint Ownership Agreements At December 31, 2020, the Registrants' percentage ownership and investment (exclusive of nuclear fuel) in jointly-owned facilities in commercial operation were as follows: Facility (Type) Percent Plant in Service Accumulated CWIP (in millions) Alabama Power Greene County (natural gas) Units 1 and 2 60.0 % (a) $ 189 $ 76 $ 2 Plant Miller (coal) Units 1 and 2 91.8 (b) 2,107 650 24 Georgia Power Plant Hatch (nuclear) 50.1 % (c) $ 1,352 $ 624 $ 37 Plant Vogtle (nuclear) Units 1 and 2 45.7 (c) 3,592 2,221 55 Plant Scherer (coal) Units 1 and 2 8.4 (c) 279 98 1 Plant Scherer (coal) Unit 3 75.0 (c) 1,320 520 4 Plant Wansley (coal) 53.5 (c) 1,068 418 10 Rocky Mountain (pumped storage) 25.4 (d) 183 144 1 Mississippi Power Greene County (natural gas) Units 1 and 2 40.0 % (a) $ 122 $ 54 $ 1 Plant Daniel (coal) Units 1 and 2 50.0 (e) 775 238 15 Southern Company Gas Dalton Pipeline (natural gas pipeline) 50.0 % (f) $ 271 $ 15 $ — (a) Jointly owned by Alabama Power and Mississippi Power and operated and maintained by Alabama Power. (b) Jointly owned with PowerSouth and operated and maintained by Alabama Power. (c) Georgia Power owns undivided interests in Plants Hatch, Vogtle Units 1 and 2, Scherer, and Wansley in varying amounts jointly with one or more of the following entities: OPC, MEAG Power, Dalton, Florida Power & Light Company, JEA, and Gulf Power. Georgia Power has been contracted to operate and maintain the plants as agent for the co-owners and is jointly and severally liable for third party claims related to these plants. (d) Jointly owned with OPC, which is the operator of the plant. (e) Jointly owned by Gulf Power and Mississippi Power. In accordance with the operating agreement, Mississippi Power acts as Gulf Power's agent with respect to the operation and maintenance of these units. See Note 3 under "Other Matters – Mississippi Power – Plant Daniel" for information regarding a commitment between Mississippi Power and Gulf Power to seek a restructuring of their 50% undivided ownership interests in Plant Daniel. (f) Jointly owned with The Williams Companies, Inc., the Dalton Pipeline is a 115-mile natural gas pipeline that serves as an extension of the Transcontinental Gas Pipe Line Company, LLC pipeline system into northwest Georgia. Southern Company Gas leases its 50% undivided ownership for approximately $26 million annually through 2042. The lessee is responsible for maintaining the pipeline during the lease term and for providing service to transportation customers under its FERC-regulated tariff. Georgia Power also owns 45.7% of Plant Vogtle Units 3 and 4, which are currently under construction and had a CWIP balance of $7.3 billion at December 31, 2020, excluding estimated probable losses recorded in 2018 and 2020. See Note 2 under "Georgia Power – Nuclear Construction" for additional information. The Registrants' proportionate share of their jointly-owned facility operating expenses is included in the corresponding operating expenses in the statements of income and each Registrant is responsible for providing its own financing. Assets Subject to Lien In 2018, the Mississippi PSC approved executed agreements between Mississippi Power and its largest retail customer, Chevron Products Company (Chevron), for Mississippi Power to continue providing retail service to the Chevron refinery in Pascagoula, Mississippi through 2038. The agreements grant Chevron a security interest in the co-generation assets owned by Mississippi Power, with a lease receivable balance of $138 million at December 31, 2020, located at the refinery that is exercisable upon the occurrence of (i) certain bankruptcy events or (ii) other events of default coupled with specific reductions in steam output at the facility and a downgrade of Mississippi Power's credit rating to below investment grade by two of the three rating agencies. |
ASSET RETIREMENT OBLIGATIONS
ASSET RETIREMENT OBLIGATIONS | 12 Months Ended |
Dec. 31, 2020 | |
Asset Retirement Obligation Disclosure [Abstract] | |
ASSET RETIREMENT OBLIGATIONS | ASSET RETIREMENT OBLIGATIONS AROs are computed as the present value of the estimated costs for an asset's future retirement and are recorded in the period in which the liability is incurred. The estimated costs are capitalized as part of the related long-lived asset and depreciated over the asset's useful life. In the absence of quoted market prices, AROs are estimated using present value techniques in which estimates of future cash outlays associated with the asset retirements are discounted using a credit-adjusted risk-free rate. Estimates of the timing and amounts of future cash outlays are based on projections of when and how the assets will be retired and the cost of future removal activities. Each traditional electric operating company and natural gas distribution utility has received accounting guidance from its state PSC or applicable state regulatory agency allowing the continued accrual or recovery of other retirement costs for long-lived assets that it does not have a legal obligation to retire. Accordingly, the accumulated removal costs for these obligations are reflected in the balance sheets as regulatory liabilities and amounts to be recovered are reflected in the balance sheets as regulatory assets. The ARO liabilities for the traditional electric operating companies primarily relate to facilities that are subject to the CCR Rule and the related state rules, principally ash ponds. In addition, Alabama Power and Georgia Power have retirement obligations related to the decommissioning of nuclear facilities (Alabama Power's Plant Farley and Georgia Power's ownership interests in Plant Hatch and Plant Vogtle Units 1 and 2). See "Nuclear Decommissioning" herein for additional information. Other significant AROs include various landfill sites and asbestos removal for Alabama Power, Georgia Power, and Mississippi Power and gypsum cells and mine reclamation for Mississippi Power. The ARO liability for Southern Power primarily relates to its solar and wind facilities, which are located on long-term land leases requiring the restoration of land at the end of the lease. The traditional electric operating companies and Southern Company Gas also have identified other retirement obligations, such as obligations related to certain electric transmission and distribution facilities, certain asbestos-containing material within long-term assets not subject to ongoing repair and maintenance activities, certain wireless communication towers, the disposal of polychlorinated biphenyls in certain transformers, leasehold improvements, equipment on customer property, and property associated with the Southern Company system's rail lines and natural gas pipelines. However, liabilities for the removal of these assets have not been recorded because the settlement timing for certain retirement obligations related to these assets is indeterminable and, therefore, the fair value of the retirement obligations cannot be reasonably estimated. A liability for these retirement obligations will be recognized when sufficient information becomes available to support a reasonable estimation of the ARO. Southern Company and the traditional electric operating companies will continue to recognize in their respective statements of income allowed removal costs in accordance with regulatory treatment. Any differences between costs recognized in accordance with accounting standards related to asset retirement and environmental obligations and those reflected in rates are recognized as either a regulatory asset or liability in the balance sheets as ordered by the various state PSCs. Details of the AROs included in the balance sheets are as follows: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power (*) (in millions) Balance at December 31, 2018 $ 9,394 $ 3,210 $ 5,829 $ 160 $ 84 Liabilities incurred 37 — 35 1 1 Liabilities settled (328) (127) (151) (35) — Accretion 402 145 243 7 4 Cash flow revisions 281 312 (172) 57 — Balance at December 31, 2019 $ 9,786 $ 3,540 $ 5,784 $ 190 $ 89 Liabilities incurred 19 — 10 — 9 Liabilities settled (442) (219) (185) (22) — Accretion 409 152 238 8 4 Cash flow revisions 912 501 418 — (7) Balance at December 31, 2020 $ 10,684 $ 3,974 $ 6,265 $ 176 $ 95 (*) Included in other deferred credits and liabilities on Southern Power's consolidated balance sheets. During 2019, Alabama Power recorded increases totaling approximately $312 million to its AROs primarily related to the CCR Rule and the related state rule based on management's completion of closure designs during the second and third quarters 2019 under the planned closure-in-place methodology for all but one of its ash pond facilities. During 2019, Mississippi Power recorded an increase of approximately $57 million to its AROs related to the CCR Rule, primarily associated with the ash pond facility at Plant Greene County, which is jointly owned with Alabama Power. During 2020, Alabama Power recorded increases totaling approximately $501 million to its AROs related to the CCR Rule and the related state rule primarily as a result of management's completion of the closure design for the remaining ash pond and the addition of a water treatment system to the design of another ash pond. The additional estimated costs to close these ash ponds under the planned closure-in-place methodology primarily relate to inputs from contractor bids, design revisions, and changes in the expected volume of ash handling. During the second half of 2019, Georgia Power completed an assessment of its plans to close the ash ponds at all of its generating plants in compliance with the CCR Rule and the related state rule. Cost estimates were revised to reflect further refined costs for closure plans and updates to the timing of future cash outlays. As a result, in December 2019, Georgia Power recorded a decrease of approximately $174 million to its AROs related to the CCR Rule and the related state rule. During the third quarter 2020, Georgia Power further refined the related cost estimates, including updates to long-term post-closure care requirements, market pricing, and timing of future cash outlays. As a result, in September 2020, Georgia Power recorded an increase of approximately $411 million to its AROs related to the CCR Rule and the related state rule. The cost estimates for AROs related to the disposal of CCR are based on information at December 31, 2020 using various assumptions related to closure and post-closure costs, timing of future cash outlays, inflation and discount rates, and the potential methods for complying with the CCR Rule and the related state rules. The traditional electric operating companies have periodically updated, and expect to continue periodically updating, their related cost estimates and ARO liabilities for each CCR unit as additional information related to these assumptions becomes available. Some of these updates have been, and future updates may be, material. Additionally, the closure designs and plans in the States of Alabama and Georgia are subject to approval by environmental regulatory agencies. Absent continued recovery of ARO costs through regulated rates, results of operations, cash flows, and financial condition for Southern Company and the traditional electric operating companies could be materially impacted. See Note 2 under "Georgia Power – Rate Plans" for additional information. The ultimate outcome of these matters cannot be determined at this time. Nuclear Decommissioning The NRC requires licensees of commercial nuclear power reactors to establish a plan for providing reasonable assurance of funds for future decommissioning. Alabama Power and Georgia Power have external trust funds (Funds) to comply with the NRC's regulations. Use of the Funds is restricted to nuclear decommissioning activities. The Funds are managed and invested in accordance with applicable requirements of various regulatory bodies, including the NRC, the FERC, and state PSCs, as well as the IRS. While Alabama Power and Georgia Power are allowed to prescribe an overall investment policy to the Funds' managers, neither Southern Company nor its subsidiaries or affiliates are allowed to engage in the day-to-day management of the Funds or to mandate individual investment decisions. Day-to-day management of the investments in the Funds is delegated to unrelated third-party managers with oversight by the management of Alabama Power and Georgia Power. The Funds' managers are authorized, within certain investment guidelines, to actively buy and sell securities at their own discretion in order to maximize the return on the Funds' investments. The Funds are invested in a tax-efficient manner in a diversified mix of equity and fixed income securities and are reported as trading securities. Alabama Power and Georgia Power record the investment securities held in the Funds at fair value, as disclosed in Note 13, as management believes that fair value best represents the nature of the Funds. Gains and losses, whether realized or unrealized, are recorded in the regulatory liability for AROs in the balance sheets and are not included in net income or OCI. Fair value adjustments and realized gains and losses are determined on a specific identification basis. The Funds at Georgia Power participate in a securities lending program through the managers of the Funds. Under this program, Georgia Power's Funds' investment securities are loaned to institutional investors for a fee. Securities loaned are fully collateralized by cash, letters of credit, and/or securities issued or guaranteed by the U.S. government or its agencies or instrumentalities. At December 31, 2020 and 2019, approximately $44 million and $28 million, respectively, of the fair market value of Georgia Power's Funds' securities were on loan and pledged to creditors under the Funds' managers' securities lending program. The fair value of the collateral received was approximately $45 million and $29 million at December 31, 2020 and 2019, respectively, and can only be sold by the borrower upon the return of the loaned securities. The collateral received is treated as a non-cash item in the statements of cash flows. Investment securities in the Funds for December 31, 2020 and 2019 were as follows: Southern Company Alabama Georgia (in millions) At December 31, 2020: Equity securities $ 1,339 $ 842 $ 497 Debt securities 851 231 620 Other securities 111 83 28 Total investment securities in the Funds $ 2,301 $ 1,156 $ 1,145 At December 31, 2019: Equity securities $ 1,159 $ 743 $ 416 Debt securities 798 218 580 Other securities 77 60 17 Total investment securities in the Funds $ 2,034 $ 1,021 $ 1,013 These amounts exclude receivables related to investment income and pending investment sales and payables related to pending investment purchases. For Southern Company and Georgia Power, these amounts include Georgia Power's investment securities pledged to creditors and collateral received and excludes payables related to Georgia Power's securities lending program. The fair value increases (decreases) of the Funds, including unrealized gains (losses) and reinvested interest and dividends and excluding the Funds' expenses, for 2020, 2019, and 2018 are shown in the table below. Southern Company Alabama Georgia (in millions) Fair value increases (decreases) 2020 $ 280 $ 142 $ 138 2019 344 194 150 2018 (67) (38) (29) Unrealized gains (losses) At December 31, 2020 $ 220 $ 121 $ 99 At December 31, 2019 259 149 110 At December 31, 2018 (183) (96) (87) The investment securities held in the Funds continue to be managed with a long-term focus. Accordingly, all purchases and sales within the Funds are presented separately in the statements of cash flows as investing cash flows, consistent with the nature of the securities and purpose for which the securities were acquired. For Alabama Power, approximately $15 million and $16 million at December 31, 2020 and 2019, respectively, previously recorded in internal reserves is being transferred into the Funds through 2040 as approved by the Alabama PSC. The NRC's minimum external funding requirements are based on a generic estimate of the cost to decommission only the radioactive portions of a nuclear unit based on the size and type of reactor. Alabama Power and Georgia Power have filed plans with the NRC designed to ensure that, over time, the deposits and earnings of the Funds will provide the minimum funding amounts prescribed by the NRC. At December 31, 2020 and 2019, the accumulated provisions for the external decommissioning trust funds were as follows: 2020 2019 (in millions) Alabama Power Plant Farley $ 1,156 $ 1,021 Georgia Power Plant Hatch $ 716 $ 634 Plant Vogtle Units 1 and 2 429 379 Total $ 1,145 $ 1,013 Site study cost is the estimate to decommission a specific facility as of the site study year. The decommissioning cost estimates are based on prompt dismantlement and removal of the plant from service. The actual decommissioning costs may vary from these estimates because of changes in the assumed date of decommissioning, changes in NRC requirements, or changes in the assumptions used in making these estimates. The estimated costs of decommissioning at December 31, 2020 based on the most current studies, which were each performed in 2018, were as follows: Plant Plant Hatch (*) Plant Vogtle Units 1 and 2 (*) Decommissioning periods: Beginning year 2037 2034 2047 Completion year 2076 2075 2079 (in millions) Site study costs: Radiated structures $ 1,234 $ 734 $ 601 Spent fuel management 387 172 162 Non-radiated structures 99 56 79 Total site study costs $ 1,720 $ 962 $ 842 (*) Based on Georgia Power's ownership interests. For ratemaking purposes, Alabama Power's decommissioning costs are based on the site study and Georgia Power's decommissioning costs are based on the NRC generic estimate to decommission the radioactive portion of the facilities and the site study estimate for spent fuel management as of 2018. Significant assumptions used to determine these costs for ratemaking were an estimated inflation rate of 4.5% and 2.75% for Alabama Power and Georgia Power, respectively, and an estimated trust earnings rate of 7.0% and 4.75% for Alabama Power and Georgia Power, respectively. Amounts previously contributed to the Funds for Plant Farley are currently projected to be adequate to meet the decommissioning obligations. Alabama Power will continue to provide site-specific estimates of the decommissioning costs and related projections of funds in the external trust to the Alabama PSC and, if necessary, would seek the Alabama PSC's approval to address any changes in a manner consistent with NRC and other applicable requirements. Effective January 1, 2020, in connection with the 2019 ARP, Georgia Power's annual decommissioning cost for ratemaking is a total of $4 million for Plant Hatch and Plant Vogtle Units 1 and 2. Georgia Power's annual decommissioning cost for ratemaking in 2019 totaled $5 million. |
CONSOLIDATED ENTITIES AND EQUIT
CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS | 12 Months Ended |
Dec. 31, 2020 | |
Equity Method Investments and Joint Ventures [Abstract] | |
CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS | CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS The Registrants may hold ownership interests in a number of business ventures with varying ownership structures. Partnership interests and other variable interests are evaluated to determine if each entity is a VIE. If a venture is a VIE for which a Registrant is the primary beneficiary, the assets, liabilities, and results of operations of the entity are consolidated. The Registrants reassess the conclusion as to whether an entity is a VIE upon certain occurrences, which are deemed reconsideration events. For entities that are not determined to be VIEs, the Registrants evaluate whether they have control or significant influence over the investee to determine the appropriate consolidation and presentation. Generally, entities under the control of a Registrant are consolidated, and entities over which a Registrant can exert significant influence, but which a Registrant does not control, are accounted for under the equity method of accounting. Investments accounted for under the equity method are recorded within equity investments in unconsolidated subsidiaries in the balance sheets and, for Southern Company and Southern Company Gas, the equity income is recorded within earnings from equity method investments in the statements of income. See "SEGCO" and "Southern Company Gas" herein for additional information. SEGCO Alabama Power and Georgia Power own equally all of the outstanding capital stock of SEGCO, which owns electric generating units with a total rated capacity of 1,020 MWs, as well as associated transmission facilities. Alabama Power and Georgia Power account for SEGCO using the equity method; Southern Company consolidates SEGCO. The capacity of these units is sold equally to Alabama Power and Georgia Power. Alabama Power and Georgia Power make payments sufficient to provide for the operating expenses, taxes, interest expense, and a ROE. The share of purchased power included in purchased power, affiliates in the statements of income totaled $67 million in 2020, $93 million in 2019, and $102 million in 2018 for Alabama Power and $69 million in 2020, $95 million in 2019, and $105 million in 2018 for Georgia Power. SEGCO paid dividends of $12 million in 2020, $14 million in 2019, and $18 million in 2018, one half of which were paid to each of Alabama Power and Georgia Power. In addition, Alabama Power and Georgia Power each recognize 50% of SEGCO's net income. Alabama Power, which owns and operates a generating unit adjacent to the SEGCO generating units, has a joint ownership agreement with SEGCO for the ownership of an associated gas pipeline. Alabama Power owns 14% of the pipeline with the remaining 86% owned by SEGCO. See Note 3 under "Guarantees" for additional information regarding guarantees of Alabama Power and Georgia Power related to SEGCO. Southern Power Variable Interest Entities Southern Power has certain subsidiaries that are determined to be VIEs. Southern Power is considered the primary beneficiary of these VIEs because it controls the most significant activities of the VIEs, including operating and maintaining the respective assets, and has the obligation to absorb expected losses of these VIEs to the extent of its equity interests. SP Solar and SP Wind In 2018, Southern Power sold a noncontrolling 33% limited partnership interest in SP Solar to Global Atlantic Financial Group Limited (Global Atlantic). See Note 15 under "Southern Power" for additional information. A wholly-owned subsidiary of Southern Power is the general partner and holds a 1% ownership interest in SP Solar and another wholly-owned subsidiary of Southern Power owns the remaining 66% ownership in SP Solar. SP Solar qualifies as a VIE since the arrangement is structured as a limited partnership and the 33% limited partner does not have substantive kick-out rights against the general partner. At December 31, 2020 and 2019, SP Solar had total assets of $6.1 billion and $6.4 billion, respectively, total liabilities of $387 million and $381 million, respectively, and noncontrolling interests of $1.1 billion. Cash distributions from SP Solar are allocated 67% to Southern Power and 33% to Global Atlantic in accordance with their partnership interest percentage. Under the terms of the limited partnership agreement, distributions without limited partner consent are limited to available cash and SP Solar is obligated to distribute all such available cash to its partners each quarter. Available cash includes all cash generated in the quarter subject to the maintenance of appropriate operating reserves. In 2018, Southern Power sold a noncontrolling tax-equity interest in SP Wind to three financial investors. SP Wind owns eight operating wind farms. See Note 15 under "Southern Power" for additional information. Southern Power owns 100% of the Class B membership interests and the three financial investors own 100% of the Class A membership interests. SP Wind qualifies as a VIE since the structure of the arrangement is similar to a limited partnership and the Class A members do not have substantive kick-out rights against Southern Power. At December 31, 2020 and 2019, SP Wind had total assets of $2.4 billion and $2.5 billion, respectively, total liabilities of $138 million and $128 million, respectively, and noncontrolling interests of $43 million and $45 million, respectively. Under the terms of the limited liability agreement, distributions without Class A member consent are limited to available cash and SP Wind is obligated to distribute all such available cash to its members each quarter. Available cash includes all cash generated in the quarter subject to the maintenance of appropriate operating reserves. Cash distributions from SP Wind are generally allocated 60% to Southern Power and 40% to the three financial investors in accordance with the limited liability agreement. Southern Power consolidates both SP Solar and SP Wind, as the primary beneficiary, since it controls the most significant activities of each entity, including operating and maintaining their assets. Certain transfers and sales of the assets in the VIEs are subject to partner consent and the liabilities are non-recourse to the general credit of Southern Power. Liabilities consist of customary working capital items and do not include any long-term debt. Other Variable Interest Entities Southern Power has other consolidated VIEs that relate to certain subsidiaries that have either sold noncontrolling interests to tax-equity investors or acquired less than a 100% interest from facility developers. These entities are considered VIEs because the arrangements are structured similar to a limited partnership and the noncontrolling members do not have substantive kick-out rights. At December 31, 2020 and 2019, the other VIEs had total assets of $1.1 billion, total liabilities of $110 million and $104 million, respectively, and noncontrolling interests of $454 million and $409 million, respectively. Under the terms of the partnership agreements, distributions of all available cash are required each month or quarter and additional distributions require partner consent. Equity Method Investments At December 31, 2020 and 2019, Southern Power had equity method investments in wind and battery storage projects totaling $19 million and $28 million, respectively. Southern Company Gas Equity Method Investments The carrying amounts of Southern Company Gas' equity method investments at December 31, 2020 and 2019 and related income from those investments for the years ended December 31, 2020, 2019, and 2018 were as follows: Investment Balance 2020 2019 (a) (in millions) SNG (b) $ 1,167 $ 1,137 PennEast Pipeline (c) 91 82 Other 32 32 Total $ 1,290 $ 1,251 (a) Excludes investments in Atlantic Coast Pipeline and Pivotal JAX LNG classified as held for sale at December 31, 2019. See Note 15 under "Assets Held for Sale" for additional information. (b) Increase primarily relates to a capital contribution, partially offset by the continued amortization of deferred tax assets established upon acquisition. (c) See Note 3 under "Other Matters – Southern Company Gas" for additional information. Earnings from Equity Method Investments 2020 2019 2018 (in millions) SNG $ 129 $ 141 $ 131 Atlantic Coast Pipeline (a)(b) 3 13 7 PennEast Pipeline (a) 7 6 5 Other (c) 2 (3) 5 Total $ 141 $ 157 $ 148 (a) Earnings primarily result from AFUDC equity recorded by the project entity. (b) On March 24, 2020, Southern Company Gas completed the sale of its interest in Atlantic Coast Pipeline. See Note 15 under "Southern Company Gas" for additional information. (c) In May 2019, Southern Company Gas sold its investment in Triton, a cargo container leasing company that was aggregated into Southern Company Gas' all other segment. On March 24, 2020, Southern Company Gas completed the sale of its interest in Pivotal LNG. See Note 15 under "Southern Company Gas" for additional information. |
FINANCING
FINANCING | 12 Months Ended |
Dec. 31, 2020 | |
Debt Disclosure [Abstract] | |
FINANCING | FINANCING Long-term Debt Details of long-term debt at December 31, 2020 and 2019 are provided in the following table: At December 31, 2020 Balance Outstanding at Maturity Weighted Average 2020 2019 (in millions) Southern Company Senior notes (a) 2021-2050 3.78% $ 30,850 $ 30,023 Junior subordinated notes 2024-2080 4.30% 7,295 5,295 FFB loans (b) 2021-2044 2.92% 4,618 3,843 Pollution control revenue bonds (c) 2021-2053 1.11% 2,675 2,963 First mortgage bonds (d) 2023-2060 3.71% 1,900 1,575 Other revenue bonds (e) 2021-2040 6.45% 320 320 Debt payable to affiliated trusts (f) 2042 3.33% 206 206 Medium-term notes 2021-2027 7.88% 160 160 Other long-term debt 2021-2023 0.83% 370 145 Finance lease obligations (g) 231 226 Unamortized fair value adjustment 393 430 Unamortized debt premium (discount), net (201) (152) Unamortized debt issuance expenses (237) (247) Total long-term debt 48,580 44,787 Less: Amount due within one year 3,507 2,989 Total long-term debt excluding amount due within one year $ 45,073 $ 41,798 Alabama Power Senior notes 2021-2049 4.03% $ 7,625 $ 7,275 Pollution control revenue bonds (c) 2021-2038 0.53% 1,060 1,060 Debt payable to affiliated trusts (f) 2042 3.33% 206 206 Other long-term debt 2021 1.20% 45 45 Finance lease obligations (g) 5 4 Unamortized debt premium (discount), net (16) (14) Unamortized debt issuance expenses (56) (55) Total long-term debt 8,869 8,521 Less: Amount due within one year 311 251 Total long-term debt excluding amount due within one year $ 8,558 $ 8,270 Georgia Power Senior notes 2021-2050 3.59% $ 6,400 $ 5,850 Junior subordinated notes 2077 5.00% 270 270 FFB loans (b) 2021-2044 2.92% 4,618 3,843 Pollution control revenue bonds (c) 2025-2053 1.47% 1,538 1,821 Other long-term debt 2021 0.65% 125 — Finance lease obligations (g) 145 156 Unamortized debt premium (discount), net (12) (7) Unamortized debt issuance expenses (114) (117) Total long-term debt 12,970 11,816 Less: Amount due within one year 542 1,025 Total long-term debt excluding amount due within one year $ 12,428 $ 10,791 At December 31, 2020 Balance Outstanding at Maturity Weighted Average 2020 2019 (in millions) Mississippi Power Senior notes 2028-2042 4.23% $ 900 $ 1,175 Pollution control revenue bonds (c) 2025-2028 1.86% 76 83 Other revenue bonds (e) 2021-2040 6.45% 320 320 Other long-term debt 2021-2023 1.00% 100 — Finance lease obligations (g) 19 — Unamortized debt premium (discount), net 11 19 Unamortized debt issuance expenses (7) (8) Total long-term debt 1,419 1,589 Less: Amount due within one year 406 281 Total long-term debt excluding amount due within one year $ 1,013 $ 1,308 Southern Power Senior notes (a) 2021-2046 3.96% $ 3,714 $ 4,425 Unamortized debt premium (discount), net (6) (8) Unamortized debt issuance expenses (16) (19) Total long-term debt 3,692 4,398 Less: Amount due within one year 299 824 Total long-term debt excluding amount due within one year $ 3,393 $ 3,574 Southern Company Gas Senior notes 2021-2047 4.01% $ 4,200 $ 3,700 First mortgage bonds (d) 2023-2060 3.71% 1,900 1,575 Medium-term notes 2021-2027 7.88% 160 160 Unamortized fair value adjustment 393 430 Unamortized debt premium (discount), net (27) (20) Total long-term debt 6,626 5,845 Less: Amount due within one year 333 — Total long-term debt excluding amount due within one year $ 6,293 $ 5,845 (a) Includes a fair value gain (loss) of $109 million and $(5) million at December 31, 2020 and 2019, respectively, related to Southern Power's foreign currency hedge on its €1.1 billion senior notes. (b) Secured by a first priority lien on (i) Georgia Power's 45.7% undivided ownership interest in Plant Vogtle Units 3 and 4 (primarily the units under construction, the related real property, and any nuclear fuel loaded in the reactor core) and (ii) Georgia Power's rights and obligations under the principal contracts relating to Plant Vogtle Units 3 and 4. See "DOE Loan Guarantee Borrowings" for additional information. (c) Pollution control revenue bond obligations represent loans to the traditional electric operating companies from public authorities of funds derived from sales by such authorities of revenue bonds issued to finance pollution control and solid waste disposal facilities. In some cases, the pollution control revenue bond obligations represent obligations under installment sales agreements with respect to facilities constructed with the proceeds of revenue bonds issued by public authorities. The traditional electric operating companies are required to make payments sufficient for the authorities to meet principal and interest requirements of such bonds. Proceeds from certain issuances are restricted until qualifying expenditures are incurred. (d) Secured by substantially all of Nicor Gas' properties. (e) At December 31, 2020 and 2019, Mississippi Power had $270 million aggregate principal amount outstanding of Mississippi Business Finance Corporation Taxable Revenue Bonds, 7.13% Series 1999A due October 20, 2021, which are secured by Plant Daniel Units 3 and 4 and certain related personal property. Mississippi Power assumed the obligations in 2011 in connection with its election under its operating lease of Plant Daniel Units 3 and 4 to purchase the assets and recorded the bonds at fair value. At December 31, 2020 and 2019, Mississippi Power also had $50 million of tax-exempt revenue bond obligations outstanding representing loans to Mississippi Power through the Mississippi Business Finance Corporation issued to finance a portion of the costs of constructing the Kemper County energy facility. (f) Alabama Power has formed a wholly-owned trust subsidiary for the purpose of issuing preferred securities. The proceeds of the related equity investments and preferred security sales were loaned back to Alabama Power through the issuance of junior subordinated notes, which constitute substantially all of the assets of this trust. Alabama Power considers that the mechanisms and obligations relating to the preferred securities issued for its benefit, taken together, constitute a full and unconditional guarantee by it of the trust's payment obligations with respect to these securities. See Note 1 under "Variable Interest Entities" for additional information on the accounting treatment for this trust and the related securities. (g) Secured by the underlying lease ROU asset. See Note 9 for additional information. Maturities of long-term debt for the next five years are as follows: Southern Company (a) Alabama Power Georgia Power (b) Mississippi Power (c) Southern Power (d) Southern Company (in millions) 2021 $ 3,506 $ 311 $ 542 $ 406 $ 300 $ 330 2022 3,707 751 488 16 677 46 2023 3,131 301 889 1 290 400 2024 509 22 491 1 — — 2025 1,191 250 138 12 500 300 (a) Amount for 2022 includes junior subordinated notes totaling $1.725 billion at the parent entity with final maturity dates in 2024 and 2027 (one half in each year); however, in connection with related stock purchase contracts, Southern Company has agreed to remarket the notes in 2022. See "Equity Units" herein for additional information. Also see notes (b), (c), and (d) below. (b) Amounts include principal amortization related to the FFB borrowings; however, the final maturity date is February 20, 2044. See "DOE Loan Guarantee Borrowings" herein for additional information. (c) Amount for 2021 includes $50 million and $25 million of long-term debt with final maturity dates in 2040 and 2023, respectively, that Mississippi Power intends to repay in 2021. (d) Southern Power's 2022 maturity represents euro-denominated debt at the U.S. dollar denominated hedge settlement amount. DOE Loan Guarantee Borrowings Pursuant to the loan guarantee program established under Title XVII of the Energy Policy Act of 2005 (Title XVII Loan Guarantee Program), Georgia Power and the DOE entered into a loan guarantee agreement in 2014 and the Amended and Restated Loan Guarantee Agreement in March 2019. Under the Amended and Restated Loan Guarantee Agreement, the DOE agreed to guarantee the obligations of Georgia Power under the FFB Credit Facilities. Under the FFB Credit Facilities, Georgia Power may make term loan borrowings through the FFB in an amount up to approximately $5.130 billion, provided that total aggregate borrowings under the FFB Credit Facilities may not exceed 70% of (i) Eligible Project Costs minus (ii) approximately $1.492 billion (reflecting the amounts received by Georgia Power under the Guarantee Settlement Agreement less the related customer refunds). In June and December 2020, Georgia Power made borrowings under the FFB Credit Facilities in an aggregate principal amount of $519 million and $329 million, respectively, at an interest rate of 1.652% and 1.737%, respectively, through the final maturity date of February 20, 2044. During 2020, Georgia Power made principal amortization payments of $73 million under the FFB Credit Facilities. At December 31, 2020 and 2019, Georgia Power had $4.6 billion and $3.8 billion of borrowings outstanding under the FFB Credit Facilities, respectively. All borrowings under the FFB Credit Facilities are full recourse to Georgia Power, and Georgia Power is obligated to reimburse the DOE for any payments the DOE is required to make to the FFB under its guarantee. Georgia Power's reimbursement obligations to the DOE are full recourse and secured by a first priority lien on (i) Georgia Power's 45.7% undivided ownership interest in Plant Vogtle Units 3 and 4 (primarily the units under construction, the related real property, and any nuclear fuel loaded in the reactor core) and (ii) Georgia Power's rights and obligations under the principal contracts relating to Plant Vogtle Units 3 and 4. There are no restrictions on Georgia Power's ability to grant liens on other property. In addition to the conditions described above, future advances are subject to satisfaction of customary conditions, as well as certification of compliance with the requirements of the Title XVII Loan Guarantee Program, including accuracy of project-related representations and warranties, delivery of updated project-related information, and evidence of compliance with the prevailing wage requirements of the Davis-Bacon Act of 1931, as amended, and certification from the DOE's consulting engineer that proceeds of the advances are used to reimburse Eligible Project Costs. Upon satisfaction of all conditions described above, advances may be requested on a quarterly basis through 2023. The final maturity date for each advance under the FFB Credit Facilities is February 20, 2044. Interest is payable quarterly and principal payments began on February 20, 2020. Borrowings under the FFB Credit Facilities will bear interest at the applicable U.S. Treasury rate plus a spread equal to 0.375%. Under the Amended and Restated Loan Guarantee Agreement, Georgia Power is subject to customary borrower affirmative and negative covenants and events of default. In addition, Georgia Power is subject to project-related reporting requirements and other project-specific covenants and events of default. In the event certain mandatory prepayment events occur, the FFB's commitment to make further advances under the FFB Credit Facilities will terminate and Georgia Power will be required to prepay the outstanding principal amount of all borrowings under the FFB Credit Facilities over a period of five years (with level principal amortization). Among other things, these mandatory prepayment events include (i) the termination of the Vogtle Services Agreement or rejection of the Vogtle Services Agreement in any Westinghouse bankruptcy if Georgia Power does not maintain access to intellectual property rights under the related intellectual property licenses; (ii) termination of the Bechtel Agreement, unless the Vogtle Owners enter into a replacement agreement; (iii) cancellation of Plant Vogtle Units 3 and 4 by the Georgia PSC or by Georgia Power; (iv) failure of the holders of 90% of the ownership interests in Plant Vogtle Units 3 and 4 to vote to continue construction following certain schedule extensions; (v) cost disallowances by the Georgia PSC that could have a material adverse effect on completion of Plant Vogtle Units 3 and 4 or Georgia Power's ability to repay the outstanding borrowings under the FFB Credit Facilities; or (vi) loss of or failure to receive necessary regulatory approvals. Under certain circumstances, insurance proceeds and any proceeds from an event of taking must be applied to immediately prepay outstanding borrowings under the FFB Credit Facilities. Georgia Power also may voluntarily prepay outstanding borrowings under the FFB Credit Facilities. Under the FFB Credit Facilities, any prepayment (whether mandatory or optional) will be made with a make-whole premium or discount, as applicable. In connection with any cancellation of Plant Vogtle Units 3 and 4, the DOE may elect to continue construction of Plant Vogtle Units 3 and 4. In such an event, the DOE will have the right to assume Georgia Power's rights and obligations under the principal agreements relating to Plant Vogtle Units 3 and 4 and to acquire all or a portion of Georgia Power's ownership interest in Plant Vogtle Units 3 and 4. Secured Debt Each of Southern Company's subsidiaries is organized as a legal entity, separate and apart from Southern Company and its other subsidiaries. There are no agreements or other arrangements among the Southern Company system companies under which the assets of one company have been pledged or otherwise made available to satisfy obligations of Southern Company or any of its other subsidiaries. As discussed under "Long-term Debt" herein, the Registrants had secured debt outstanding at December 31, 2020 and 2019. Each Registrant's senior notes, junior subordinated notes, pollution control and other revenue bond obligations, bank term loans, credit facility borrowings, and notes payable are effectively subordinated to all secured debt of each respective Registrant. Equity Units In August 2019, Southern Company issued 34.5 million 2019 Series A Equity Units (Equity Units), initially in the form of corporate units (Corporate Units), at a stated amount of $50 per Corporate Unit, for a total stated amount of $1.725 billion. Net proceeds from the issuance were approximately $1.682 billion. The proceeds were used to repay short-term indebtedness and for other general corporate purposes, including investments in Southern Company's subsidiaries. Each Corporate Unit is comprised of (i) a 1/40 undivided beneficial ownership interest in $1,000 principal amount of Southern Company's Series 2019A Remarketable Junior Subordinated Notes (Series 2019A RSNs) due 2024, (ii) a 1/40 undivided beneficial ownership interest in $1,000 principal amount of Southern Company's Series 2019B Remarketable Junior Subordinated Notes (together with the Series 2019A RSNs, the RSNs) due 2027, and (iii) a stock purchase contract, which obligates the holder to purchase from Southern Company, no later than August 1, 2022, a certain number of shares of Southern Company's common stock for $50 in cash (Stock Purchase Contract). Southern Company has agreed to remarket the RSNs in 2022, at which time each interest rate on the RSNs will reset at the applicable market rate. Holders may choose to either remarket their RSNs, receive the proceeds, and use those funds to settle the related Stock Purchase Contract or retain the RSNs and use other funds to settle the related Stock Purchase Contract. If the remarketing is unsuccessful, holders will have the right to put their RSNs to Southern Company at a price equal to the principal amount. The Corporate Units carry an annual distribution rate of 6.75% of the stated amount, which is comprised of a quarterly interest payment on the RSNs of 2.70% per year and a quarterly purchase contract adjustment payment of 4.05% per year. Each Stock Purchase Contract obligates the holder to purchase, and Southern Company to sell, for $50 a number of shares of Southern Company common stock determined based on the applicable market value (as determined under the related Stock Purchase Contract) in accordance with the conversion ratios set forth below (subject to anti-dilution adjustments): • If the applicable market value is equal to or greater than $68.64, 0.7284 shares. • If the applicable market value is less than $68.64 but greater than $57.20, a number of shares equal to $50 divided by the applicable market value. • If the applicable market value is less than or equal to $57.20, 0.8741 shares. Bank Credit Arrangements At December 31, 2020, committed credit arrangements with banks were as follows: Expires Company 2021 2022 2023 2024 Total Unused Due within (in millions) Southern Company parent $ — $ — $ — $ 2,000 $ 2,000 $ 1,999 $ — Alabama Power 3 525 — 800 1,328 1,328 3 Georgia Power — — — 1,750 1,750 1,728 — Mississippi Power — 150 125 — 275 250 — Southern Power (a) — — — 600 600 591 — Southern Company Gas (b) — — — 1,750 1,750 1,745 — SEGCO 30 — — — 30 30 30 Southern Company $ 33 $ 675 $ 125 $ 6,900 $ 7,733 $ 7,671 $ 33 (a) Does not include Southern Power Company's $75 million and $60 million continuing letter of credit facilities for standby letters of credit expiring in 2023, of which $5 million and $11 million, respectively, was unused at December 31, 2020. In December 2020, Southern Power amended its $120 million letter of credit facility, which, among other things, extended the expiration date from 2021 to 2023 and reduced the amount to $75 million. Southern Power's subsidiaries are not parties to its bank credit arrangements or letter of credit facilities. (b) Southern Company Gas, as the parent entity, guarantees the obligations of Southern Company Gas Capital, which is the borrower of $1.25 billion of this arrangement. Southern Company Gas' committed credit arrangement also includes $500 million for which Nicor Gas is the borrower and which is restricted for working capital needs of Nicor Gas. Pursuant to this multi-year credit arrangement, the allocations between Southern Company Gas Capital and Nicor Gas may be adjusted. See "Structural Considerations" herein for additional information. The bank credit arrangements require payment of commitment fees based on the unused portion of the commitments. Commitment fees average less than 1 / 4 of 1% for the Registrants and Nicor Gas. Subject to applicable market conditions, Southern Company and its subsidiaries expect to renew or replace their bank credit arrangements as needed, prior to expiration. In connection therewith, Southern Company and its subsidiaries may extend the maturity dates and/or increase or decrease the lending commitments thereunder. These bank credit arrangements, as well as the term loan arrangements of the Registrants and SEGCO, contain covenants that limit debt levels and contain cross-acceleration or, in the case of Southern Power, cross-default provisions to other indebtedness (including guarantee obligations) that are restricted only to the indebtedness of the individual company. Such cross-default provisions to other indebtedness would trigger an event of default if Southern Power defaulted on indebtedness or guarantee obligations over a specified threshold. Such cross-acceleration provisions to other indebtedness would trigger an event of default if the applicable borrower defaulted on indebtedness, the payment of which was then accelerated. Southern Company's, Southern Company Gas', and Nicor Gas' credit arrangements contain covenants that limit debt levels to 70% of total capitalization, as defined in the agreements, and the other subsidiaries' bank credit arrangements contain covenants that limit debt levels to 65% of total capitalization, as defined in the agreements. For purposes of these definitions, debt excludes the long-term debt payable to affiliated trusts and, in certain arrangements, other hybrid securities. Additionally, for Southern Company and Southern Power, for purposes of these definitions, debt excludes any project debt incurred by certain subsidiaries of Southern Power to the extent such debt is non-recourse to Southern Power and capitalization excludes the capital stock or other equity attributable to such subsidiaries. At December 31, 2020, the Registrants, Nicor Gas, and SEGCO were in compliance with all such covenants. None of the bank credit arrangements contain material adverse change clauses at the time of borrowings. A portion of the unused credit with banks is allocated to provide liquidity support to the revenue bonds of the traditional electric operating companies and the commercial paper programs of the Registrants and Nicor Gas. The amount of variable rate revenue bonds of the traditional electric operating companies outstanding requiring liquidity support at December 31, 2020 was approximately $1.4 billion (comprised of approximately $854 million at Alabama Power, $550 million at Georgia Power, and $34 million at Mississippi Power). In addition, at December 31, 2020, Georgia Power and Mississippi Power had approximately $174 million and $50 million, respectively, of fixed rate revenue bonds outstanding that are required to be remarketed within the next 12 months. At December 31, 2020 and 2019, Southern Power had $105 million and $104 million, respectively, of cash collateral posted related to PPA requirements, which is included in other deferred charges and assets on Southern Power's consolidated balance sheets. Notes Payable The Registrants, Nicor Gas, and SEGCO make short-term borrowings primarily through commercial paper programs that have the liquidity support of the committed bank credit arrangements described above under "Bank Credit Arrangements." Southern Power's subsidiaries are not parties or obligors to its commercial paper program. Southern Company Gas maintains commercial paper programs at Southern Company Gas Capital and at Nicor Gas. Nicor Gas' commercial paper program supports working capital needs at Nicor Gas as Nicor Gas is not permitted to make money pool loans to affiliates. All of Southern Company Gas' other subsidiaries benefit from Southern Company Gas Capital's commercial paper program. See "Structural Considerations" herein for additional information. In addition, Southern Company and certain of its subsidiaries have entered into various bank term loan agreements. Unless otherwise stated, the proceeds of these loans were used to repay existing indebtedness and for general corporate purposes, including working capital and, for the subsidiaries, their continuous construction programs. Commercial paper and short-term bank term loans are included in notes payable in the balance sheets. Details of short-term borrowings for the applicable Registrants were as follows: Notes Payable at December 31, 2020 Notes Payable at December 31, 2019 Amount Weighted Average Amount Weighted Average (in millions) (in millions) Southern Company Commercial paper $ 609 0.3 % $ 1,705 2.1 % Short-term bank debt — — % 350 2.3 % Total $ 609 0.3 % $ 2,055 2.1 % Georgia Power Commercial paper $ 60 0.3 % $ 115 2.1 % Short-term bank debt — — % 250 2.2 % Total $ 60 0.3 % $ 365 2.2 % Mississippi Power Commercial paper $ 25 0.4 % $ — — % Southern Power Commercial paper $ 175 0.3 % $ 449 2.1 % Short-term bank debt — — % 100 2.6 % Total $ 175 0.3 % $ 549 2.2 % Southern Company Gas Commercial paper: Southern Company Gas Capital $ 220 0.3 % $ 372 2.1 % Nicor Gas 104 0.2 % 278 1.8 % Total $ 324 0.2 % $ 650 2.0 % See "Bank Credit Arrangements" herein for information on bank term loan covenants that limit debt levels and cross-acceleration or cross-default provisions. Southern Company Common Stock Stock Issued During 2020, Southern Company issued approximately 3.3 million shares of common stock through employee equity compensation plans and received proceeds of approximately $74 million. See "Equity Units" herein for additional information. Shares Reserved At December 31, 2020, a total of 88 million shares were reserved for issuance pursuant to the Southern Investment Plan, employee savings plans, the Outside Directors Stock Plan, the Omnibus Incentive Compensation Plan (which includes stock options and performance share units as discussed in Note 12), and an at-the-market program. Of the total 88 million shares reserved, 6.8 million shares are available for awards under the Omnibus Incentive Compensation Plan at December 31, 2020. Diluted Earnings Per Share For Southern Company, the only differences in computing basic and diluted earnings per share (EPS) are attributable to awards outstanding under stock-based compensation plans and the Equity Units. Earnings per share dilution resulting from stock-based compensation plans and the Equity Units issuance is determined using the treasury stock method. Shares used to compute diluted EPS were as follows: Average Common Stock Shares 2020 2019 2018 (in millions) As reported shares 1,058 1,046 1,020 Effect of stock-based compensation 7 8 5 Diluted shares 1,065 1,054 1,025 In all years presented, an immaterial number of stock-based compensation awards was not included in the diluted EPS calculation because the awards were anti-dilutive. The Equity Units were excluded from the calculation of diluted EPS for 2020 and 2019 as the dilutive stock price threshold was not met. Redeemable Preferred Stock of Subsidiaries As discussed further under "Alabama Power" herein, the preferred stock of Alabama Power is presented as "Redeemable Preferred Stock of Subsidiaries" on Southern Company's balance sheets in a manner consistent with temporary equity under applicable accounting standards. In 2018, Mississippi Power completed the redemption of all outstanding shares and depository shares of its redeemable preferred stock totaling $33 million, as described further under "Mississippi Power" herein. Alabama Power Alabama Power has preferred stock, Class A preferred stock, and common stock outstanding. Alabama Power also has authorized preference stock, none of which is outstanding. Alabama Power's preferred stock and Class A preferred stock, without preference between classes, rank senior to Alabama Power's common stock with respect to payment of dividends and voluntary and involuntary dissolution. The preferred stock and Class A preferred stock of Alabama Power contain a feature that allows the holders to elect a majority of Alabama Power's board of directors if preferred dividends are not paid for four consecutive quarters. Because such a potential redemption-triggering event is not solely within the control of Alabama Power, the preferred stock and Class A preferred stock is presented as "Redeemable Preferred Stock" on Alabama Power's balance sheets in a manner consistent with temporary equity under applicable accounting standards. Alabama Power's preferred stock is subject to redemption at a price equal to the par value plus a premium. Alabama Power's Class A preferred stock is subject to redemption at a price equal to the stated capital. All series of Alabama Power's preferred stock currently are subject to redemption at the option of Alabama Power. The Class A preferred stock is subject to redemption on or after October 1, 2022, or following the occurrence of a rating agency event. Information for each outstanding series is in the table below: Preferred Stock Par Value/Stated Capital Per Share Shares Outstanding Redemption 4.92% Preferred Stock $100 80,000 $103.23 4.72% Preferred Stock $100 50,000 $102.18 4.64% Preferred Stock $100 60,000 $103.14 4.60% Preferred Stock $100 100,000 $104.20 4.52% Preferred Stock $100 50,000 $102.93 4.20% Preferred Stock $100 135,115 $105.00 5.00% Class A Preferred Stock $25 10,000,000 $25.00 (*) Georgia Power Georgia Power has preferred stock, Class A preferred stock, preference stock, and common stock authorized, but only common stock outstanding as of December 31, 2020 and 2019. Mississippi Power Mississippi Power has preferred stock and common stock authorized, but only common stock outstanding as of December 31, 2020 and 2019. In 2018, Mississippi Power completed the redemption of all outstanding shares and depository shares of its Preferred Stock. Dividend Restrictions The income of Southern Company is derived primarily from equity in earnings of its subsidiaries. At December 31, 2020, consolidated retained earnings included $5.6 billion of undistributed retained earnings of the subsidiaries. The traditional electric operating companies and Southern Power can only pay dividends to Southern Company out of retained earnings or paid-in-capital. See Note 7 under "Southern Power" for information regarding the distribution requirements for certain Southern Power subsidiaries. By regulation, Nicor Gas is restricted, to the extent of its retained earnings balance, in the amount it can dividend or loan to affiliates and is not permitted to make money pool loans to affiliates. At December 31, 2020, the amount of Southern Company Gas' subsidiary retained earnings restricted for dividend payment totaled $1.1 billion. Structural Considerations Since Southern Company and Southern Company Gas are holding companies, the right of Southern Company and Southern Company Gas and, hence, the right of creditors of Southern Company or Southern Company Gas to participate in any distribution of the assets of any respective subsidiary of Southern Company or Southern Company Gas, whether upon liquidation, reorganization or otherwise, is subject to prior claims of creditors and preferred stockholders of such subsidiary. Southern Company Gas' 100%-owned subsidiary, Southern Company Gas Capital, was established to provide for certain of Southern Company Gas' ongoing financing needs through a commercial paper program, the issuance of various debt, hybrid securities, and other financing arrangements. Southern Company Gas fully and unconditionally guarantees all debt issued by Southern Company Gas Capital. Nicor Gas is not permitted by regulation to make loans to affiliates or utilize Southern Company Gas Capital for its financing needs. Southern Power Company's senior notes, bank term loan, commercial paper, and bank credit arrangement are unsecured senior indebtedness, which rank equally with all other unsecured and unsubordinated debt of Southern Power Compan y. Southern Power's subsidiaries are not issuers, borrowers, or obligors, as applicable, under any of these unsecured senior debt arrangements, which are effectively subordinated to any future secured debt of Southern Power Company and any potential claims of creditors of Southern Power's subsidiaries. |
LEASES
LEASES | 12 Months Ended |
Dec. 31, 2020 | |
Leases [Abstract] | |
LEASES | LEASES On January 1, 2019, the Registrants adopted the provisions of FASB ASC Topic 842 (as amended), Leases (ASC 842), which require lessees to recognize leases with a term of greater than 12 months on the balance sheet as lease obligations, representing the discounted future fixed payments due, along with ROU assets that will be amortized over the term of each lease. The Registrants elected the transition methodology provided by ASC 842, whereby the applicable requirements were applied on a prospective basis as of the adoption date of January 1, 2019, without restating prior periods. The Registrants also elected the package of practical expedients provided by ASC 842 that allows prior determinations of whether existing contracts are, or contain, leases and the classification of existing leases to continue without reassessment. Additionally, the Registrants applied the use-of-hindsight practical expedient in determining lease terms as of the date of adoption and elected the practical expedient that allows existing land easements not previously accounted for as leases not to be reassessed. Lessee As lessee, the Registrants lease certain electric generating units (including renewable energy facilities), real estate/land, communication towers, railcars, and other equipment and vehicles. The major categories of lease obligations are as follows: Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) As of December 31, 2020 Electric generating units $ 941 $ 146 $ 1,368 $ — $ — $ — Real estate/land 815 4 53 2 451 61 Communication towers 158 2 3 — — 20 Railcars 42 16 23 3 — — Other 127 7 5 23 — 1 Total $ 2,083 $ 175 $ 1,452 $ 28 $ 451 $ 82 As of December 31, 2019 Electric generating units $ 990 $ 125 $ 1,487 $ — $ — $ — Real estate/land 782 4 54 2 398 74 Communication towers 154 2 3 — — 18 Railcars 51 21 26 3 — — Other 93 8 12 1 — — Total $ 2,070 $ 160 $ 1,582 $ 6 $ 398 $ 92 Real estate/land leases primarily consist of commercial real estate leases at Southern Company, Georgia Power, and Southern Company Gas and various land leases primarily associated with renewable energy facilities at Southern Power. The commercial real estate leases have remaining terms of up to 24 years while the land leases have remaining terms of up to 46 years, including renewal periods. Communication towers are leased for the installation of equipment to provide cellular phone service to customers and to support the automated meter infrastructure programs at the traditional electric operating companies and Nicor Gas. Communication tower leases have original terms of up to 10 years with options to renew for periods up to 20 years. Renewal options exist in many of the leases. Except as otherwise noted, the expected term used in calculating the lease obligation generally reflects only the noncancelable period of the lease as it is not considered reasonably certain that the lease will be extended. Land leases associated with renewable energy facilities at Southern Power and communication tower leases for automated meter infrastructure at Southern Company Gas include renewal periods reasonably certain of exercise resulting in an expected lease term at least equal to the expected life of the renewable energy facilities and the automated meter infrastructure, respectively. Contracts that Contain a Lease While not specifically structured as a lease, some of the PPAs at Alabama Power and Georgia Power are deemed to represent a lease of the underlying electric generating units when the terms of the PPA convey the right to control the use of the underlying assets. Amounts recorded for leases of electric generating units are generally based on the amount of scheduled capacity payments due over the remaining term of the PPA, which varies between three Short-term Leases Leases with an initial term of 12 months or less are not recorded on the balance sheet; the Registrants generally recognize lease expense for these leases on a straight-line basis over the lease term. Residual Value Guarantees Residual value guarantees exist primarily in railcar leases at Alabama Power and Georgia Power and the amounts probable of being paid under those guarantees are included in the lease payments. All such amounts are immaterial as of December 31, 2020 and 2019. Lease and Nonlease Components For all asset categories, with the exception of electric generating units, gas pipelines, and real estate leases, the Registrants combine lease payments and any nonlease components, such as asset maintenance, for purposes of calculating the lease obligation and the right-of-use asset. Balance sheet amounts recorded for operating and finance leases are as follows: Southern Company Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) As of December 31, 2020 Operating Leases Operating lease ROU assets, net $ 1,802 $ 151 $ 1,308 $ 9 $ 415 $ 81 Operating lease obligations - current $ 241 $ 51 $ 151 $ 2 $ 25 $ 15 Operating lease obligations - non-current 1,611 119 1,156 7 426 67 Total operating lease obligations $ 1,852 $ 170 $ 1,307 $ 9 $ 451 $ 82 Finance Leases Finance lease ROU assets, net $ 218 $ 5 $ 115 $ 19 $ — $ — Finance lease obligations - current $ 17 $ 1 $ 9 $ 1 $ — $ — Finance lease obligations - non-current 214 4 136 18 — — Total finance lease obligations $ 231 $ 5 $ 145 $ 19 $ — $ — As of December 31, 2019 Operating Leases Operating lease ROU assets, net $ 1,800 $ 132 $ 1,428 $ 6 $ 369 $ 93 Operating lease obligations - current $ 229 $ 49 $ 144 $ 2 $ 22 $ 14 Operating lease obligations - non-current 1,615 107 1,282 4 376 78 Total operating lease obligations $ 1,844 $ 156 $ 1,426 $ 6 $ 398 $ 92 Finance Leases Finance lease ROU assets, net $ 216 $ 4 $ 130 $ — $ — $ — Finance lease obligations - current $ 21 $ 1 $ 11 $ — $ — $ — Finance lease obligations - non-current 205 3 145 — — — Total finance lease obligations $ 226 $ 4 $ 156 $ — $ — $ — If not presented separately on the Registrants' balance sheets, amounts related to leases are presented as follows: operating lease ROU assets, net are included in "other deferred charges and assets"; operating lease obligations are included in "other current liabilities" and "other deferred credits and liabilities," as applicable; finance lease ROU assets, net are included in "plant in service"; and finance lease obligations are included in "securities due within one year" and "long-term debt," as applicable. Lease costs for 2020 and 2019, which includes both amounts recognized as operations and maintenance expense and amounts capitalized as part of the cost of another asset, are as follows: Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) 2020 Lease cost Operating lease cost $ 309 $ 55 $ 212 $ 3 $ 29 $ 19 Finance lease cost: Amortization of ROU assets 26 1 15 — — — Interest on lease obligations 11 — 16 — — — Total finance lease cost 37 1 31 — — — Short-term lease costs 39 11 26 — — — Variable lease cost 91 4 76 — 7 — Sublease income — (1) — — — — Total lease cost $ 476 $ 70 $ 345 $ 3 $ 36 $ 19 2019 Lease cost Operating lease cost $ 310 $ 54 $ 206 $ 3 $ 28 $ 18 Finance lease cost: Amortization of ROU assets 28 1 15 — — — Interest on lease obligations 12 — 18 — — — Total finance lease cost 40 1 33 — — — Short-term lease costs 48 19 22 — — — Variable lease cost 105 6 85 — 7 — Sublease income — (1) — — — — Total lease cost $ 503 $ 79 $ 346 $ 3 $ 35 $ 18 Georgia Power has variable lease payments that are based on the amount of energy produced by certain renewable generating facilities subject to PPAs, including $39 million and $42 million in 2020 and 2019, respectively, from finance leases which are included in purchased power on Georgia Power's statements of income, $20 million of which was included in purchased power, affiliates in both 2020 and 2019. Rent expense and PPA capacity expense related to leases for 2018, prior to the adoption of ASC 842, were as follows: Southern Company (a)(b)(c) Alabama Georgia (a) Mississippi (b) Southern Power (c) Southern Company Gas (in millions) 2018: Rent expense $ 192 $ 23 $ 34 $ 4 $ 31 $ 15 PPA capacity expense 231 44 206 — — — (a) Georgia Power's energy-only solar PPAs accounted for as leases contained contingent rent expense of $72 million, of which $29 million related to solar PPAs with Southern Power. (b) Mississippi Power's energy-only solar PPAs accounted for as operating leases contained contingent rent expense of $10 million. (c) Rent expense includes contingent rent expense related to Southern Power's land leases based on wind production and escalation in the Consumer Price Index for All Urban Consumers. Other information with respect to cash and noncash activities related to leases, as well as weighted-average lease terms and discount rates, is as follows: Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) 2020 Other information Cash paid for amounts included in the measurements of lease obligations: Operating cash flows from operating leases $ 310 $ 55 $ 215 $ 3 $ 28 $ 18 Operating cash flows from finance leases 9 — 18 — — — Financing cash flows from finance leases 22 1 11 — — — ROU assets obtained in exchange for new operating lease obligations 227 63 32 — 51 4 ROU assets obtained in exchange for new finance lease obligations 10 2 — — — — 2019 Other information Cash paid for amounts included in the measurements of lease obligations: Operating cash flows from operating leases $ 323 $ 54 $ 210 $ 3 $ 27 $ 18 Operating cash flows from finance leases 10 — 19 — — — Financing cash flows from finance leases 32 1 13 — — — ROU assets obtained in exchange for new operating lease obligations 118 7 21 — 2 19 ROU assets obtained in exchange for new finance lease obligations 35 2 24 — — — Southern Alabama Georgia Mississippi Southern Power Southern Company Gas As of December 31, 2020 Weighted-average remaining lease term in years: Operating leases 14.5 7.8 9.4 6.5 32.1 9.8 Finance leases 18.2 9.7 9.5 14.9 N/A N/A Weighted-average discount rate: Operating leases 4.44 % 4.14 % 4.37 % 3.26 % 5.45 % 3.67 % Finance leases 4.79 % 3.20 % 10.81 % 2.74 % N/A N/A As of December 31, 2019 Weighted-average remaining lease term in years: Operating leases 14.2 3.1 10.2 7.0 32.8 9.9 Finance leases 18.8 12.1 10.5 N/A N/A N/A Weighted-average discount rate: Operating leases 4.53 % 3.33 % 4.46 % 4.02 % 5.66 % 3.7 % Finance leases 5.04 % 3.60 % 10.76 % N/A N/A N/A Maturities of lease liabilities are as follows: As of December 31, 2020 Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Maturity Analysis Operating leases: 2021 $ 300 $ 57 $ 205 $ 2 $ 30 $ 18 2022 287 58 202 4 25 14 2023 230 9 200 1 27 12 2024 187 6 164 1 27 11 2025 165 6 137 — 27 10 Thereafter 1,546 74 701 2 873 35 Total 2,715 210 1,609 10 1,009 100 Less: Present value discount 863 40 302 1 558 18 Operating lease obligations $ 1,852 $ 170 $ 1,307 $ 9 $ 451 $ 82 Finance leases: 2021 $ 28 $ 1 $ 24 $ 2 $ — $ — 2022 25 1 25 1 — — 2023 22 1 25 2 — — 2024 19 1 25 1 — — 2025 16 — 25 2 — — Thereafter 246 1 109 15 — — Total 356 5 233 23 — — Less: Present value discount 125 — 88 4 — — Finance lease obligations $ 231 $ 5 $ 145 $ 19 $ — $ — Payments made under PPAs at Georgia Power for energy generated from certain renewable energy facilities accounted for as operating and finance leases are considered variable lease costs and are therefore not reflected in the above maturity analysis. As of December 31, 2020, Southern Power has additional leases that have not yet commenced, as detailed in the following table: Southern Lease category Land Expected commencement date 2021 Longest lease term expiration 30 years Estimated total obligations (in millions) $12 Lessor The Registrants are each considered lessors in various arrangements that have been determined to contain a lease due to the customer's ability to control the use of the underlying asset owned by the applicable Registrant. For the traditional electric operating companies, these arrangements consist of outdoor lighting contracts accounted for as operating leases with initial terms of up to seven years, after which the contracts renew on a month-to-month basis at the customer's option. For Mississippi Power, these arrangements also include a tolling arrangement related to an electric generating unit accounted for as a sales-type lease with a remaining term of 18 years. For Southern Power, these arrangements consist of PPAs related to electric generating units, including renewable energy facilities, accounted for as operating leases with remaining terms of up to 26 years. Southern Company Gas is the lessor in operating leases related to gas pipelines with remaining terms of up to 22 years. For Southern Company, these arrangements also include PPAs related to fuel cells accounted for as operating leases with remaining terms of up to 14 years. Lease income for 2020 and 2019 is as follows: Southern Alabama Power Georgia Power Mississippi Southern Power Southern Company Gas (in millions) 2020 Lease income - interest income on sales-type leases $ 16 $ — $ — $ 12 $ — $ — Lease income - operating leases 208 45 58 2 87 35 Variable lease income 419 — — — 449 — Total lease income $ 643 $ 45 $ 58 $ 14 $ 536 $ 35 2019 Lease income - interest income on sales-type leases $ 9 $ — $ — $ 9 $ — $ — Lease income - operating leases 273 24 71 — 160 35 Variable lease income 403 — — — 434 — Total lease income $ 685 $ 24 $ 71 $ 9 $ 594 $ 35 Lease payments received under tolling arrangements and PPAs consist of either scheduled payments or variable payments based on the amount of energy produced by the underlying electric generating units. Lease income for Alabama Power and Southern Power is included in wholesale revenues. Scheduled payments to be received under outdoor lighting contracts, tolling arrangements, and PPAs accounted for as leases are presented in the following maturity analyses. No profit or loss was recognized by Mississippi Power upon commencement of a tolling arrangement accounted for as a sales-type lease during the first quarter 2019. Mississippi Power completed construction of additional leased assets under the lease during 2020 and, upon completion, the book value of $26 million was transferred from CWIP to lease receivables, of which $24 million and $2 million is included in other property and investments and other accounts and notes receivable, respectively, at December 31, 2020. The transfer represented a non-cash investing transaction for purposes of the statements of cash flows. Construction of additional leased assets is ongoing and will be transferred to a lease receivable as completed. The undiscounted cash flows to be received by Mississippi Power for in-service leased assets under the lease are as follows: At December 31, 2020 (in millions) 2021 $ 20 2022 19 2023 19 2024 18 2025 17 Thereafter 162 Total undiscounted cash flows $ 255 Lease receivable (*) 138 Difference between undiscounted cash flows and discounted cash flows $ 117 (*) Included in other current assets and other property and investments on the balance sheets. The undiscounted cash flows to be received under operating leases and contracts accounted for as operating leases (adjusted for intercompany eliminations) are as follows: At December 31, 2020 Southern Alabama Georgia Power Southern Southern Company Gas (in millions) 2021 $ 207 $ 83 $ 19 $ 86 $ 35 2022 187 76 8 87 35 2023 138 32 2 88 34 2024 106 4 — 90 33 2025 99 3 — 74 28 Thereafter 978 23 — 313 435 Total $ 1,715 $ 221 $ 29 $ 738 $ 600 Southern Power receives payments for renewable energy under PPAs accounted for as operating leases that are considered contingent rents and are therefore not reflected in the table above. Alabama Power and Southern Power allocate revenue to the nonlease components of PPAs based on the stand-alone selling price of capacity and energy. The undiscounted cash flows to be received under outdoor lighting contracts accounted for as operating leases at Mississippi Power are immaterial. |
LEASES | LEASES On January 1, 2019, the Registrants adopted the provisions of FASB ASC Topic 842 (as amended), Leases (ASC 842), which require lessees to recognize leases with a term of greater than 12 months on the balance sheet as lease obligations, representing the discounted future fixed payments due, along with ROU assets that will be amortized over the term of each lease. The Registrants elected the transition methodology provided by ASC 842, whereby the applicable requirements were applied on a prospective basis as of the adoption date of January 1, 2019, without restating prior periods. The Registrants also elected the package of practical expedients provided by ASC 842 that allows prior determinations of whether existing contracts are, or contain, leases and the classification of existing leases to continue without reassessment. Additionally, the Registrants applied the use-of-hindsight practical expedient in determining lease terms as of the date of adoption and elected the practical expedient that allows existing land easements not previously accounted for as leases not to be reassessed. Lessee As lessee, the Registrants lease certain electric generating units (including renewable energy facilities), real estate/land, communication towers, railcars, and other equipment and vehicles. The major categories of lease obligations are as follows: Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) As of December 31, 2020 Electric generating units $ 941 $ 146 $ 1,368 $ — $ — $ — Real estate/land 815 4 53 2 451 61 Communication towers 158 2 3 — — 20 Railcars 42 16 23 3 — — Other 127 7 5 23 — 1 Total $ 2,083 $ 175 $ 1,452 $ 28 $ 451 $ 82 As of December 31, 2019 Electric generating units $ 990 $ 125 $ 1,487 $ — $ — $ — Real estate/land 782 4 54 2 398 74 Communication towers 154 2 3 — — 18 Railcars 51 21 26 3 — — Other 93 8 12 1 — — Total $ 2,070 $ 160 $ 1,582 $ 6 $ 398 $ 92 Real estate/land leases primarily consist of commercial real estate leases at Southern Company, Georgia Power, and Southern Company Gas and various land leases primarily associated with renewable energy facilities at Southern Power. The commercial real estate leases have remaining terms of up to 24 years while the land leases have remaining terms of up to 46 years, including renewal periods. Communication towers are leased for the installation of equipment to provide cellular phone service to customers and to support the automated meter infrastructure programs at the traditional electric operating companies and Nicor Gas. Communication tower leases have original terms of up to 10 years with options to renew for periods up to 20 years. Renewal options exist in many of the leases. Except as otherwise noted, the expected term used in calculating the lease obligation generally reflects only the noncancelable period of the lease as it is not considered reasonably certain that the lease will be extended. Land leases associated with renewable energy facilities at Southern Power and communication tower leases for automated meter infrastructure at Southern Company Gas include renewal periods reasonably certain of exercise resulting in an expected lease term at least equal to the expected life of the renewable energy facilities and the automated meter infrastructure, respectively. Contracts that Contain a Lease While not specifically structured as a lease, some of the PPAs at Alabama Power and Georgia Power are deemed to represent a lease of the underlying electric generating units when the terms of the PPA convey the right to control the use of the underlying assets. Amounts recorded for leases of electric generating units are generally based on the amount of scheduled capacity payments due over the remaining term of the PPA, which varies between three Short-term Leases Leases with an initial term of 12 months or less are not recorded on the balance sheet; the Registrants generally recognize lease expense for these leases on a straight-line basis over the lease term. Residual Value Guarantees Residual value guarantees exist primarily in railcar leases at Alabama Power and Georgia Power and the amounts probable of being paid under those guarantees are included in the lease payments. All such amounts are immaterial as of December 31, 2020 and 2019. Lease and Nonlease Components For all asset categories, with the exception of electric generating units, gas pipelines, and real estate leases, the Registrants combine lease payments and any nonlease components, such as asset maintenance, for purposes of calculating the lease obligation and the right-of-use asset. Balance sheet amounts recorded for operating and finance leases are as follows: Southern Company Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) As of December 31, 2020 Operating Leases Operating lease ROU assets, net $ 1,802 $ 151 $ 1,308 $ 9 $ 415 $ 81 Operating lease obligations - current $ 241 $ 51 $ 151 $ 2 $ 25 $ 15 Operating lease obligations - non-current 1,611 119 1,156 7 426 67 Total operating lease obligations $ 1,852 $ 170 $ 1,307 $ 9 $ 451 $ 82 Finance Leases Finance lease ROU assets, net $ 218 $ 5 $ 115 $ 19 $ — $ — Finance lease obligations - current $ 17 $ 1 $ 9 $ 1 $ — $ — Finance lease obligations - non-current 214 4 136 18 — — Total finance lease obligations $ 231 $ 5 $ 145 $ 19 $ — $ — As of December 31, 2019 Operating Leases Operating lease ROU assets, net $ 1,800 $ 132 $ 1,428 $ 6 $ 369 $ 93 Operating lease obligations - current $ 229 $ 49 $ 144 $ 2 $ 22 $ 14 Operating lease obligations - non-current 1,615 107 1,282 4 376 78 Total operating lease obligations $ 1,844 $ 156 $ 1,426 $ 6 $ 398 $ 92 Finance Leases Finance lease ROU assets, net $ 216 $ 4 $ 130 $ — $ — $ — Finance lease obligations - current $ 21 $ 1 $ 11 $ — $ — $ — Finance lease obligations - non-current 205 3 145 — — — Total finance lease obligations $ 226 $ 4 $ 156 $ — $ — $ — If not presented separately on the Registrants' balance sheets, amounts related to leases are presented as follows: operating lease ROU assets, net are included in "other deferred charges and assets"; operating lease obligations are included in "other current liabilities" and "other deferred credits and liabilities," as applicable; finance lease ROU assets, net are included in "plant in service"; and finance lease obligations are included in "securities due within one year" and "long-term debt," as applicable. Lease costs for 2020 and 2019, which includes both amounts recognized as operations and maintenance expense and amounts capitalized as part of the cost of another asset, are as follows: Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) 2020 Lease cost Operating lease cost $ 309 $ 55 $ 212 $ 3 $ 29 $ 19 Finance lease cost: Amortization of ROU assets 26 1 15 — — — Interest on lease obligations 11 — 16 — — — Total finance lease cost 37 1 31 — — — Short-term lease costs 39 11 26 — — — Variable lease cost 91 4 76 — 7 — Sublease income — (1) — — — — Total lease cost $ 476 $ 70 $ 345 $ 3 $ 36 $ 19 2019 Lease cost Operating lease cost $ 310 $ 54 $ 206 $ 3 $ 28 $ 18 Finance lease cost: Amortization of ROU assets 28 1 15 — — — Interest on lease obligations 12 — 18 — — — Total finance lease cost 40 1 33 — — — Short-term lease costs 48 19 22 — — — Variable lease cost 105 6 85 — 7 — Sublease income — (1) — — — — Total lease cost $ 503 $ 79 $ 346 $ 3 $ 35 $ 18 Georgia Power has variable lease payments that are based on the amount of energy produced by certain renewable generating facilities subject to PPAs, including $39 million and $42 million in 2020 and 2019, respectively, from finance leases which are included in purchased power on Georgia Power's statements of income, $20 million of which was included in purchased power, affiliates in both 2020 and 2019. Rent expense and PPA capacity expense related to leases for 2018, prior to the adoption of ASC 842, were as follows: Southern Company (a)(b)(c) Alabama Georgia (a) Mississippi (b) Southern Power (c) Southern Company Gas (in millions) 2018: Rent expense $ 192 $ 23 $ 34 $ 4 $ 31 $ 15 PPA capacity expense 231 44 206 — — — (a) Georgia Power's energy-only solar PPAs accounted for as leases contained contingent rent expense of $72 million, of which $29 million related to solar PPAs with Southern Power. (b) Mississippi Power's energy-only solar PPAs accounted for as operating leases contained contingent rent expense of $10 million. (c) Rent expense includes contingent rent expense related to Southern Power's land leases based on wind production and escalation in the Consumer Price Index for All Urban Consumers. Other information with respect to cash and noncash activities related to leases, as well as weighted-average lease terms and discount rates, is as follows: Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) 2020 Other information Cash paid for amounts included in the measurements of lease obligations: Operating cash flows from operating leases $ 310 $ 55 $ 215 $ 3 $ 28 $ 18 Operating cash flows from finance leases 9 — 18 — — — Financing cash flows from finance leases 22 1 11 — — — ROU assets obtained in exchange for new operating lease obligations 227 63 32 — 51 4 ROU assets obtained in exchange for new finance lease obligations 10 2 — — — — 2019 Other information Cash paid for amounts included in the measurements of lease obligations: Operating cash flows from operating leases $ 323 $ 54 $ 210 $ 3 $ 27 $ 18 Operating cash flows from finance leases 10 — 19 — — — Financing cash flows from finance leases 32 1 13 — — — ROU assets obtained in exchange for new operating lease obligations 118 7 21 — 2 19 ROU assets obtained in exchange for new finance lease obligations 35 2 24 — — — Southern Alabama Georgia Mississippi Southern Power Southern Company Gas As of December 31, 2020 Weighted-average remaining lease term in years: Operating leases 14.5 7.8 9.4 6.5 32.1 9.8 Finance leases 18.2 9.7 9.5 14.9 N/A N/A Weighted-average discount rate: Operating leases 4.44 % 4.14 % 4.37 % 3.26 % 5.45 % 3.67 % Finance leases 4.79 % 3.20 % 10.81 % 2.74 % N/A N/A As of December 31, 2019 Weighted-average remaining lease term in years: Operating leases 14.2 3.1 10.2 7.0 32.8 9.9 Finance leases 18.8 12.1 10.5 N/A N/A N/A Weighted-average discount rate: Operating leases 4.53 % 3.33 % 4.46 % 4.02 % 5.66 % 3.7 % Finance leases 5.04 % 3.60 % 10.76 % N/A N/A N/A Maturities of lease liabilities are as follows: As of December 31, 2020 Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Maturity Analysis Operating leases: 2021 $ 300 $ 57 $ 205 $ 2 $ 30 $ 18 2022 287 58 202 4 25 14 2023 230 9 200 1 27 12 2024 187 6 164 1 27 11 2025 165 6 137 — 27 10 Thereafter 1,546 74 701 2 873 35 Total 2,715 210 1,609 10 1,009 100 Less: Present value discount 863 40 302 1 558 18 Operating lease obligations $ 1,852 $ 170 $ 1,307 $ 9 $ 451 $ 82 Finance leases: 2021 $ 28 $ 1 $ 24 $ 2 $ — $ — 2022 25 1 25 1 — — 2023 22 1 25 2 — — 2024 19 1 25 1 — — 2025 16 — 25 2 — — Thereafter 246 1 109 15 — — Total 356 5 233 23 — — Less: Present value discount 125 — 88 4 — — Finance lease obligations $ 231 $ 5 $ 145 $ 19 $ — $ — Payments made under PPAs at Georgia Power for energy generated from certain renewable energy facilities accounted for as operating and finance leases are considered variable lease costs and are therefore not reflected in the above maturity analysis. As of December 31, 2020, Southern Power has additional leases that have not yet commenced, as detailed in the following table: Southern Lease category Land Expected commencement date 2021 Longest lease term expiration 30 years Estimated total obligations (in millions) $12 Lessor The Registrants are each considered lessors in various arrangements that have been determined to contain a lease due to the customer's ability to control the use of the underlying asset owned by the applicable Registrant. For the traditional electric operating companies, these arrangements consist of outdoor lighting contracts accounted for as operating leases with initial terms of up to seven years, after which the contracts renew on a month-to-month basis at the customer's option. For Mississippi Power, these arrangements also include a tolling arrangement related to an electric generating unit accounted for as a sales-type lease with a remaining term of 18 years. For Southern Power, these arrangements consist of PPAs related to electric generating units, including renewable energy facilities, accounted for as operating leases with remaining terms of up to 26 years. Southern Company Gas is the lessor in operating leases related to gas pipelines with remaining terms of up to 22 years. For Southern Company, these arrangements also include PPAs related to fuel cells accounted for as operating leases with remaining terms of up to 14 years. Lease income for 2020 and 2019 is as follows: Southern Alabama Power Georgia Power Mississippi Southern Power Southern Company Gas (in millions) 2020 Lease income - interest income on sales-type leases $ 16 $ — $ — $ 12 $ — $ — Lease income - operating leases 208 45 58 2 87 35 Variable lease income 419 — — — 449 — Total lease income $ 643 $ 45 $ 58 $ 14 $ 536 $ 35 2019 Lease income - interest income on sales-type leases $ 9 $ — $ — $ 9 $ — $ — Lease income - operating leases 273 24 71 — 160 35 Variable lease income 403 — — — 434 — Total lease income $ 685 $ 24 $ 71 $ 9 $ 594 $ 35 Lease payments received under tolling arrangements and PPAs consist of either scheduled payments or variable payments based on the amount of energy produced by the underlying electric generating units. Lease income for Alabama Power and Southern Power is included in wholesale revenues. Scheduled payments to be received under outdoor lighting contracts, tolling arrangements, and PPAs accounted for as leases are presented in the following maturity analyses. No profit or loss was recognized by Mississippi Power upon commencement of a tolling arrangement accounted for as a sales-type lease during the first quarter 2019. Mississippi Power completed construction of additional leased assets under the lease during 2020 and, upon completion, the book value of $26 million was transferred from CWIP to lease receivables, of which $24 million and $2 million is included in other property and investments and other accounts and notes receivable, respectively, at December 31, 2020. The transfer represented a non-cash investing transaction for purposes of the statements of cash flows. Construction of additional leased assets is ongoing and will be transferred to a lease receivable as completed. The undiscounted cash flows to be received by Mississippi Power for in-service leased assets under the lease are as follows: At December 31, 2020 (in millions) 2021 $ 20 2022 19 2023 19 2024 18 2025 17 Thereafter 162 Total undiscounted cash flows $ 255 Lease receivable (*) 138 Difference between undiscounted cash flows and discounted cash flows $ 117 (*) Included in other current assets and other property and investments on the balance sheets. The undiscounted cash flows to be received under operating leases and contracts accounted for as operating leases (adjusted for intercompany eliminations) are as follows: At December 31, 2020 Southern Alabama Georgia Power Southern Southern Company Gas (in millions) 2021 $ 207 $ 83 $ 19 $ 86 $ 35 2022 187 76 8 87 35 2023 138 32 2 88 34 2024 106 4 — 90 33 2025 99 3 — 74 28 Thereafter 978 23 — 313 435 Total $ 1,715 $ 221 $ 29 $ 738 $ 600 Southern Power receives payments for renewable energy under PPAs accounted for as operating leases that are considered contingent rents and are therefore not reflected in the table above. Alabama Power and Southern Power allocate revenue to the nonlease components of PPAs based on the stand-alone selling price of capacity and energy. The undiscounted cash flows to be received under outdoor lighting contracts accounted for as operating leases at Mississippi Power are immaterial. |
LEASES | LEASES On January 1, 2019, the Registrants adopted the provisions of FASB ASC Topic 842 (as amended), Leases (ASC 842), which require lessees to recognize leases with a term of greater than 12 months on the balance sheet as lease obligations, representing the discounted future fixed payments due, along with ROU assets that will be amortized over the term of each lease. The Registrants elected the transition methodology provided by ASC 842, whereby the applicable requirements were applied on a prospective basis as of the adoption date of January 1, 2019, without restating prior periods. The Registrants also elected the package of practical expedients provided by ASC 842 that allows prior determinations of whether existing contracts are, or contain, leases and the classification of existing leases to continue without reassessment. Additionally, the Registrants applied the use-of-hindsight practical expedient in determining lease terms as of the date of adoption and elected the practical expedient that allows existing land easements not previously accounted for as leases not to be reassessed. Lessee As lessee, the Registrants lease certain electric generating units (including renewable energy facilities), real estate/land, communication towers, railcars, and other equipment and vehicles. The major categories of lease obligations are as follows: Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) As of December 31, 2020 Electric generating units $ 941 $ 146 $ 1,368 $ — $ — $ — Real estate/land 815 4 53 2 451 61 Communication towers 158 2 3 — — 20 Railcars 42 16 23 3 — — Other 127 7 5 23 — 1 Total $ 2,083 $ 175 $ 1,452 $ 28 $ 451 $ 82 As of December 31, 2019 Electric generating units $ 990 $ 125 $ 1,487 $ — $ — $ — Real estate/land 782 4 54 2 398 74 Communication towers 154 2 3 — — 18 Railcars 51 21 26 3 — — Other 93 8 12 1 — — Total $ 2,070 $ 160 $ 1,582 $ 6 $ 398 $ 92 Real estate/land leases primarily consist of commercial real estate leases at Southern Company, Georgia Power, and Southern Company Gas and various land leases primarily associated with renewable energy facilities at Southern Power. The commercial real estate leases have remaining terms of up to 24 years while the land leases have remaining terms of up to 46 years, including renewal periods. Communication towers are leased for the installation of equipment to provide cellular phone service to customers and to support the automated meter infrastructure programs at the traditional electric operating companies and Nicor Gas. Communication tower leases have original terms of up to 10 years with options to renew for periods up to 20 years. Renewal options exist in many of the leases. Except as otherwise noted, the expected term used in calculating the lease obligation generally reflects only the noncancelable period of the lease as it is not considered reasonably certain that the lease will be extended. Land leases associated with renewable energy facilities at Southern Power and communication tower leases for automated meter infrastructure at Southern Company Gas include renewal periods reasonably certain of exercise resulting in an expected lease term at least equal to the expected life of the renewable energy facilities and the automated meter infrastructure, respectively. Contracts that Contain a Lease While not specifically structured as a lease, some of the PPAs at Alabama Power and Georgia Power are deemed to represent a lease of the underlying electric generating units when the terms of the PPA convey the right to control the use of the underlying assets. Amounts recorded for leases of electric generating units are generally based on the amount of scheduled capacity payments due over the remaining term of the PPA, which varies between three Short-term Leases Leases with an initial term of 12 months or less are not recorded on the balance sheet; the Registrants generally recognize lease expense for these leases on a straight-line basis over the lease term. Residual Value Guarantees Residual value guarantees exist primarily in railcar leases at Alabama Power and Georgia Power and the amounts probable of being paid under those guarantees are included in the lease payments. All such amounts are immaterial as of December 31, 2020 and 2019. Lease and Nonlease Components For all asset categories, with the exception of electric generating units, gas pipelines, and real estate leases, the Registrants combine lease payments and any nonlease components, such as asset maintenance, for purposes of calculating the lease obligation and the right-of-use asset. Balance sheet amounts recorded for operating and finance leases are as follows: Southern Company Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) As of December 31, 2020 Operating Leases Operating lease ROU assets, net $ 1,802 $ 151 $ 1,308 $ 9 $ 415 $ 81 Operating lease obligations - current $ 241 $ 51 $ 151 $ 2 $ 25 $ 15 Operating lease obligations - non-current 1,611 119 1,156 7 426 67 Total operating lease obligations $ 1,852 $ 170 $ 1,307 $ 9 $ 451 $ 82 Finance Leases Finance lease ROU assets, net $ 218 $ 5 $ 115 $ 19 $ — $ — Finance lease obligations - current $ 17 $ 1 $ 9 $ 1 $ — $ — Finance lease obligations - non-current 214 4 136 18 — — Total finance lease obligations $ 231 $ 5 $ 145 $ 19 $ — $ — As of December 31, 2019 Operating Leases Operating lease ROU assets, net $ 1,800 $ 132 $ 1,428 $ 6 $ 369 $ 93 Operating lease obligations - current $ 229 $ 49 $ 144 $ 2 $ 22 $ 14 Operating lease obligations - non-current 1,615 107 1,282 4 376 78 Total operating lease obligations $ 1,844 $ 156 $ 1,426 $ 6 $ 398 $ 92 Finance Leases Finance lease ROU assets, net $ 216 $ 4 $ 130 $ — $ — $ — Finance lease obligations - current $ 21 $ 1 $ 11 $ — $ — $ — Finance lease obligations - non-current 205 3 145 — — — Total finance lease obligations $ 226 $ 4 $ 156 $ — $ — $ — If not presented separately on the Registrants' balance sheets, amounts related to leases are presented as follows: operating lease ROU assets, net are included in "other deferred charges and assets"; operating lease obligations are included in "other current liabilities" and "other deferred credits and liabilities," as applicable; finance lease ROU assets, net are included in "plant in service"; and finance lease obligations are included in "securities due within one year" and "long-term debt," as applicable. Lease costs for 2020 and 2019, which includes both amounts recognized as operations and maintenance expense and amounts capitalized as part of the cost of another asset, are as follows: Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) 2020 Lease cost Operating lease cost $ 309 $ 55 $ 212 $ 3 $ 29 $ 19 Finance lease cost: Amortization of ROU assets 26 1 15 — — — Interest on lease obligations 11 — 16 — — — Total finance lease cost 37 1 31 — — — Short-term lease costs 39 11 26 — — — Variable lease cost 91 4 76 — 7 — Sublease income — (1) — — — — Total lease cost $ 476 $ 70 $ 345 $ 3 $ 36 $ 19 2019 Lease cost Operating lease cost $ 310 $ 54 $ 206 $ 3 $ 28 $ 18 Finance lease cost: Amortization of ROU assets 28 1 15 — — — Interest on lease obligations 12 — 18 — — — Total finance lease cost 40 1 33 — — — Short-term lease costs 48 19 22 — — — Variable lease cost 105 6 85 — 7 — Sublease income — (1) — — — — Total lease cost $ 503 $ 79 $ 346 $ 3 $ 35 $ 18 Georgia Power has variable lease payments that are based on the amount of energy produced by certain renewable generating facilities subject to PPAs, including $39 million and $42 million in 2020 and 2019, respectively, from finance leases which are included in purchased power on Georgia Power's statements of income, $20 million of which was included in purchased power, affiliates in both 2020 and 2019. Rent expense and PPA capacity expense related to leases for 2018, prior to the adoption of ASC 842, were as follows: Southern Company (a)(b)(c) Alabama Georgia (a) Mississippi (b) Southern Power (c) Southern Company Gas (in millions) 2018: Rent expense $ 192 $ 23 $ 34 $ 4 $ 31 $ 15 PPA capacity expense 231 44 206 — — — (a) Georgia Power's energy-only solar PPAs accounted for as leases contained contingent rent expense of $72 million, of which $29 million related to solar PPAs with Southern Power. (b) Mississippi Power's energy-only solar PPAs accounted for as operating leases contained contingent rent expense of $10 million. (c) Rent expense includes contingent rent expense related to Southern Power's land leases based on wind production and escalation in the Consumer Price Index for All Urban Consumers. Other information with respect to cash and noncash activities related to leases, as well as weighted-average lease terms and discount rates, is as follows: Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) 2020 Other information Cash paid for amounts included in the measurements of lease obligations: Operating cash flows from operating leases $ 310 $ 55 $ 215 $ 3 $ 28 $ 18 Operating cash flows from finance leases 9 — 18 — — — Financing cash flows from finance leases 22 1 11 — — — ROU assets obtained in exchange for new operating lease obligations 227 63 32 — 51 4 ROU assets obtained in exchange for new finance lease obligations 10 2 — — — — 2019 Other information Cash paid for amounts included in the measurements of lease obligations: Operating cash flows from operating leases $ 323 $ 54 $ 210 $ 3 $ 27 $ 18 Operating cash flows from finance leases 10 — 19 — — — Financing cash flows from finance leases 32 1 13 — — — ROU assets obtained in exchange for new operating lease obligations 118 7 21 — 2 19 ROU assets obtained in exchange for new finance lease obligations 35 2 24 — — — Southern Alabama Georgia Mississippi Southern Power Southern Company Gas As of December 31, 2020 Weighted-average remaining lease term in years: Operating leases 14.5 7.8 9.4 6.5 32.1 9.8 Finance leases 18.2 9.7 9.5 14.9 N/A N/A Weighted-average discount rate: Operating leases 4.44 % 4.14 % 4.37 % 3.26 % 5.45 % 3.67 % Finance leases 4.79 % 3.20 % 10.81 % 2.74 % N/A N/A As of December 31, 2019 Weighted-average remaining lease term in years: Operating leases 14.2 3.1 10.2 7.0 32.8 9.9 Finance leases 18.8 12.1 10.5 N/A N/A N/A Weighted-average discount rate: Operating leases 4.53 % 3.33 % 4.46 % 4.02 % 5.66 % 3.7 % Finance leases 5.04 % 3.60 % 10.76 % N/A N/A N/A Maturities of lease liabilities are as follows: As of December 31, 2020 Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Maturity Analysis Operating leases: 2021 $ 300 $ 57 $ 205 $ 2 $ 30 $ 18 2022 287 58 202 4 25 14 2023 230 9 200 1 27 12 2024 187 6 164 1 27 11 2025 165 6 137 — 27 10 Thereafter 1,546 74 701 2 873 35 Total 2,715 210 1,609 10 1,009 100 Less: Present value discount 863 40 302 1 558 18 Operating lease obligations $ 1,852 $ 170 $ 1,307 $ 9 $ 451 $ 82 Finance leases: 2021 $ 28 $ 1 $ 24 $ 2 $ — $ — 2022 25 1 25 1 — — 2023 22 1 25 2 — — 2024 19 1 25 1 — — 2025 16 — 25 2 — — Thereafter 246 1 109 15 — — Total 356 5 233 23 — — Less: Present value discount 125 — 88 4 — — Finance lease obligations $ 231 $ 5 $ 145 $ 19 $ — $ — Payments made under PPAs at Georgia Power for energy generated from certain renewable energy facilities accounted for as operating and finance leases are considered variable lease costs and are therefore not reflected in the above maturity analysis. As of December 31, 2020, Southern Power has additional leases that have not yet commenced, as detailed in the following table: Southern Lease category Land Expected commencement date 2021 Longest lease term expiration 30 years Estimated total obligations (in millions) $12 Lessor The Registrants are each considered lessors in various arrangements that have been determined to contain a lease due to the customer's ability to control the use of the underlying asset owned by the applicable Registrant. For the traditional electric operating companies, these arrangements consist of outdoor lighting contracts accounted for as operating leases with initial terms of up to seven years, after which the contracts renew on a month-to-month basis at the customer's option. For Mississippi Power, these arrangements also include a tolling arrangement related to an electric generating unit accounted for as a sales-type lease with a remaining term of 18 years. For Southern Power, these arrangements consist of PPAs related to electric generating units, including renewable energy facilities, accounted for as operating leases with remaining terms of up to 26 years. Southern Company Gas is the lessor in operating leases related to gas pipelines with remaining terms of up to 22 years. For Southern Company, these arrangements also include PPAs related to fuel cells accounted for as operating leases with remaining terms of up to 14 years. Lease income for 2020 and 2019 is as follows: Southern Alabama Power Georgia Power Mississippi Southern Power Southern Company Gas (in millions) 2020 Lease income - interest income on sales-type leases $ 16 $ — $ — $ 12 $ — $ — Lease income - operating leases 208 45 58 2 87 35 Variable lease income 419 — — — 449 — Total lease income $ 643 $ 45 $ 58 $ 14 $ 536 $ 35 2019 Lease income - interest income on sales-type leases $ 9 $ — $ — $ 9 $ — $ — Lease income - operating leases 273 24 71 — 160 35 Variable lease income 403 — — — 434 — Total lease income $ 685 $ 24 $ 71 $ 9 $ 594 $ 35 Lease payments received under tolling arrangements and PPAs consist of either scheduled payments or variable payments based on the amount of energy produced by the underlying electric generating units. Lease income for Alabama Power and Southern Power is included in wholesale revenues. Scheduled payments to be received under outdoor lighting contracts, tolling arrangements, and PPAs accounted for as leases are presented in the following maturity analyses. No profit or loss was recognized by Mississippi Power upon commencement of a tolling arrangement accounted for as a sales-type lease during the first quarter 2019. Mississippi Power completed construction of additional leased assets under the lease during 2020 and, upon completion, the book value of $26 million was transferred from CWIP to lease receivables, of which $24 million and $2 million is included in other property and investments and other accounts and notes receivable, respectively, at December 31, 2020. The transfer represented a non-cash investing transaction for purposes of the statements of cash flows. Construction of additional leased assets is ongoing and will be transferred to a lease receivable as completed. The undiscounted cash flows to be received by Mississippi Power for in-service leased assets under the lease are as follows: At December 31, 2020 (in millions) 2021 $ 20 2022 19 2023 19 2024 18 2025 17 Thereafter 162 Total undiscounted cash flows $ 255 Lease receivable (*) 138 Difference between undiscounted cash flows and discounted cash flows $ 117 (*) Included in other current assets and other property and investments on the balance sheets. The undiscounted cash flows to be received under operating leases and contracts accounted for as operating leases (adjusted for intercompany eliminations) are as follows: At December 31, 2020 Southern Alabama Georgia Power Southern Southern Company Gas (in millions) 2021 $ 207 $ 83 $ 19 $ 86 $ 35 2022 187 76 8 87 35 2023 138 32 2 88 34 2024 106 4 — 90 33 2025 99 3 — 74 28 Thereafter 978 23 — 313 435 Total $ 1,715 $ 221 $ 29 $ 738 $ 600 Southern Power receives payments for renewable energy under PPAs accounted for as operating leases that are considered contingent rents and are therefore not reflected in the table above. Alabama Power and Southern Power allocate revenue to the nonlease components of PPAs based on the stand-alone selling price of capacity and energy. The undiscounted cash flows to be received under outdoor lighting contracts accounted for as operating leases at Mississippi Power are immaterial. |
LEASES | LEASES On January 1, 2019, the Registrants adopted the provisions of FASB ASC Topic 842 (as amended), Leases (ASC 842), which require lessees to recognize leases with a term of greater than 12 months on the balance sheet as lease obligations, representing the discounted future fixed payments due, along with ROU assets that will be amortized over the term of each lease. The Registrants elected the transition methodology provided by ASC 842, whereby the applicable requirements were applied on a prospective basis as of the adoption date of January 1, 2019, without restating prior periods. The Registrants also elected the package of practical expedients provided by ASC 842 that allows prior determinations of whether existing contracts are, or contain, leases and the classification of existing leases to continue without reassessment. Additionally, the Registrants applied the use-of-hindsight practical expedient in determining lease terms as of the date of adoption and elected the practical expedient that allows existing land easements not previously accounted for as leases not to be reassessed. Lessee As lessee, the Registrants lease certain electric generating units (including renewable energy facilities), real estate/land, communication towers, railcars, and other equipment and vehicles. The major categories of lease obligations are as follows: Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) As of December 31, 2020 Electric generating units $ 941 $ 146 $ 1,368 $ — $ — $ — Real estate/land 815 4 53 2 451 61 Communication towers 158 2 3 — — 20 Railcars 42 16 23 3 — — Other 127 7 5 23 — 1 Total $ 2,083 $ 175 $ 1,452 $ 28 $ 451 $ 82 As of December 31, 2019 Electric generating units $ 990 $ 125 $ 1,487 $ — $ — $ — Real estate/land 782 4 54 2 398 74 Communication towers 154 2 3 — — 18 Railcars 51 21 26 3 — — Other 93 8 12 1 — — Total $ 2,070 $ 160 $ 1,582 $ 6 $ 398 $ 92 Real estate/land leases primarily consist of commercial real estate leases at Southern Company, Georgia Power, and Southern Company Gas and various land leases primarily associated with renewable energy facilities at Southern Power. The commercial real estate leases have remaining terms of up to 24 years while the land leases have remaining terms of up to 46 years, including renewal periods. Communication towers are leased for the installation of equipment to provide cellular phone service to customers and to support the automated meter infrastructure programs at the traditional electric operating companies and Nicor Gas. Communication tower leases have original terms of up to 10 years with options to renew for periods up to 20 years. Renewal options exist in many of the leases. Except as otherwise noted, the expected term used in calculating the lease obligation generally reflects only the noncancelable period of the lease as it is not considered reasonably certain that the lease will be extended. Land leases associated with renewable energy facilities at Southern Power and communication tower leases for automated meter infrastructure at Southern Company Gas include renewal periods reasonably certain of exercise resulting in an expected lease term at least equal to the expected life of the renewable energy facilities and the automated meter infrastructure, respectively. Contracts that Contain a Lease While not specifically structured as a lease, some of the PPAs at Alabama Power and Georgia Power are deemed to represent a lease of the underlying electric generating units when the terms of the PPA convey the right to control the use of the underlying assets. Amounts recorded for leases of electric generating units are generally based on the amount of scheduled capacity payments due over the remaining term of the PPA, which varies between three Short-term Leases Leases with an initial term of 12 months or less are not recorded on the balance sheet; the Registrants generally recognize lease expense for these leases on a straight-line basis over the lease term. Residual Value Guarantees Residual value guarantees exist primarily in railcar leases at Alabama Power and Georgia Power and the amounts probable of being paid under those guarantees are included in the lease payments. All such amounts are immaterial as of December 31, 2020 and 2019. Lease and Nonlease Components For all asset categories, with the exception of electric generating units, gas pipelines, and real estate leases, the Registrants combine lease payments and any nonlease components, such as asset maintenance, for purposes of calculating the lease obligation and the right-of-use asset. Balance sheet amounts recorded for operating and finance leases are as follows: Southern Company Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) As of December 31, 2020 Operating Leases Operating lease ROU assets, net $ 1,802 $ 151 $ 1,308 $ 9 $ 415 $ 81 Operating lease obligations - current $ 241 $ 51 $ 151 $ 2 $ 25 $ 15 Operating lease obligations - non-current 1,611 119 1,156 7 426 67 Total operating lease obligations $ 1,852 $ 170 $ 1,307 $ 9 $ 451 $ 82 Finance Leases Finance lease ROU assets, net $ 218 $ 5 $ 115 $ 19 $ — $ — Finance lease obligations - current $ 17 $ 1 $ 9 $ 1 $ — $ — Finance lease obligations - non-current 214 4 136 18 — — Total finance lease obligations $ 231 $ 5 $ 145 $ 19 $ — $ — As of December 31, 2019 Operating Leases Operating lease ROU assets, net $ 1,800 $ 132 $ 1,428 $ 6 $ 369 $ 93 Operating lease obligations - current $ 229 $ 49 $ 144 $ 2 $ 22 $ 14 Operating lease obligations - non-current 1,615 107 1,282 4 376 78 Total operating lease obligations $ 1,844 $ 156 $ 1,426 $ 6 $ 398 $ 92 Finance Leases Finance lease ROU assets, net $ 216 $ 4 $ 130 $ — $ — $ — Finance lease obligations - current $ 21 $ 1 $ 11 $ — $ — $ — Finance lease obligations - non-current 205 3 145 — — — Total finance lease obligations $ 226 $ 4 $ 156 $ — $ — $ — If not presented separately on the Registrants' balance sheets, amounts related to leases are presented as follows: operating lease ROU assets, net are included in "other deferred charges and assets"; operating lease obligations are included in "other current liabilities" and "other deferred credits and liabilities," as applicable; finance lease ROU assets, net are included in "plant in service"; and finance lease obligations are included in "securities due within one year" and "long-term debt," as applicable. Lease costs for 2020 and 2019, which includes both amounts recognized as operations and maintenance expense and amounts capitalized as part of the cost of another asset, are as follows: Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) 2020 Lease cost Operating lease cost $ 309 $ 55 $ 212 $ 3 $ 29 $ 19 Finance lease cost: Amortization of ROU assets 26 1 15 — — — Interest on lease obligations 11 — 16 — — — Total finance lease cost 37 1 31 — — — Short-term lease costs 39 11 26 — — — Variable lease cost 91 4 76 — 7 — Sublease income — (1) — — — — Total lease cost $ 476 $ 70 $ 345 $ 3 $ 36 $ 19 2019 Lease cost Operating lease cost $ 310 $ 54 $ 206 $ 3 $ 28 $ 18 Finance lease cost: Amortization of ROU assets 28 1 15 — — — Interest on lease obligations 12 — 18 — — — Total finance lease cost 40 1 33 — — — Short-term lease costs 48 19 22 — — — Variable lease cost 105 6 85 — 7 — Sublease income — (1) — — — — Total lease cost $ 503 $ 79 $ 346 $ 3 $ 35 $ 18 Georgia Power has variable lease payments that are based on the amount of energy produced by certain renewable generating facilities subject to PPAs, including $39 million and $42 million in 2020 and 2019, respectively, from finance leases which are included in purchased power on Georgia Power's statements of income, $20 million of which was included in purchased power, affiliates in both 2020 and 2019. Rent expense and PPA capacity expense related to leases for 2018, prior to the adoption of ASC 842, were as follows: Southern Company (a)(b)(c) Alabama Georgia (a) Mississippi (b) Southern Power (c) Southern Company Gas (in millions) 2018: Rent expense $ 192 $ 23 $ 34 $ 4 $ 31 $ 15 PPA capacity expense 231 44 206 — — — (a) Georgia Power's energy-only solar PPAs accounted for as leases contained contingent rent expense of $72 million, of which $29 million related to solar PPAs with Southern Power. (b) Mississippi Power's energy-only solar PPAs accounted for as operating leases contained contingent rent expense of $10 million. (c) Rent expense includes contingent rent expense related to Southern Power's land leases based on wind production and escalation in the Consumer Price Index for All Urban Consumers. Other information with respect to cash and noncash activities related to leases, as well as weighted-average lease terms and discount rates, is as follows: Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) 2020 Other information Cash paid for amounts included in the measurements of lease obligations: Operating cash flows from operating leases $ 310 $ 55 $ 215 $ 3 $ 28 $ 18 Operating cash flows from finance leases 9 — 18 — — — Financing cash flows from finance leases 22 1 11 — — — ROU assets obtained in exchange for new operating lease obligations 227 63 32 — 51 4 ROU assets obtained in exchange for new finance lease obligations 10 2 — — — — 2019 Other information Cash paid for amounts included in the measurements of lease obligations: Operating cash flows from operating leases $ 323 $ 54 $ 210 $ 3 $ 27 $ 18 Operating cash flows from finance leases 10 — 19 — — — Financing cash flows from finance leases 32 1 13 — — — ROU assets obtained in exchange for new operating lease obligations 118 7 21 — 2 19 ROU assets obtained in exchange for new finance lease obligations 35 2 24 — — — Southern Alabama Georgia Mississippi Southern Power Southern Company Gas As of December 31, 2020 Weighted-average remaining lease term in years: Operating leases 14.5 7.8 9.4 6.5 32.1 9.8 Finance leases 18.2 9.7 9.5 14.9 N/A N/A Weighted-average discount rate: Operating leases 4.44 % 4.14 % 4.37 % 3.26 % 5.45 % 3.67 % Finance leases 4.79 % 3.20 % 10.81 % 2.74 % N/A N/A As of December 31, 2019 Weighted-average remaining lease term in years: Operating leases 14.2 3.1 10.2 7.0 32.8 9.9 Finance leases 18.8 12.1 10.5 N/A N/A N/A Weighted-average discount rate: Operating leases 4.53 % 3.33 % 4.46 % 4.02 % 5.66 % 3.7 % Finance leases 5.04 % 3.60 % 10.76 % N/A N/A N/A Maturities of lease liabilities are as follows: As of December 31, 2020 Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Maturity Analysis Operating leases: 2021 $ 300 $ 57 $ 205 $ 2 $ 30 $ 18 2022 287 58 202 4 25 14 2023 230 9 200 1 27 12 2024 187 6 164 1 27 11 2025 165 6 137 — 27 10 Thereafter 1,546 74 701 2 873 35 Total 2,715 210 1,609 10 1,009 100 Less: Present value discount 863 40 302 1 558 18 Operating lease obligations $ 1,852 $ 170 $ 1,307 $ 9 $ 451 $ 82 Finance leases: 2021 $ 28 $ 1 $ 24 $ 2 $ — $ — 2022 25 1 25 1 — — 2023 22 1 25 2 — — 2024 19 1 25 1 — — 2025 16 — 25 2 — — Thereafter 246 1 109 15 — — Total 356 5 233 23 — — Less: Present value discount 125 — 88 4 — — Finance lease obligations $ 231 $ 5 $ 145 $ 19 $ — $ — Payments made under PPAs at Georgia Power for energy generated from certain renewable energy facilities accounted for as operating and finance leases are considered variable lease costs and are therefore not reflected in the above maturity analysis. As of December 31, 2020, Southern Power has additional leases that have not yet commenced, as detailed in the following table: Southern Lease category Land Expected commencement date 2021 Longest lease term expiration 30 years Estimated total obligations (in millions) $12 Lessor The Registrants are each considered lessors in various arrangements that have been determined to contain a lease due to the customer's ability to control the use of the underlying asset owned by the applicable Registrant. For the traditional electric operating companies, these arrangements consist of outdoor lighting contracts accounted for as operating leases with initial terms of up to seven years, after which the contracts renew on a month-to-month basis at the customer's option. For Mississippi Power, these arrangements also include a tolling arrangement related to an electric generating unit accounted for as a sales-type lease with a remaining term of 18 years. For Southern Power, these arrangements consist of PPAs related to electric generating units, including renewable energy facilities, accounted for as operating leases with remaining terms of up to 26 years. Southern Company Gas is the lessor in operating leases related to gas pipelines with remaining terms of up to 22 years. For Southern Company, these arrangements also include PPAs related to fuel cells accounted for as operating leases with remaining terms of up to 14 years. Lease income for 2020 and 2019 is as follows: Southern Alabama Power Georgia Power Mississippi Southern Power Southern Company Gas (in millions) 2020 Lease income - interest income on sales-type leases $ 16 $ — $ — $ 12 $ — $ — Lease income - operating leases 208 45 58 2 87 35 Variable lease income 419 — — — 449 — Total lease income $ 643 $ 45 $ 58 $ 14 $ 536 $ 35 2019 Lease income - interest income on sales-type leases $ 9 $ — $ — $ 9 $ — $ — Lease income - operating leases 273 24 71 — 160 35 Variable lease income 403 — — — 434 — Total lease income $ 685 $ 24 $ 71 $ 9 $ 594 $ 35 Lease payments received under tolling arrangements and PPAs consist of either scheduled payments or variable payments based on the amount of energy produced by the underlying electric generating units. Lease income for Alabama Power and Southern Power is included in wholesale revenues. Scheduled payments to be received under outdoor lighting contracts, tolling arrangements, and PPAs accounted for as leases are presented in the following maturity analyses. No profit or loss was recognized by Mississippi Power upon commencement of a tolling arrangement accounted for as a sales-type lease during the first quarter 2019. Mississippi Power completed construction of additional leased assets under the lease during 2020 and, upon completion, the book value of $26 million was transferred from CWIP to lease receivables, of which $24 million and $2 million is included in other property and investments and other accounts and notes receivable, respectively, at December 31, 2020. The transfer represented a non-cash investing transaction for purposes of the statements of cash flows. Construction of additional leased assets is ongoing and will be transferred to a lease receivable as completed. The undiscounted cash flows to be received by Mississippi Power for in-service leased assets under the lease are as follows: At December 31, 2020 (in millions) 2021 $ 20 2022 19 2023 19 2024 18 2025 17 Thereafter 162 Total undiscounted cash flows $ 255 Lease receivable (*) 138 Difference between undiscounted cash flows and discounted cash flows $ 117 (*) Included in other current assets and other property and investments on the balance sheets. The undiscounted cash flows to be received under operating leases and contracts accounted for as operating leases (adjusted for intercompany eliminations) are as follows: At December 31, 2020 Southern Alabama Georgia Power Southern Southern Company Gas (in millions) 2021 $ 207 $ 83 $ 19 $ 86 $ 35 2022 187 76 8 87 35 2023 138 32 2 88 34 2024 106 4 — 90 33 2025 99 3 — 74 28 Thereafter 978 23 — 313 435 Total $ 1,715 $ 221 $ 29 $ 738 $ 600 Southern Power receives payments for renewable energy under PPAs accounted for as operating leases that are considered contingent rents and are therefore not reflected in the table above. Alabama Power and Southern Power allocate revenue to the nonlease components of PPAs based on the stand-alone selling price of capacity and energy. The undiscounted cash flows to be received under outdoor lighting contracts accounted for as operating leases at Mississippi Power are immaterial. |
INCOME TAXES
INCOME TAXES | 12 Months Ended |
Dec. 31, 2020 | |
Income Tax Disclosure [Abstract] | |
INCOME TAXES | INCOME TAXES Southern Company files a consolidated federal income tax return and the Registrants file various state income tax returns, some of which are combined or unitary. Under a joint consolidated income tax allocation agreement, each Southern Company subsidiary's current and deferred tax expense is computed on a stand-alone basis and each subsidiary is allocated an amount of tax similar to that which would be paid if it filed a separate income tax return. In accordance with IRS regulations, each company is jointly and severally liable for the federal tax liability. Federal Tax Reform Legislation Following the enactment of the Tax Reform Legislation, the SEC staff issued Staff Accounting Bulletin 118 – "Income Tax Accounting Implications of the Tax Cuts and Jobs Act" (SAB 118), which provided for a measurement period of up to one year from the enactment date to complete accounting under GAAP for the tax effects of the legislation. Following the 2017 tax return filing in the fourth quarter 2018, each of the Registrants considered the measurement of impacts from the Tax Reform Legislation on deferred income tax assets and liabilities, primarily due to the impact of the reduction of the corporate income tax rate, to be complete as of December 31, 2018. Current and Deferred Income Taxes Details of income tax provisions are as follows: 2020 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Federal — Current $ 199 $ 198 $ 365 $ 18 $ (303) $ 82 Deferred 70 44 (224) (14) 299 53 269 242 141 4 (4) 135 State — Current 100 61 60 — (4) 35 Deferred 24 34 (49) 10 11 3 124 95 11 10 7 38 Total $ 393 $ 337 $ 152 $ 14 $ 3 $ 173 2019 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Federal — Current $ 156 $ 61 $ 264 $ (6) $ (717) $ (120) Deferred 1,237 125 180 26 647 195 1,393 186 444 20 (70) 75 State — Current 275 12 6 (1) 1 37 Deferred 130 72 22 11 13 18 405 84 28 10 14 55 Total $ 1,798 $ 270 $ 472 $ 30 $ (56) $ 130 2018 Southern Company Alabama Power Georgia Mississippi Southern Power Southern Company Gas (in millions) Federal — Current $ 167 $ 91 $ 393 $ (567) $ 85 $ 334 Deferred 231 123 (249) 575 (154) 33 398 214 144 8 (69) 367 State — Current 188 26 81 (10) (9) 131 Deferred (137) 51 (11) (100) (86) (34) 51 77 70 (110) (95) 97 Total $ 449 $ 291 $ 214 $ (102) $ (164) $ 464 Southern Company's and Southern Power's ITCs and PTCs generated in the current tax year and carried forward from prior tax years that cannot be utilized in the current tax year are reclassified from current to deferred taxes in federal income tax expense in the tables above. Southern Power's ITCs and PTCs reclassified in this manner include $5 million for 2020, $51 million for 2019, and $128 million for 2018. Southern Power received $340 million, $734 million, and $5 million of cash related to federal ITCs under renewable energy initiatives in 2020, 2019, and 2018, respectively. See "Deferred Tax Assets and Liabilities" and "Tax Credit Carryforwards" herein for additional information. In accordance with regulatory requirements, deferred federal ITCs for the traditional electric operating companies are deferred and amortized over the average life of the related property, with such amortization normally applied as a credit to reduce depreciation and amortization in the statements of income. Southern Power's and the natural gas distribution utilities' deferred federal ITCs, as well as certain state ITCs for Nicor Gas, are deferred and amortized to income tax expense over the life of the respective asset. ITCs amortized in 2020, 2019, and 2018 were immaterial for the traditional electric operating companies and Southern Company Gas and were as follows for Southern Company and Southern Power: Southern Company Southern Power (in millions) 2020 $ 84 $ 59 2019 181 151 2018 87 58 When Southern Power recognizes tax credits, the tax basis of the asset is reduced by 50% of the ITCs received, resulting in a net deferred tax asset. Southern Power has elected to recognize the tax benefit of this basis difference as a reduction to income tax expense in the year in which the plant reaches commercial operation. The tax benefit of the related basis differences reduced income tax expense by $5 million and $1 million in 2019 and 2018, respectively. State ITCs and other state credits, which are recognized in the period in which the credits are generated, reduced Georgia Power's income tax expense by $67 million in 2020, $51 million in 2019, and $21 million in 2018. Southern Power's federal and state PTCs, which are recognized in the period in which the credits are generated, reduced Southern Power's income tax expense by $15 million in 2020, $12 million in 2019, and $141 million in 2018. Legal Entity Reorganizations In 2018, Southern Power completed the final stage of a legal entity reorganization of various direct and indirect subsidiaries that own and operate substantially all of its solar facilities, including certain subsidiaries owned in partnership with various third parties, and also completed a legal entity reorganization of eight operating wind facilities under a new holding company, SP Wind. The reorganizations resulted in net state tax benefits related to certain changes in apportionment rates totaling approximately $65 million, which were recorded in 2018. Effective Tax Rate Southern Company's effective tax rate is typically lower than the statutory rate due to employee stock plans' dividend deduction, non-taxable AFUDC equity at the traditional electric operating companies, flowback of excess deferred income taxes at the regulated utilities, and federal income tax benefits from ITCs and PTCs primarily at Southern Power. A reconciliation of the federal statutory income tax rate to the effective income tax rate is as follows: 2020 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas Federal statutory rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % State income tax, net of federal deduction 2.8 5.0 0.5 4.8 2.7 4.0 Employee stock plans' dividend deduction (0.7) — — — — — Non-deductible book depreciation 0.7 0.6 0.8 0.5 — — Flowback of excess deferred income taxes (8.8) (3.1) (12.0) (18.5) — (2.7) AFUDC-Equity (0.8) (0.6) (1.1) (0.1) — — Federal PTCs — — — — (2.5) — Amortization of ITC (1.6) (0.1) (0.1) (0.1) (22.1) (0.1) Noncontrolling interests — — — — 3.1 — Leveraged lease impairments (1.6) — — — — — Other 0.2 (0.3) (0.3) 0.9 (0.9) 0.5 Effective income tax (benefit) rate 11.2 % 22.5 % 8.8 % 8.5 % 1.3 % 22.7 % 2019 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas Federal statutory rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % State income tax, net of federal deduction 4.9 4.9 1.0 4.3 4.0 6.1 Employee stock plans' dividend deduction (0.4) — — — — — Non-deductible book depreciation 0.3 0.6 0.5 0.4 — — Flowback of excess deferred income taxes (2.1) (5.3) — (12.6) — (6.0) AFUDC-Equity (0.4) (0.8) (0.6) (0.1) — — ITC basis difference (0.1) — — — (1.9) — Amortization of ITC (0.8) (0.1) (0.1) (0.1) (16.1) (0.1) Tax impact from sale of subsidiaries 5.1 — — — (27.6) (1.4) Noncontrolling interests — — — — 0.8 — Other — (0.4) (0.3) 4.9 (0.6) (1.4) Effective income tax (benefit) rate 27.5 % 19.9 % 21.5 % 17.8 % (20.4) % 18.2 % 2018 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas Federal statutory rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % State income tax, net of federal deduction 1.8 5.0 5.5 (65.1) (90.8) 9.2 Employee stock plans' dividend deduction (1.0) — — — — — Non-deductible book depreciation 0.8 0.6 1.2 0.7 — — Flowback of excess deferred income taxes (4.0) (1.8) — (4.1) — (3.0) AFUDC-Equity (1.0) (1.0) (1.4) — — — ITC basis difference (0.6) — — — (0.2) — Federal PTCs (4.7) — — — (156.6) — Amortization of ITC (2.0) (0.1) (0.2) (0.2) (55.4) (0.1) Tax impact from sale of subsidiaries 8.6 — — — — 28.5 Tax Reform Legislation (1.4) — (4.9) (26.3) 96.1 (0.4) Noncontrolling interests (0.4) — — — (14.9) — Other (0.8) (0.1) 0.1 (1.4) 2.0 0.3 Effective income tax (benefit) rate 16.3 % 23.6 % 21.3 % (75.4) % (198.8) % 55.5 % Deferred Tax Assets and Liabilities The tax effects of temporary differences between the carrying amounts of assets and liabilities in the financial statements of the Registrants and their respective tax bases, which give rise to deferred tax assets and liabilities, are as follows: December 31, 2020 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Deferred tax liabilities — Accelerated depreciation $ 8,950 $ 2,453 $ 3,228 $ 319 $ 1,389 $ 1,349 Property basis differences 1,999 1,010 689 148 — 135 Federal effect of net state deferred tax assets — — — 25 — — Leveraged lease basis differences 142 — — — — — Employee benefit obligations 739 250 362 39 12 26 Premium on reacquired debt 78 12 66 — — — Regulatory assets – Storm damage reserves 80 — 80 — — — Employee benefit obligations 1,313 348 438 62 — 45 Remaining book value of retired assets 270 123 141 6 — — AROs 1,969 764 1,165 40 — — AROs 804 328 429 — — — Other 437 128 82 66 12 138 Total deferred income tax liabilities 16,781 5,416 6,680 705 1,413 1,693 Deferred tax assets — Federal effect of net state deferred tax liabilities 284 151 59 — 26 70 State effect of federal deferred taxes 126 126 — — — — Employee benefit obligations 1,511 369 522 80 6 100 Other property basis differences 223 — 72 — 134 — ITC and PTC carryforward 1,853 12 539 — 1,110 — Long-term debt fair value adjustment 86 — — — — 86 Other partnership basis difference 166 — — — 166 — Other comprehensive losses 128 7 17 — 25 — AROs 2,773 1,092 1,594 40 — — Estimated loss on plants under construction 369 — 369 — — — Other deferred state tax attributes 357 — 9 250 68 10 Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) 338 243 76 19 — — Other 660 143 186 39 52 166 Total deferred income tax assets 8,874 2,143 3,443 428 1,587 432 Valuation allowance (136) — (35) (41) (35) (4) Net deferred income tax assets 8,738 2,143 3,408 387 1,552 428 Net deferred income taxes (assets)/liabilities $ 8,043 $ 3,273 $ 3,272 $ 318 $ (139) $ 1,265 Recognized in the balance sheets: Accumulated deferred income taxes – assets $ (132) $ — $ — $ (129) $ (262) $ — Accumulated deferred income taxes – liabilities $ 8,175 $ 3,273 $ 3,272 $ 447 $ 123 $ 1,265 December 31, 2019 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Deferred tax liabilities — Accelerated depreciation $ 8,711 $ 2,402 $ 3,058 $ 315 $ 1,422 $ 1,288 Property basis differences 1,843 912 643 143 — 133 Federal effect of net state deferred tax assets — — — 24 — — Leveraged lease basis differences 236 — — — — — Employee benefit obligations 704 242 351 38 12 12 Premium on reacquired debt 83 13 70 — — — Regulatory assets – Storm damage reserves 109 — 109 — — — Employee benefit obligations 1,174 311 403 55 — 45 Remaining book value of retired assets 341 174 159 8 — — AROs 1,723 613 1,066 44 — — AROs 814 360 405 — — — Other 523 134 81 68 11 198 Total deferred income tax liabilities 16,261 5,161 6,345 695 1,445 1,676 Deferred tax assets — Federal effect of net state deferred tax liabilities 277 162 63 — 24 56 Employee benefit obligations 1,385 334 488 72 5 111 Other property basis differences 230 — 65 — 146 — ITC and PTC carryforward 2,098 11 435 — 1,445 — Long-term debt fair value adjustment 97 — — — — 97 Other partnership basis difference 169 — — — 169 — Other comprehensive losses 112 8 18 — 10 — AROs 2,537 973 1,471 44 — — Estimated loss on plants under construction 283 — 283 — — — Other deferred state tax attributes 402 — 13 251 72 8 Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) 401 240 133 28 — — Other 689 173 154 56 46 190 Total deferred income tax assets 8,680 1,901 3,123 451 1,917 462 Valuation allowance (137) — (35) (41) (36) (5) Net deferred income tax assets 8,543 1,901 3,088 410 1,881 457 Net deferred income taxes (assets)/liabilities $ 7,718 $ 3,260 $ 3,257 $ 285 $ (436) $ 1,219 Recognized in the balance sheets: Accumulated deferred income taxes – assets $ (170) $ — $ — $ (139) $ (551) $ — Accumulated deferred income taxes – liabilities $ 7,888 $ 3,260 $ 3,257 $ 424 $ 115 $ 1,219 The traditional electric operating companies and the natural gas distribution utilities have tax-related regulatory assets (deferred income tax charges) and regulatory liabilities (deferred income tax credits). The regulatory assets are primarily attributable to tax benefits flowed through to customers in prior years, deferred taxes previously recognized at rates lower than the current enacted tax law, and taxes applicable to capitalized interest. The regulatory liabilities are primarily attributable to deferred taxes previously recognized at rates higher than the current enacted tax law and to unamortized ITCs. See Note 2 for each Registrant's related balances at December 31, 2020 and 2019. Tax Credit Carryforwards Federal ITC/PTC carryforwards at December 31, 2020 were as follows: Southern Company Alabama Georgia Southern (in millions) Federal ITC/PTC carryforwards $ 1,428 $ 12 $ 114 $ 1,110 Tax Year in which federal ITC/PTC carryforwards begin expiring 2031 2032 2031 2035 Year by which federal ITC/PTC carryforwards are expected to be utilized 2024 2023 2023 2024 The estimated tax credit utilization reflects the various sale transactions described in Note 15 and could be further delayed by numerous factors, including the acquisition of additional renewable projects, the purchase of rights to additional PTCs of Plant Vogtle Units 3 and 4 pursuant to certain joint ownership agreements, potential impacts of the COVID-19 pandemic, and changes in taxable income projections. See Note 2 under "Georgia Power – Nuclear Construction" for additional information on Plant Vogtle Units 3 and 4. At December 31, 2020, Georgia Power also had approximately $343 million in net state investment and other net state tax credit carryforwards for the State of Georgia that will expire between tax years 2021 and 2030 and are not expected to be fully utilized. Georgia Power has a net state valuation allowance of $28 million associated with these carryforwards. The ultimate outcome of these matters cannot be determined at this time. Net Operating Loss Carryforwards At December 31, 2020, the net state income tax benefit of state and local NOL carryforwards for Southern Company's subsidiaries were as follows: Company/Jurisdiction Approximate Net State Income Tax Benefit of NOL Carryforwards Tax Year NOL Mississippi Power Mississippi $ 200 2031 Southern Power Oklahoma 39 2035 Florida 11 2034 South Carolina 2 2036 Other states 1 Various Southern Power Total $ 53 Other (*) New York 11 2035 New York City 14 2035 Other states 21 Various Southern Company Total $ 299 (*) Represents other Southern Company subsidiaries. Alabama Power, Georgia Power, and Southern Company Gas did not have material state or local NOL carryforwards at December 31, 2020. State NOLs for Mississippi, Oklahoma, and Florida are not expected to be fully utilized prior to expiration. At December 31, 2020, Mississippi Power had a net state valuation allowance of $32 million for the Mississippi NOL and Southern Power had net state valuation allowances of $16 million for the Oklahoma NOL and $11 million for the Florida NOL. The ultimate outcome of these matters cannot be determined at this time. Unrecognized Tax Benefits Changes in unrecognized tax benefits for the periods presented were as follows: Southern Company (in millions) Unrecognized tax benefits at December 31, 2017 $ 18 Tax position changes – decrease from prior periods (18) Unrecognized tax benefits at December 31, 2018 and 2019 $ — Tax positions changes – increase from prior periods 44 Unrecognized tax benefits at December 31, 2020 $ 44 The unrecognized tax positions increase from prior periods for 2020 and the balance of unrecognized tax benefits at December 31, 2020 relate to a 2019 state tax filing position to exclude certain gains from 2019 dispositions from taxation in a certain unitary state. If accepted by the state, this position would decrease Southern Company's annual effective tax rate. The ultimate outcome of this unrecognized tax benefit is dependent on completion of the related state audit, which is not expected to be resolved within the next 12 months. All of the Registrants classify interest on tax uncertainties as interest expense. Accrued interest for all tax positions was immaterial for all years presented. None of the Registrants accrued any penalties on uncertain tax positions. The IRS has finalized its audits of Southern Company's consolidated federal income tax returns through 2019. Southern Company is a participant in the Compliance Assurance Process of the IRS. The audits for the Registrants' state income tax returns have either been concluded, or the statute of limitations has expired, for years prior to 2015. |
RETIREMENT BENEFITS
RETIREMENT BENEFITS | 12 Months Ended |
Dec. 31, 2020 | |
Retirement Benefits [Abstract] | |
RETIREMENT BENEFITS | RETIREMENT BENEFITS The Southern Company system has a qualified defined benefit, trusteed pension plan covering substantially all employees, with the exception of PowerSecure employees. The qualified pension plan is funded in accordance with requirements of the Employee Retirement Income Security Act of 1974, as amended (ERISA). No contributions to the qualified pension plan were made for the year ended December 31, 2020 and no mandatory contributions to the qualified pension plan are anticipated for the year ending December 31, 2021. The Southern Company system also provides certain non-qualified defined benefits for a select group of management and highly compensated employees, which are funded on a cash basis. In addition, the Southern Company system provides certain medical care and life insurance benefits for retired employees through other postretirement benefit plans. The traditional electric operating companies fund other postretirement trusts to the extent required by their respective regulatory commissions. Southern Company Gas has a separate unfunded supplemental retirement health care plan that provides medical care and life insurance benefits to employees of discontinued businesses. For the year ending December 31, 2021, no contributions to any other postretirement trusts are expected. On January 1, 2019, Southern Company completed the sale of Gulf Power to NextEra Energy. See Note 15 under "Southern Company" for additional information. All amounts presented in this note reflect the benefit plan obligations and related plan assets for the Southern Company system's pension and other postretirement benefit plans, including the amounts attributable to Gulf Power prior to January 1, 2019. Actuarial Assumptions The weighted average rates assumed in the actuarial calculations used to determine both the net periodic costs for the pension and other postretirement benefit plans for the following year and the benefit obligations as of the measurement date are presented below. 2020 Assumptions used to determine net Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas Pension plans Discount rate – benefit obligations 3.41 % 3.44 % 3.40 % 3.41 % 3.52 % 3.39 % Discount rate – interest costs 2.99 3.01 2.96 2.99 3.18 2.99 Discount rate – service costs 3.66 3.69 3.67 3.67 3.70 3.53 Expected long-term return on plan assets 8.25 8.25 8.25 8.25 8.25 8.25 Annual salary increase 4.73 4.73 4.73 4.73 4.73 4.73 Other postretirement benefit plans Discount rate – benefit obligations 3.24 % 3.28 % 3.22 % 3.22 % 3.39 % 3.19 % Discount rate – interest costs 2.80 2.84 2.79 2.76 2.97 2.71 Discount rate – service costs 3.57 3.61 3.57 3.57 3.57 3.52 Expected long-term return on plan assets 7.25 7.36 7.05 7.07 — 6.69 Annual salary increase 4.73 4.73 4.73 4.73 4.73 4.73 2019 Assumptions used to determine net Southern Company Alabama Georgia Mississippi Power Southern Power Southern Company Gas Pension plans Discount rate – benefit obligations 4.49 % 4.51 % 4.48 % 4.49 % 4.65 % 4.47 % Discount rate – interest costs 4.12 4.14 4.10 4.12 4.35 4.11 Discount rate – service costs 4.70 4.73 4.72 4.73 4.75 4.57 Expected long-term return on plan assets 7.75 7.75 7.75 7.75 7.75 7.75 Annual salary increase 4.34 4.46 4.46 4.46 4.46 3.07 Other postretirement benefit plans Discount rate – benefit obligations 4.37 % 4.40 % 4.36 % 4.35 % 4.50 % 4.32 % Discount rate – interest costs 3.98 4.01 3.97 3.95 4.14 3.91 Discount rate – service costs 4.63 4.67 4.64 4.64 4.65 4.56 Expected long-term return on plan assets 6.86 6.76 6.85 6.79 — 6.49 Annual salary increase 4.34 4.46 4.46 4.46 4.46 3.07 2018 Assumptions used to determine net periodic costs: Southern Company Alabama Georgia Mississippi Power Southern Power Southern Company Gas Pension plans Discount rate – benefit obligations 3.80 % 3.81 % 3.79 % 3.80 % 3.94 % 3.74 % Discount rate – interest costs 3.45 3.45 3.42 3.46 3.69 3.41 Discount rate – service costs 3.98 4.00 3.99 3.99 4.01 3.84 Expected long-term return on plan assets 7.95 7.95 7.95 7.95 7.95 7.95 Annual salary increase 4.34 4.46 4.46 4.46 4.46 3.07 Other postretirement benefit plans Discount rate – benefit obligations 3.68 % 3.71 % 3.68 % 3.68 % 3.81 % 3.62 % Discount rate – interest costs 3.29 3.31 3.29 3.29 3.47 3.21 Discount rate – service costs 3.91 3.93 3.91 3.91 3.93 3.82 Expected long-term return on plan assets 6.83 6.83 6.80 6.99 — 5.89 Annual salary increase 4.34 4.46 4.46 4.46 4.46 3.07 2020 Assumptions used to determine benefit obligations: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas Pension plans Discount rate 2.81 % 2.85 % 2.79 % 2.80 % 2.99 % 2.75 % Annual salary increase 4.80 4.80 4.80 4.80 4.80 4.80 Other postretirement benefit plans Discount rate 2.56 % 2.63 % 2.52 % 2.53 % 2.78 % 2.46 % Annual salary increase 4.80 4.80 4.80 4.80 4.80 4.80 2019 Assumptions used to determine benefit obligations: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas Pension plans Discount rate 3.41 % 3.44 % 3.40 % 3.41 % 3.52 % 3.39 % Annual salary increase 4.73 4.73 4.73 4.73 4.73 4.73 Other postretirement benefit plans Discount rate 3.24 % 3.28 % 3.22 % 3.22 % 3.39 % 3.19 % Annual salary increase 4.73 4.73 4.73 4.73 4.73 4.73 The Registrants estimate the expected rate of return on pension plan and other postretirement benefit plan assets using a financial model to project the expected return on each current investment portfolio. The analysis projects an expected rate of return on each of the different asset classes in order to arrive at the expected return on the entire portfolio relying on each trust's target asset allocation and reasonable capital market assumptions. The financial model is based on four key inputs: anticipated returns by asset class (based in part on historical returns), each trust's target asset allocation, an anticipated inflation rate, and the projected impact of a periodic rebalancing of each trust's portfolio. Prior to 2020, the Registrants set the expected rate of return assumption using asset return modeling based on geometric returns that reflect the compound average returns for dependent annual periods. Beginning in 2020, the Registrants set the expected rate of return assumption using an arithmetic mean which represents the expected simple average return to be earned by the pension plan assets over any one year. The Registrants believe the use of the arithmetic mean is more compatible with the expected rate of return's function of estimating a single year's investment return. An additional assumption used in measuring the accumulated other postretirement benefit obligations (APBO) was a weighted average medical care cost trend rate. The weighted average medical care cost trend rates used in measuring the APBO for the Registrants at December 31, 2020 were as follows: Initial Cost Trend Rate Ultimate Cost Trend Rate Year That Ultimate Rate is Reached Pre-65 6.00 % 4.50 % 2027 Post-65 medical 5.00 4.50 2027 Post-65 prescription 6.25 4.50 2028 Pension Plans The total accumulated benefit obligation for the pension plans at December 31, 2020 and 2019 was as follows: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) December 31, 2020 $ 14,922 $ 3,414 $ 4,657 $ 683 $ 175 $ 1,072 December 31, 2019 13,391 3,053 4,222 615 151 963 Actuarial losses of $1.7 billion and $2.3 billion were recorded in the remeasurement of the Southern Company system pension plans at December 31, 2020 and 2019, respectively, primarily due to decreases of 60 and 108 basis points, respectively, in the overall discount rate used to calculate the benefit obligation as a result of lower market interest rates. Changes in the projected benefit obligations and the fair value of plan assets during the plan years ended December 31, 2020 and 2019 were as follows: 2020 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Change in benefit obligation Benefit obligation at beginning of year $ 14,788 $ 3,404 $ 4,610 $ 671 $ 185 $ 1,067 Service cost 376 89 96 15 8 33 Interest cost 432 100 133 20 6 31 Benefits paid (629) (132) (202) (27) (6) (69) Actuarial (gain) loss 1,679 393 490 75 24 127 Balance at end of year 16,646 3,854 5,127 754 217 1,189 Change in plan assets Fair value of plan assets at beginning of year 14,057 3,357 4,442 641 169 1,050 Actual return (loss) on plan assets 1,881 450 594 85 22 139 Employer contributions 58 9 10 2 1 3 Benefits paid (629) (132) (202) (27) (6) (69) Fair value of plan assets at end of year 15,367 3,684 4,844 701 186 1,123 Accrued liability $ (1,279) $ (170) $ (283) $ (53) $ (31) $ (66) 2019 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Change in benefit obligation Benefit obligation at beginning of year $ 12,763 $ 2,816 $ 3,905 $ 557 $ 123 $ 907 Dispositions (509) — — — — — Service cost 292 69 74 12 7 25 Interest cost 492 114 156 22 5 36 Benefits paid (596) (125) (194) (26) (4) (64) Actuarial (gain) loss 2,346 530 669 106 54 163 Balance at end of year 14,788 3,404 4,610 671 185 1,067 Change in plan assets Fair value of plan assets at beginning of year 11,611 2,575 3,663 505 123 798 Dispositions (509) — — — — — Actual return (loss) on plan assets 2,343 524 730 103 43 172 Employer contributions 1,208 383 243 59 7 144 Benefits paid (596) (125) (194) (26) (4) (64) Fair value of plan assets at end of year 14,057 3,357 4,442 641 169 1,050 Accrued liability $ (731) $ (47) $ (168) $ (30) $ (16) $ (17) The projected benefit obligations for the qualified and non-qualified pension plans at December 31, 2020 are shown in the following table. All pension plan assets are related to the qualified pension plan. Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Projected benefit obligations: Qualified pension plan $ 15,818 $ 3,719 $ 4,977 $ 718 $ 187 $ 1,114 Non-qualified pension plan 828 135 150 36 30 75 Amounts recognized in the balance sheets at December 31, 2020 and 2019 related to the Registrants' pension plans consist of the following: Southern Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) December 31, 2020: Other regulatory assets, deferred (*) $ 4,655 $ 1,286 $ 1,598 $ 235 $ — $ 205 Other deferred charges and assets — — — — — 70 Other current liabilities (52) (9) (10) (2) (2) (2) Employee benefit obligations (1,227) (161) (273) (51) (29) (134) Other regulatory liabilities, deferred (34) — — — — — AOCI 245 — — — 60 1 December 31, 2019: Prepaid pension costs $ 2 $ 71 $ — $ 2 $ 10 $ — Other regulatory assets, deferred (*) 4,072 1,130 1,416 204 — 172 Other deferred charges and assets — — — — — 82 Other current liabilities (54) (8) (11) (2) (2) (2) Employee benefit obligations (679) (110) (157) (30) (24) (97) Other regulatory liabilities, deferred (79) — — — — — AOCI 185 — — — 46 (14) (*) Amounts for Southern Company exclude regulatory assets of $224 million and $252 million at December 31, 2020 and 2019, respectively, associated with unamortized amounts in Southern Company Gas' pension plans prior to its acquisition by Southern Company. Presented below are the amounts included in regulatory assets at December 31, 2020 and 2019 related to the portion of the defined benefit pension plan attributable to Southern Company, the traditional electric operating companies, and Southern Company Gas that had not yet been recognized in net periodic pension cost. Southern Alabama Power Georgia Mississippi Power Southern Company Gas (in millions) Balance at December 31, 2020 Regulatory assets: Prior service cost $ 11 $ 5 $ 9 $ 2 $ (13) Net (gain) loss 4,610 1,281 1,589 233 135 Regulatory amortization — — — — 83 Total regulatory assets (*) $ 4,621 $ 1,286 $ 1,598 $ 235 $ 205 Balance at December 31, 2019 Regulatory assets: Prior service cost $ 13 $ 6 $ 10 $ 2 $ (15) Net (gain) loss 3,980 1,124 1,406 201 113 Regulatory amortization — — — — 74 Total regulatory assets (*) $ 3,993 $ 1,130 $ 1,416 $ 203 $ 172 (*) Amounts for Southern Company exclude regulatory assets of $224 million and $252 million at December 31, 2020 and 2019, respectively, associated with unamortized amounts in Southern Company Gas' pension plans prior to its acquisition by Southern Company. The changes in the balance of regulatory assets related to the portion of the defined benefit pension plan attributable to Southern Company, the traditional electric operating companies, and Southern Company Gas for the years ended December 31, 2020 and 2019 are presented in the following table: Southern Alabama Power Georgia Mississippi Power Southern Company Gas (in millions) Regulatory assets (liabilities): (*) Balance at December 31, 2018 $ 3,458 $ 955 $ 1,230 $ 167 $ 160 Net (gain) loss 801 213 231 42 30 Dispositions (144) — — — — Reclassification adjustments: Amortization of prior service costs (3) (1) (1) — 2 Amortization of net gain (loss) (119) (37) (44) (6) — Amortization of regulatory assets (*) — — — — (20) Total reclassification adjustments (122) (38) (45) (6) (18) Total change 535 175 186 36 12 Balance at December 31, 2019 $ 3,993 $ 1,130 $ 1,416 $ 203 $ 172 Net (gain) loss 884 228 269 45 45 Reclassification adjustments: Amortization of prior service costs (1) (1) (1) — 2 Amortization of net gain (loss) (255) (71) (86) (13) (8) Amortization of regulatory assets (*) — — — — (6) Total reclassification adjustments (256) (72) (87) (13) (12) Total change 628 156 182 32 33 Balance at December 31, 2020 $ 4,621 $ 1,286 $ 1,598 $ 235 $ 205 (*) Amounts for Southern Company exclude regulatory assets of $224 million and $252 million at December 31, 2020 and 2019, respectively, associated with unamortized amounts in Southern Company Gas' pension plans prior to its acquisition by Southern Company. Presented below are the amounts included in AOCI at December 31, 2020 and 2019 related to the portion of the defined benefit pension plan attributable to Southern Company, Southern Power, and Southern Company Gas that had not yet been recognized in net periodic pension cost. Southern Southern Southern Company (in millions) Balance at December 31, 2020 AOCI: Prior service cost $ (3) $ — $ (4) Net (gain) loss 248 60 5 Total AOCI $ 245 $ 60 $ 1 Balance at December 31, 2019 AOCI: Prior service cost $ (3) $ — $ (6) Net (gain) loss 188 46 (8) Total AOCI $ 185 $ 46 $ (14) The components of OCI related to the portion of the defined benefit pension plan attributable to Southern Company, Southern Power, and Southern Company Gas for the years ended December 31, 2020 and 2019 are presented in the following table: Southern Company Southern Southern Company (in millions) AOCI: Balance at December 31, 2018 $ 97 $ 26 $ (44) Net (gain) loss 88 20 30 Balance at December 31, 2019 $ 185 $ 46 $ (14) Net (gain) loss 74 16 15 Reclassification adjustments: Amortization of prior service costs — — 1 Amortization of net gain (loss) (14) (2) (1) Total reclassification adjustments (14) (2) — Total change 60 14 15 Balance at December 31, 2020 $ 245 $ 60 $ 1 Components of net periodic pension cost for the Registrants were as follows: Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) 2020 Service cost $ 376 $ 89 $ 96 $ 15 $ 8 $ 33 Interest cost 432 100 133 20 6 31 Expected return on plan assets (1,100) (264) (347) (51) (13) (75) Recognized net (gain) loss 269 71 86 13 2 6 Net amortization 1 1 1 — — 15 Prior service cost — — — — — (3) Net periodic pension cost $ (22) $ (3) $ (31) $ (3) $ 3 $ 7 2019 Service cost $ 292 $ 69 $ 74 $ 12 $ 7 $ 25 Interest cost 492 114 156 22 5 36 Expected return on plan assets (885) (206) (292) (40) (10) (60) Recognized net (gain) loss 120 37 44 6 1 2 Net amortization 2 — 1 — — 14 Prior service cost — — — — — (3) Net periodic pension cost $ 21 $ 14 $ (17) $ — $ 3 $ 14 2018 Service cost $ 359 $ 78 $ 87 $ 17 $ 9 $ 34 Interest cost 464 101 139 20 5 39 Expected return on plan assets (943) (207) (296) (41) (10) (75) Recognized net (gain) loss 213 54 69 10 1 12 Net amortization 4 1 2 — — 15 Prior service cost — — — — — (2) Net periodic pension cost $ 97 $ 27 $ 1 $ 6 $ 5 $ 23 The service cost component of net periodic pension cost is included in operations and maintenance expenses and all other components of net periodic pension cost are included in other income (expense), net in the Registrants' statements of income. Net periodic pension cost is the sum of service cost, interest cost, and other costs netted against the expected return on plan assets. The expected return on plan assets is determined by multiplying the expected rate of return on plan assets and the market-related value of plan assets. In determining the market-related value of plan assets, the Registrants have elected to amortize changes in the market value of return-seeking plan assets over five years and to recognize the changes in the market value of liability-hedging plan assets immediately. Given the significant concentration in return-seeking plan assets, the accounting value of plan assets that is used to calculate the expected return on plan assets differs from the current fair value of the plan assets. Effective January 1, 2020, Southern Company changed its method of calculating the market-related value of the liability-hedging securities included in its pension plan assets. The market-related value is used to determine the expected return on plan assets component of net periodic pension cost. Southern Company previously used the calculated value approach for all plan assets, which smoothed asset returns and deferred gains and losses by amortizing them into the calculation of the market-related value over five years. Southern Company changed to the fair value approach for liability-hedging securities, which includes measuring the market-related value of that portion of the plan assets at fair value for purposes of determining the expected return on plan assets. The remaining asset classes of plan assets will continue to be valued using the calculated value approach. Southern Company considers the fair value approach to be preferable for liability-hedging securities because it results in a current reflection of changes in the value of plan assets in the measurement of net periodic pension cost more consistent with the change in the related obligations. Southern Company determined the effect of this change in accounting method was immaterial to the historical and current financial statements of all Registrants; therefore, the effect of the change was recorded through earnings as a prior period adjustment for the amounts related to the unregulated businesses of Southern Company and Southern Power. Amounts related to the traditional electric operating companies and the natural gas distribution utilities were reflected as adjustments to regulatory assets, consistent with the expected regulatory treatment. Future benefit payments reflect expected future service and are estimated based on assumptions used to measure the projected benefit obligation for the pension plans. At December 31, 2020, estimated benefit payments were as follows: Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Benefit Payments: 2021 $ 651 $ 141 $ 208 $ 29 $ 6 $ 66 2022 678 147 215 30 6 66 2023 702 154 222 31 6 66 2024 725 158 229 32 6 65 2025 748 165 235 33 7 65 2026 to 2030 4,024 895 1,244 181 38 330 Other Postretirement Benefits Changes in the APBO and the fair value of the Registrants' plan assets during the plan years ended December 31, 2020 and 2019 were as follows: 2020 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Change in benefit obligation Benefit obligation at beginning of year $ 1,985 $ 462 $ 742 $ 87 $ 11 $ 250 Service cost 22 6 6 1 1 2 Interest cost 54 13 20 2 — 7 Benefits paid (126) (29) (46) (6) — (17) Actuarial (gain) loss 7 9 (26) (3) — 6 Retiree drug subsidy 6 2 3 — — — Balance at end of year 1,948 463 699 81 12 248 Change in plan assets Fair value of plan assets at beginning of year 1,061 413 403 26 — 115 Actual return (loss) on plan assets 145 60 50 3 — 18 Employer contributions 72 12 17 4 — 12 Benefits paid (120) (27) (43) (6) — (17) Fair value of plan assets at end of year 1,158 458 427 27 — 128 Accrued liability $ (790) $ (5) $ (272) $ (54) $ (12) $ (120) 2019 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Change in benefit obligation Benefit obligation at beginning of year $ 1,865 $ 403 $ 675 $ 81 $ 9 $ 244 Dispositions (69) — — — — — Service cost 18 5 5 1 1 1 Interest cost 69 16 26 3 — 9 Benefits paid (126) (27) (47) (6) (1) (17) Actuarial (gain) loss 223 63 80 8 2 13 Retiree drug subsidy 5 2 3 — — — Balance at end of year 1,985 462 742 87 11 250 Change in plan assets Fair value of plan assets at beginning of year 928 360 344 23 — 98 Dispositions (18) — — — — — Actual return (loss) on plan assets 189 76 68 4 — 21 Employer contributions 83 2 35 5 1 13 Benefits paid (121) (25) (44) (6) (1) (17) Fair value of plan assets at end of year 1,061 413 403 26 — 115 Accrued liability $ (924) $ (49) $ (339) $ (61) $ (11) $ (135) Amounts recognized in the balance sheets at December 31, 2020 and 2019 related to the Registrants' other postretirement benefit plans consist of the following: Southern Company Alabama Power Georgia Mississippi Power Southern Southern Company Gas (in millions) December 31, 2020: Other regulatory assets, deferred (a) $ 137 $ — $ 47 $ 5 $ — $ (23) Other current liabilities (5) — — — — — Employee benefit obligations (b) (785) (5) (272) (54) (12) (120) Other regulatory liabilities, deferred (86) (21) — — — — AOCI 8 — — — 3 — December 31, 2019: Other regulatory assets, deferred (a) $ 183 $ 3 $ 96 $ 10 $ — $ (11) Other current liabilities (5) — — — — — Employee benefit obligations (b) (919) (49) (339) (61) (11) (135) Other regulatory liabilities, deferred (62) (2) — — — — AOCI 2 — — — 2 (4) (a) Amounts for Southern Company exclude regulatory assets of $47 million and $50 million at December 31, 2020 and 2019, respectively, associated with unamortized amounts in Southern Company Gas' other postretirement benefit plans prior to its acquisition by Southern Company. (b) Included in other deferred credits and liabilities on Southern Power's consolidated balance sheets. Presented below are the amounts included in net regulatory assets (liabilities) at December 31, 2020 and 2019 related to the other postretirement benefit plans of Southern Company, the traditional electric operating companies, and Southern Company Gas that had not yet been recognized in net periodic other postretirement benefit cost. Southern Company Alabama Power Georgia Mississippi Power Southern Company Gas (in millions) Balance at December 31, 2020: Regulatory assets (liabilities): Prior service cost $ 12 $ 3 $ 5 $ — $ 1 Net (gain) loss 39 (24) 42 5 (49) Regulatory amortization — — — — 25 Total regulatory assets (liabilities) (*) $ 51 $ (21) $ 47 $ 5 $ (23) Balance at December 31, 2019: Regulatory assets (liabilities): Prior service cost $ 11 $ 3 $ 4 $ — $ 1 Net (gain) loss 110 (2) 92 10 (43) Regulatory amortization — — — — 31 Total regulatory assets (liabilities) (*) $ 121 $ 1 $ 96 $ 10 $ (11) (*) Amounts for Southern Company exclude regulatory assets of $47 million and $50 million at December 31, 2020 and 2019, respectively, associated with unamortized amounts in Southern Company Gas' other postretirement benefit plans prior to its acquisition by Southern Company. The changes in the balance of net regulatory assets (liabilities) related to the other postretirement benefit plans for the plan years ended December 31, 2020 and 2019 are presented in the following table: Southern Company Alabama Power Georgia Mississippi Power Southern Company Gas (in millions) Net regulatory assets (liabilities): (*) Balance at December 31, 2018 $ 22 $ (9) $ 60 $ 4 $ (4) Net (gain) loss 90 14 37 6 (1) Dispositions 5 — — — — Change in prior service costs 5 — — — — Reclassification adjustments: Amortization of prior service costs (3) (4) — — — Amortization of net gain (loss) 2 — (1) — — Amortization of regulatory assets (*) — — — — (6) Total reclassification adjustments (1) (4) (1) — (6) Total change 99 10 36 6 (7) Balance at December 31, 2019 $ 121 $ 1 $ 96 $ 10 $ (11) Net (gain) loss (65) (22) (47) (5) (5) Reclassification adjustments: Amortization of prior service costs 1 — 1 — — Amortization of net gain (loss) (6) — (3) — — Amortization of regulatory assets (*) — — — — (7) Total reclassification adjustments (5) — (2) — (7) Total change (70) (22) (49) (5) (12) Balance at December 31, 2020 $ 51 $ (21) $ 47 $ 5 $ (23) (*) Amounts for Southern Company exclude regulatory assets of $47 million and $50 million at December 31, 2020 and 2019, respectively, associated with unamortized amounts in Southern Company Gas' other postretirement benefit plans prior to its acquisition by Southern Company. Presented below are the amounts included in AOCI at December 31, 2020 and 2019 related to the other postretirement benefit plans of Southern Company, Southern Power, and Southern Company Gas that had not yet been recognized in net periodic other postretirement benefit cost. Southern Southern Southern Company (in millions) Balance at December 31, 2020 AOCI: Prior service cost $ 1 $ — $ 1 Net (gain) loss 7 3 (1) Total AOCI $ 8 $ 3 $ — Balance at December 31, 2019 AOCI: Prior service cost $ 1 $ — $ 1 Net (gain) loss 1 2 (5) Total AOCI $ 2 $ 2 $ (4) The components of OCI related to the other postretirement benefit plans for the plan years ended December 31, 2020 and 2019 are presented in the following table: Southern Company Southern Southern Company Gas (in millions) AOCI: Balance at December 31, 2018 $ (4) $ 1 $ (4) Net (gain) loss 5 1 — Reclassification adjustments: Amortization of net gain (loss) 1 — — Total change 6 1 — Balance at December 31, 2019 $ 2 $ 2 $ (4) Net (gain) loss 2 1 — Reclassification adjustments: Amortization of net gain (loss) 4 — 4 Total change 6 1 4 Balance at December 31, 2020 $ 8 $ 3 $ — Components of the other postretirement benefit plans' net periodic cost for the Registrants were as follows: Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) 2020 Service cost $ 22 $ 6 $ 6 $ 1 $ 1 $ 2 Interest cost 54 13 20 2 — 7 Expected return on plan assets (72) (29) (26) (1) — (10) Net amortization 1 — 2 — — 6 Net periodic postretirement benefit cost $ 5 $ (10) $ 2 $ 2 $ 1 $ 5 2019 Service cost $ 18 $ 5 $ 5 $ 1 $ 1 $ 1 Interest cost 69 16 26 3 — 9 Expected return on plan assets (65) (26) (25) (2) — (7) Net amortization — 4 1 — — 6 Net periodic postretirement benefit cost $ 22 $ (1) $ 7 $ 2 $ 1 $ 9 2018 Service cost $ 24 $ 6 $ 6 $ 1 $ 1 $ 2 Interest cost 75 17 28 3 — 10 Expected return on plan assets (69) (26) (25) (2) — (7) Net amortization 21 5 10 1 — 6 Net periodic postretirement benefit cost $ 51 $ 2 $ 19 $ 3 $ 1 $ 11 The service cost component of net periodic postretirement benefit cost is included in operations and maintenance expenses and all other components of net periodic postretirement benefit cost are included in other income (expense), net in the Registrants' statements of income. The Registrants' future benefit payments, including prescription drug benefits, are provided in the table below. These amounts reflect expected future service and are estimated based on assumptions used to measure the APBO for the other postretirement benefit plans. Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Benefit payments: 2021 $ 115 $ 25 $ 42 $ 6 $ — $ 18 2022 113 25 41 5 — 18 2023 111 25 40 5 — 18 2024 110 24 38 4 1 17 2025 113 25 40 5 1 17 2026 to 2030 550 127 199 23 3 76 Benefit Plan Assets Pension plan and other postretirement benefit plan assets are managed and invested in accordance with all applicable requirements, including ERISA and the Internal Revenue Code. The Registrants' investment policies for both the pension plans and the other postretirement benefit plans cover a diversified mix of assets as described below. Derivative instruments may be used to gain efficient exposure to the various asset classes and as hedging tools. Additionally, the Registrants minimize the risk of large losses primarily through diversification but also monitor and manage other aspects of risk. The investment strategy for plan assets related to the Southern Company system's qualified pension plan is to be broadly diversified across major asset classes. The asset allocation is established after consideration of various factors that affect the assets and liabilities of the pension plan including, but not limited to, historical and expected returns and interest rates, volatility, correlations of asset classes, the current level of assets and liabilities, and the assumed growth in assets and liabilities. Because a significant portion of the liability of the pension plan is long-term in nature, the assets are invested consistent with long-term investment expectations for return and risk. To manage the actual asset class exposures relative to the target asset allocation, the Southern Company system employs a formal rebalancing program. As additional risk management, external investment managers and service providers are subject to written guidelines to ensure appropriate and prudent investment practices. Management believes the portfolio is well-diversified with no significant concentrations of risk. Investment Strategies and Benefit Plan Asset Fair Values A description of the major asset classes that the pension and other postretirement benefit plans are comprised of, along with the valuation methods used for fair value measurement, is provided below: Description Valuation Methodology Domestic equity: A mix of large and small capitalization stocks with generally an equal distribution of value and growth attributes, managed both actively and through passive index approaches. International equity: A mix of large and small capitalization growth and value stocks with developed and emerging markets exposure, managed both actively and through fundamental indexing approaches. Domestic and international equities such as common stocks, American depositary receipts, and real estate investment trusts that trade on public exchanges are classified as Level 1 investments and are valued at the closing price in the active market. Equity funds with unpublished prices that are comprised of publicly traded securities (such as commingled/pooled funds) are also valued at the closing price in the active market, but are classified as Level 2. Fixed income: A mix of domestic and international bonds. Investments in fixed income securities, including fixed income pooled funds, are generally classified as Level 2 investments and are valued based on prices reported in the market place. Additionally, the value of fixed income securities takes into consideration certain items such as broker quotes, spreads, yield curves, interest rates, and discount rates that apply to the term of a specific instrument. Trust-owned life insurance (TOLI): Investments of taxable trusts aimed at minimizing the impact of taxes on the portfolio. Investments in TOLI policies are classified as Level 2 investments and are valued based on the underlying investments held in the policy's separate accounts. The underlying assets are equity and fixed income pooled funds that are comprised of Level 1 and Level 2 securities. Special situations: Investments in opportunistic strategies with the objective of diversifying and enhancing returns and exploiting short-term inefficiencies, as well as investments in promising new strategies of a longer-term nature. Real estate: Investments in traditional private market, equity-oriented investments in real properties (indirectly through pooled funds or partnerships) and in publicly traded real estate securities. Private equity: Investments in private partnerships that invest in private or public securities typically through privately-negotiated and/or structured transactions, including leveraged buyouts, venture capital, and distressed debt. Investments in real estate, private equity, and special situations are generally classified as Net Asset Value as a Practical Expedient, since the underlying assets typically do not have publicly available observable inputs. The fund manager values the assets using va |
STOCK COMPENSATION
STOCK COMPENSATION | 12 Months Ended |
Dec. 31, 2020 | |
Share-based Payment Arrangement [Abstract] | |
STOCK COMPENSATION | STOCK COMPENSATION Stock-Based Compensation Stock-based compensation primarily in the form of Southern Company performance share units (PSU) and restricted stock units (RSU) may be granted through the Omnibus Incentive Compensation Plan to Southern Company system employees ranging from line management to executives. At December 31, 2020, the number of current and former employees participating in stock-based compensation programs for the Registrants was as follows: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas Number of employees 1,958 263 295 86 46 204 The majority of PSUs and RSUs awarded contain terms where employees become immediately vested in PSUs and RSUs upon retirement. As a result, compensation expense for employees that are retirement eligible at the grant date is recognized immediately, while compensation expense for employees that become retirement eligible during the vesting period is recognized over the period from grant date to the date of retirement eligibility. In addition, the Registrants recognize forfeitures as they occur. All unvested PSUs and RSUs vest immediately upon a change in control where Southern Company is not the surviving corporation. Performance Share Units PSUs granted to employees vest at the end of a three-year performance period. Shares of Southern Company common stock are delivered to employees at the end of the performance period with the number of shares issued ranging from 0% to 200% of the target number of PSUs granted, based on achievement of the performance goals established by the Compensation Committee of the Southern Company Board of Directors. Southern Company has issued three types of PSUs, each with a unique performance goal. These types of PSUs include total shareholder return (TSR) awards based on the TSR for Southern Company common stock during the three The fair value of TSR awards is determined as of the grant date using a Monte Carlo simulation model. In determining the fair value of the TSR awards issued to employees, the expected volatility is based on the historical volatility of Southern Company's stock over a period equal to the performance period. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant that covers the performance period of the awards. The following table shows the assumptions used in the pricing model and the weighted average grant-date fair value of TSR awards granted: Year Ended December 31 2020 2019 2018 Expected volatility 15.4% 15.6% 14.9% Expected term (in years) 3 3 3 Interest rate 1.4% 2.4% 2.4% Weighted average grant-date fair value $77.65 $62.71 $43.75 The Registrants recognize TSR award compensation expense on a straight-line basis over the three-year performance period without remeasurement. The fair values of EPS awards and ROE awards are based on the closing stock price of Southern Company common stock on the date of the grant. The weighted average grant-date fair value of the ROE awards granted during 2020, 2019, and 2018 was $68.42, $49.38, and $43.49, respectively. Compensation expense for EPS and ROE awards is generally recognized ratably over the three-year performance period adjusted for expected changes in EPS and ROE performance. Total compensation cost recognized for vested EPS awards and ROE awards reflects final performance metrics. Southern Company had 2.5 million unvested PSUs outstanding at December 31, 2019. In February 2020, the PSUs that vested for the three-year performance period ended December 31, 2019 were converted into 1.8 million shares outstanding at a share price of $68.59. During 2020, Southern Company granted 1.2 million PSUs and 1.5 million PSUs were vested or forfeited, resulting in 2.2 million unvested PSUs outstanding at December 31, 2020. In February 2021, the PSUs that vested for the three-year performance period ended December 31, 2020 were converted into 2.5 million shares outstanding at a share price of $60.10. Total PSU compensation cost, and the related tax benefit recognized in income, for the years ended December 31, 2020, 2019, and 2018 are as follows: 2020 2019 2018 (in millions) Southern Company Compensation cost recognized in income $ 84 $ 77 $ 91 Tax benefit of compensation cost recognized in income 22 20 24 Southern Company Gas Compensation cost recognized in income $ 13 $ 14 $ 11 Tax benefit of compensation cost recognized in income 4 4 3 Total PSU compensation cost and the related tax benefit recognized in income were immaterial for all periods presented for all other Registrants. The compensation cost related to the grant of Southern Company PSUs to the employees of each Subsidiary Registrant is recognized in each Subsidiary Registrant's financial statements with a corresponding credit to equity representing a capital contribution from Southern Company. At December 31, 2020, Southern Company's total unrecognized compensation cost related to PSUs was $32 million and is expected to be recognized over a weighted-average period of approximately 19 months. The total unrecognized compensation cost related to PSUs as of December 31, 2020 was immaterial for all other Registrants. Restricted Stock Units The fair value of RSUs is based on the closing stock price of Southern Company common stock on the date of the grant. The weighted average grant-date fair values of RSUs granted during 2020, 2019, and 2018 were $67.60, $50.44, and $43.81, respectively. For most RSU awards, one-third of the RSUs vest each year throughout a three-year service period and compensation cost for RSUs is generally recognized over the corresponding one two Southern Company had 1.3 million RSUs outstanding at December 31, 2019. During 2020, Southern Company granted 0.5 million RSUs and 0.6 million RSUs were vested or forfeited, resulting in 1.2 million unvested RSUs outstanding at December 31, 2020, including RSUs related to employee retention agreements. For the years ended December 31, 2020, 2019, and 2018, Southern Company's total compensation cost for RSUs recognized in income was $29 million, $28 million, and $27 million, respectively. The related tax benefit also recognized in income was $8 million, $7 million, and $7 million for the years ended December 31, 2020, 2019, and 2018, respectively. Total unrecognized compensation cost related to RSUs as of December 31, 2020 for Southern Company of $11 million will be recognized over a weighted-average period of approximately 18 months. Total RSUs outstanding and total compensation cost and related tax benefit for the RSUs recognized in income for the years ended December 31, 2020, 2019, and 2018, as well as the total unrecognized compensation cost as of December 31, 2020, were immaterial for all other Registrants. The compensation cost related to the grant of Southern Company RSUs to the employees of each Subsidiary Registrant is recognized in such Subsidiary Registrant's financial statements with a corresponding credit to equity representing a capital contribution from Southern Company. Stock Options In 2015, Southern Company discontinued granting stock options. As of December 31, 2017, all stock option awards were vested and compensation cost fully recognized. Stock options expire no later than 10 years after the grant date and the latest possible exercise will occur by November 2024. As of December 31, 2020, the weighted average remaining contractual term for the options outstanding and exercisable was approximately two years. Southern Company's activity in the stock option program for 2020 is summarized below: Shares Subject to Option Weighted Average Exercise Price (in millions) Outstanding at December 31, 2019 5.9 $ 42.52 Exercised 1.6 41.13 Outstanding and Exercisable at December 31, 2020 4.3 $ 43.04 Southern Company's cash receipts from issuances related to stock options exercised under the share-based payment arrangements for the years ended December 31, 2020, 2019, and 2018 were $66 million, $482 million, and $41 million, respectively. At December 31, 2020, the aggregate intrinsic value for the options outstanding and exercisable was as follows: Southern Company Alabama Power Georgia Power Southern Company Gas (in millions) Total intrinsic value for outstanding and exercisable options $ 78 $ 8 $ 25 $ 6 The aggregate intrinsic value for the options outstanding and exercisable was immaterial for Mississippi Power and Southern Power at December 31, 2020. Total intrinsic value of options exercised, and the related tax benefit, for the years ended December 31, 2020, 2019, and 2018 are presented below: Year Ended December 31 2020 2019 2018 (in millions) Southern Company Intrinsic value of options exercised $ 38 $ 167 $ 9 Tax benefit of options exercised 9 35 2 Alabama Power Intrinsic value of options exercised $ 5 $ 21 $ 2 Tax benefit of options exercised 1 4 — Georgia Power Intrinsic value of options exercised $ 9 $ 30 $ 2 Tax benefit of options exercised 2 6 — Total intrinsic value of options exercised, and the related tax benefit recognized in income, for the years ended December 31, 2020, 2019, and 2018 were immaterial for Mississippi Power, Southern Power, and Southern Company Gas. |
FAIR VALUE MEASUREMENTS
FAIR VALUE MEASUREMENTS | 12 Months Ended |
Dec. 31, 2020 | |
Fair Value Disclosures [Abstract] | |
FAIR VALUE MEASUREMENTS | FAIR VALUE MEASUREMENTS Fair value measurements are based on inputs of observable and unobservable market data that a market participant would use in pricing the asset or liability. The use of observable inputs is maximized where available and the use of unobservable inputs is minimized for fair value measurement and reflects a three-tier fair value hierarchy that prioritizes inputs to valuation techniques used for fair value measurement. • Level 1 consists of observable market data in an active market for identical assets or liabilities. • Level 2 consists of observable market data, other than that included in Level 1, that is either directly or indirectly observable. • Level 3 consists of unobservable market data. The input may reflect the assumptions of each Registrant of what a market participant would use in pricing an asset or liability. If there is little available market data, then each Registrant's own assumptions are the best available information. In the case of multiple inputs being used in a fair value measurement, the lowest level input that is significant to the fair value measurement represents the level in the fair value hierarchy in which the fair value measurement is reported. Net asset value as a practical expedient is the classification used for assets that do not have readily determined fair values. Fund managers value the assets using various inputs and techniques depending on the nature of the underlying investments. At December 31, 2020, assets and liabilities measured at fair value on a recurring basis during the period, together with their associated level of the fair value hierarchy, were as follows: Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2020: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Southern Company Assets: Energy-related derivatives (a) $ 401 $ 271 $ 32 $ — $ 704 Interest rate derivatives — 20 — — 20 Foreign currency derivatives — 87 — — 87 Investments in trusts: (b)(c) Domestic equity 862 151 — — 1,013 Foreign equity 85 253 — — 338 U.S. Treasury and government agency securities — 284 — — 284 Municipal bonds — 85 — — 85 Pooled funds – fixed income — 17 — — 17 Corporate bonds 13 386 — — 399 Mortgage and asset backed securities — 83 — — 83 Private equity — — — 76 76 Cash and cash equivalents 1 — — — 1 Other 28 7 — — 35 Cash equivalents 575 9 — — 584 Other investments 9 24 — — 33 Total $ 1,974 $ 1,677 $ 32 $ 76 $ 3,759 Liabilities: Energy-related derivatives (a) $ 389 $ 204 $ 4 $ — $ 597 Foreign currency derivatives — 23 — — 23 Contingent consideration — — 17 — 17 Total $ 389 $ 227 $ 21 $ — $ 637 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2020: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Alabama Power Assets: Energy-related derivatives $ — $ 12 $ — $ — $ 12 Nuclear decommissioning trusts: (b) Domestic equity 543 141 — — 684 Foreign equity 85 73 — — 158 U.S. Treasury and government agency securities — 21 — — 21 Municipal bonds — 1 — — 1 Corporate bonds 13 167 — — 180 Mortgage and asset backed securities — 29 — — 29 Private equity — — — 76 76 Other 7 — — — 7 Cash equivalents 311 9 — — 320 Other investments — 24 — — 24 Total $ 959 $ 477 $ — $ 76 $ 1,512 Liabilities: Energy-related derivatives $ — $ 7 $ — $ — $ 7 Georgia Power Assets: Energy-related derivatives $ — $ 15 $ — $ — $ 15 Nuclear decommissioning trusts: (b)(c) Domestic equity 319 1 — — 320 Foreign equity — 177 — — 177 U.S. Treasury and government agency securities — 263 — — 263 Municipal bonds — 84 — — 84 Corporate bonds — 219 — — 219 Mortgage and asset backed securities — 54 — — 54 Other 21 7 — — 28 Total $ 340 $ 820 $ — $ — $ 1,160 Liabilities: Energy-related derivatives $ — $ 13 $ — $ — $ 13 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2020: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Mississippi Power Assets: Energy-related derivatives $ — $ 9 $ — $ — $ 9 Cash equivalents 21 — — — 21 Total $ 21 $ 9 $ — $ — $ 30 Liabilities: Energy-related derivatives $ — $ 9 $ — $ — $ 9 Southern Power Assets: Energy-related derivatives $ — $ 2 $ — $ — $ 2 Foreign currency derivatives — 87 — — 87 Total $ — $ 89 $ — $ — $ 89 Liabilities: Energy-related derivatives $ — $ 3 $ — $ — $ 3 Foreign currency derivatives — 23 — — 23 Contingent consideration — — 17 — 17 Total $ — $ 26 $ 17 $ — $ 43 Southern Company Gas Assets: Energy-related derivatives (a) $ 401 $ 233 $ 32 $ — $ 666 Non-qualified deferred compensation trusts: Domestic equity — 9 — — 9 Foreign equity — 3 — — 3 Pooled funds - fixed income — 17 — — 17 Cash equivalents 1 — — — 1 Total $ 402 $ 262 $ 32 $ — $ 696 Liabilities: Energy-related derivatives (a)(b) $ 389 $ 172 $ 4 $ — $ 565 (a) Excludes $6 million associated with premiums and certain weather derivatives accounted for based on intrinsic value rather than fair value and cash collateral of $28 million. (b) Excludes receivables related to investment income, pending investment sales, payables related to pending investment purchases, and currencies. See Note 6 under "Nuclear Decommissioning" for additional information. (c) Includes investment securities pledged to creditors and collateral received and excludes payables related to the securities lending program. See Note 6 under "Nuclear Decommissioning" for additional information. At December 31, 2019, assets and liabilities measured at fair value on a recurring basis during the period, together with their associated level of the fair value hierarchy, were as follows: Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2019: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Southern Company Assets: Energy-related derivatives (a) $ 388 $ 267 $ 22 $ — $ 677 Interest rate derivatives — 2 — — 2 Foreign currency derivatives — 16 — — 16 Investments in trusts: (b)(c) Domestic equity 751 135 — — 886 Foreign equity 68 220 — — 288 U.S. Treasury and government agency securities — 307 — — 307 Municipal bonds — 85 — — 85 Pooled funds – fixed income — 17 — — 17 Corporate bonds 23 297 — — 320 Mortgage and asset backed securities — 87 — — 87 Private equity — — — 56 56 Cash and cash equivalents 1 — — — 1 Other 17 5 — — 22 Cash equivalents 1,393 2 — — 1,395 Other investments 9 21 — — 30 Total $ 2,650 $ 1,461 $ 22 $ 56 $ 4,189 Liabilities: Energy-related derivatives (a) $ 442 $ 254 $ 7 $ — $ 703 Interest rate derivatives — 24 — — 24 Foreign currency derivatives — 24 — — 24 Contingent consideration — — 19 — 19 Total $ 442 $ 302 $ 26 $ — $ 770 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2019: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Alabama Power Assets: Energy-related derivatives $ — $ 4 $ — $ — $ 4 Nuclear decommissioning trusts: (b) Domestic equity 488 123 — — 611 Foreign equity 68 64 — — 132 U.S. Treasury and government agency securities — 21 — — 21 Municipal bonds — 1 — — 1 Corporate bonds 23 144 — — 167 Mortgage and asset backed securities — 29 — — 29 Private equity — — — 56 56 Other 3 1 — — 4 Cash equivalents 691 2 — — 693 Other investments — 21 — — 21 Total $ 1,273 $ 410 $ — $ 56 $ 1,739 Liabilities: Energy-related derivatives $ — $ 24 $ — $ — $ 24 Georgia Power Assets: Energy-related derivatives $ — $ 4 $ — $ — $ 4 Nuclear decommissioning trusts: (b)(c) Domestic equity 263 1 — — 264 Foreign equity — 152 — — 152 U.S. Treasury and government agency securities — 286 — — 286 Municipal bonds — 84 — — 84 Corporate bonds — 153 — — 153 Mortgage and asset backed securities — 57 — — 57 Other 13 4 — — 17 Total $ 276 $ 741 $ — $ — $ 1,017 Liabilities: Energy-related derivatives $ — $ 53 $ — $ — $ 53 Interest rate derivatives — 17 — — 17 Total $ — $ 70 $ — $ — $ 70 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2019: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Mississippi Power Assets: Energy-related derivatives $ — $ 1 $ — $ — $ 1 Cash equivalents 281 — — — 281 Total $ 281 $ 1 $ — $ — $ 282 Liabilities: Energy-related derivatives $ — $ 27 $ — $ — $ 27 Southern Power Assets: Energy-related derivatives $ — $ 3 $ — $ — $ 3 Foreign currency derivatives — 16 — — 16 Cash equivalents 113 — — — 113 Total $ 113 $ 19 $ — $ — $ 132 Liabilities: Energy-related derivatives $ — $ 3 $ — $ — $ 3 Foreign currency derivatives — 24 — — 24 Contingent consideration — — 19 — 19 Total $ — $ 27 $ 19 $ — $ 46 Southern Company Gas Assets: Energy-related derivatives (a) $ 388 $ 255 $ 22 $ — $ 665 Interest rate derivatives — 2 — — 2 Non-qualified deferred compensation trusts: Domestic equity — 11 — — 11 Foreign equity — 4 — — 4 Pooled funds - fixed income — 17 — — 17 Cash equivalents 1 — — — 1 Cash equivalents 8 — — — 8 Total $ 397 $ 289 $ 22 $ — $ 708 Liabilities: Energy-related derivatives (a)(b) $ 442 $ 147 $ 7 $ — $ 596 (a) Excludes $4 million associated with premiums and certain weather derivatives accounted for based on intrinsic value rather than fair value and cash collateral of $99 million. (c) Excludes receivables related to investment income, pending investment sales, payables related to pending investment purchases, and currencies. See Note 6 under "Nuclear Decommissioning" for additional information. (d) Includes investment securities pledged to creditors and collateral received and excludes payables related to the securities lending program. See Note 6 under "Nuclear Decommissioning" for additional information. Valuation Methodologies The energy-related derivatives primarily consist of exchange-traded and over-the-counter financial products for natural gas and physical power products, including, from time to time, basis swaps. These are standard products used within the energy industry and are valued using the market approach. The inputs used are mainly from observable market sources, such as forward natural gas prices, power prices, implied volatility, and overnight index swap interest rates. Interest rate derivatives are also standard over-the-counter products that are valued using observable market data and assumptions commonly used by market participants. The fair value of interest rate derivatives reflects the net present value of expected payments and receipts under the swap agreement based on the market's expectation of future interest rates. Additional inputs to the net present value calculation may include the contract terms, counterparty credit risk, and occasionally, implied volatility of interest rate options. The fair value of cross-currency swaps reflects the net present value of expected payments and receipts under the swap agreement based on the market's expectation of future foreign currency exchange rates. Additional inputs to the net present value calculation may include the contract terms, counterparty credit risk, and discount rates. The interest rate derivatives and cross-currency swaps are categorized as Level 2 under Fair Value Measurements as these inputs are based on observable data and valuations of similar instruments. See Note 14 for additional information on how these derivatives are used. For fair value measurements of the investments within the nuclear decommissioning trusts and the non-qualified deferred compensation trusts, external pricing vendors are designated for each asset class with each security specifically assigned a primary pricing source. For investments held within commingled funds, fair value is determined at the end of each business day through the net asset value, which is established by obtaining the underlying securities' individual prices from the primary pricing source. A market price secured from the primary source vendor is then evaluated by management in its valuation of the assets within the trusts. As a general approach, fixed income market pricing vendors gather market data (including indices and market research reports) and integrate relative credit information, observed market movements, and sector news into proprietary pricing models, pricing systems, and mathematical tools. Dealer quotes and other market information, including live trading levels and pricing analysts' judgments, are also obtained when available. The NRC requires licensees of commissioned nuclear power reactors to establish a plan for providing reasonable assurance of funds for future decommissioning. See Note 6 under "Nuclear Decommissioning" for additional information. Southern Power has contingent payment obligations related to certain acquisitions whereby it is primarily obligated to make generation-based payments to the seller, which commenced at the commercial operation of the respective facility and continue through 2026. The obligations are categorized as Level 3 under Fair Value Measurements as the fair value is determined using significant unobservable inputs for the forecasted facility generation in MW-hours, as well as other inputs such as a fixed dollar amount per MW-hour, and a discount rate. The fair value of contingent consideration reflects the net present value of expected payments and any periodic change arising from forecasted generation is expected to be immaterial. "Other investments" include investments traded in the open market that have maturities greater than 90 days, which are categorized as Level 2 under Fair Value Measurements and are comprised of corporate bonds, bank certificates of deposit, treasury bonds, and/or agency bonds. The fair value measurements of private equity investments held in Alabama Power's nuclear decommissioning trusts that are calculated at net asset value per share (or its equivalent) as a practical expedient totaled $76 million and $56 million at December 31, 2020 and 2019, respectively. Unfunded commitments related to the private equity investments totaled $73 million and $70 million at December 31, 2020 and 2019, respectively. Private equity investments include high-quality private equity funds across several market sectors and funds that invest in real estate assets. Private equity funds do not have redemption rights. Distributions from these funds will be received as the underlying investments in the funds are liquidated. At December 31, 2020 and 2019, other financial instruments for which the carrying amount did not equal fair value were as follows: Southern Company (*) Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (*) (in millions) At December 31, 2020: Long-term debt, including securities due within one year: Carrying amount $ 48,349 $ 8,864 $ 12,825 $ 1,400 $ 3,692 $ 6,626 Fair value 56,264 10,702 15,198 1,590 4,165 7,973 At December 31, 2019: Long-term debt, including securities due within one year: Carrying amount $ 44,561 $ 8,517 $ 11,660 $ 1,589 $ 4,398 $ 5,845 Fair value 48,339 9,525 12,680 1,671 4,708 6,509 (*) The long-term debt of Southern Company Gas is recorded at amortized cost, including the fair value adjustments at the effective date of the 2016 merger with Southern Company. Southern Company Gas amortizes the fair value adjustments over the remaining lives of the respective bonds, the latest being through 2043. The fair values are determined using Level 2 measurements and are based on quoted market prices for the same or similar issues or on the current rates available to the Registrants. Commodity Contracts with Level 3 Valuation Inputs As of December 31, 2020, the fair value of Southern Company Gas' Level 3 physical natural gas forward contracts was $28 million. Since commodity contracts classified as Level 3 typically include a combination of observable and unobservable components, the changes in fair value may include amounts due in part to observable market factors, or changes to assumptions on the unobservable components. The following table includes transfers to Level 3, which represent the fair value of Southern Company Gas' commodity derivative contracts that include a significant unobservable component for the first time during the period. 2020 (in millions) Beginning balance $ 14 Transfers to Level 3 70 Transfers from Level 3 (34) Instruments realized or otherwise settled during period (16) Changes in fair value (6) Ending balance $ 28 Changes in fair value of Level 3 instruments represent changes in gains and losses for the periods that are reported on Southern Company Gas' statements of income in natural gas revenues. The valuation of certain commodity contracts requires the use of certain unobservable inputs. All forward pricing used in the valuation of such contracts is directly based on third-party market data, such as broker quotes and exchange settlements, when that data is available. If third-party market data is not available, then industry standard methodologies are used to develop inputs that maximize the use of relevant observable inputs and minimize the use of unobservable inputs. Observable inputs, including some forward prices used for determining fair value, reflect the best available market information. Unobservable inputs are updated using industry standard techniques such as extrapolation, combining observable forward inputs supplemented by historical market and other relevant data. Level 3 physical natural gas forward contracts include unobservable forward price inputs (ranging from $(0.08) to $0.24 per mmBtu). Forward price increases (decreases) as of December 31, 2020 would have resulted in higher (lower) values on a net basis. |
DERIVATIVES
DERIVATIVES | 12 Months Ended |
Dec. 31, 2020 | |
Derivative Instruments and Hedging Activities Disclosure [Abstract] | |
DERIVATIVES | DERIVATIVES Southern Company, the traditional electric operating companies, Southern Power, and Southern Company Gas are exposed to market risks, including commodity price risk, interest rate risk, weather risk, and occasionally foreign currency exchange rate risk. To manage the volatility attributable to these exposures, each company nets its exposures, where possible, to take advantage of natural offsets and enters into various derivative transactions for the remaining exposures pursuant to each company's policies in areas such as counterparty exposure and risk management practices. Southern Company Gas' wholesale gas operations use various contracts in its commercial activities that generally meet the definition of derivatives. For the traditional electric operating companies, Southern Power, and Southern Company Gas' other businesses, each company's policy is that derivatives are to be used primarily for hedging purposes and mandates strict adherence to all applicable risk management policies. Derivative positions are monitored using techniques including, but not limited to, market valuation, value at risk, stress testing, and sensitivity analysis. Derivative instruments are recognized at fair value in the balance sheets as either assets or liabilities and are presented on a net basis. See Note 13 for additional fair value information. In the statements of cash flows, any cash impacts of settled energy-related and interest rate derivatives are recorded as operating activities. Any cash impacts of settled foreign currency derivatives are classified as operating or financing activities to correspond with the classification of the hedged interest or principal, respectively. See Note 1 under "Financial Instruments" for additional information. Energy-Related Derivatives The traditional electric operating companies, Southern Power, and Southern Company Gas enter into energy-related derivatives to hedge exposures to electricity, natural gas, and other fuel price changes. However, due to cost-based rate regulations and other various cost recovery mechanisms, the traditional electric operating companies and the natural gas distribution utilities have limited exposure to market volatility in energy-related commodity prices. Each of the traditional electric operating companies and certain of the natural gas distribution utilities of Southern Company Gas manage fuel-hedging programs, implemented per the guidelines of their respective state PSCs or other applicable state regulatory agencies, through the use of financial derivative contracts, which are expected to continue to mitigate price volatility. The traditional electric operating companies (with respect to wholesale generating capacity) and Southern Power have limited exposure to market volatility in energy-related commodity prices because their long-term sales contracts shift substantially all fuel cost responsibility to the purchaser. However, the traditional electric operating companies and Southern Power may be exposed to market volatility in energy-related commodity prices to the extent any uncontracted capacity is used to sell electricity. Southern Company Gas retains exposure to price changes that can, in a volatile energy market, be material and can adversely affect its results of operations. Southern Company Gas also enters into weather derivative contracts as economic hedges of operating margins in the event of warmer-than-normal weather. Exchange-traded options are carried at fair value, with changes reflected in operating revenues. Non-exchange-traded options are accounted for using the intrinsic value method. Changes in the intrinsic value for non-exchange-traded contracts are reflected in operating revenues. Energy-related derivative contracts are accounted for under one of three methods: • Regulatory Hedges – Energy-related derivative contracts designated as regulatory hedges relate primarily to the traditional electric operating companies' and the natural gas distribution utilities' fuel-hedging programs, where gains and losses are initially recorded as regulatory liabilities and assets, respectively, and then are included in fuel expense as the underlying fuel is used in operations and ultimately recovered through an approved cost recovery mechanism. • Cash Flow Hedges – Gains and losses on energy-related derivatives designated as cash flow hedges (which are mainly used to hedge anticipated purchases and sales) are initially deferred in AOCI before being recognized in the statements of income in the same period and in the same income statement line item as the earnings effect of the hedged transactions. • Not Designated – Gains and losses on energy-related derivative contracts that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. Some energy-related derivative contracts require physical delivery as opposed to financial settlement, and this type of derivative is both common and prevalent within the electric and natural gas industries. When an energy-related derivative contract is settled physically, any cumulative unrealized gain or loss is reversed and the contract price is recognized in the respective line item representing the actual price of the underlying goods being delivered. At December 31, 2020, the net volume of energy-related derivative contracts for natural gas positions, together with the longest hedge date over which the respective entity is hedging its exposure to the variability in future cash flows for forecasted transactions and the longest non-hedge date for derivatives not designated as hedges, were as follows: Net Longest Longest (in millions) Southern Company (*) 835 2024 2031 Alabama Power 78 2024 — Georgia Power 135 2023 — Mississippi Power 89 2024 — Southern Power 10 2022 2021 Southern Company Gas (*) 523 2022 2031 (*) Southern Company Gas' derivative instruments include both long and short natural gas positions. A long position is a contract to purchase natural gas and a short position is a contract to sell natural gas. Southern Company Gas' volume represents the net of long natural gas positions of 4,421 million mmBtu and short natural gas positions of 3,898 million mmBtu at December 31, 2020, which is also included in Southern Company's total volume. At December 31, 2020, the net volume of Southern Power's energy-related derivative contracts for power to be sold was 1 million MWHs, all of which expire in 2021. In addition to the volumes discussed above, the traditional electric operating companies and Southern Power enter into physical natural gas supply contracts that provide the option to sell back excess natural gas due to operational constraints. The maximum expected volume of natural gas subject to such a feature is 29 million mmBtu for Southern Company, which includes 7 million mmBtu for Alabama Power, 9 million mmBtu for Georgia Power, 4 million mmBtu for Mississippi Power, and 9 million mmBtu for Southern Power. For cash flow hedges of energy-related derivatives, the estimated pre-tax gains (losses) expected to be reclassified from AOCI to earnings for the year ending December 31, 2021 are immaterial for all Registrants. Interest Rate Derivatives Southern Company and certain subsidiaries may enter into interest rate derivatives to hedge exposure to changes in interest rates. The derivatives employed as hedging instruments are structured to minimize ineffectiveness. Derivatives related to existing variable rate securities or forecasted transactions are accounted for as cash flow hedges where the derivatives' fair value gains or losses are recorded in OCI and are reclassified into earnings at the same time and presented on the same income statement line item as the earnings effect of the hedged transactions. Derivatives related to existing fixed rate securities are accounted for as fair value hedges, where the derivatives' fair value gains or losses and hedged items' fair value gains or losses are both recorded directly to earnings on the same income statement line item. Fair value gains or losses on derivatives that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. At December 31, 2020, the following interest rate derivatives were outstanding: Notional Interest Weighted Average Interest Hedge Fair Value (in millions) (in millions) Cash Flow Hedges of Existing Debt Mississippi Power $ 60 1-month LIBOR 0.58% December 2021 $ — Fair Value Hedges of Existing Debt Southern Company parent 1,500 2.35% 1-month LIBOR + 0.87% July 2021 20 Southern Company $ 1,560 $ 20 For cash flow hedge interest rate derivatives, the estimated pre-tax gains (losses) expected to be reclassified from AOCI to interest expense for the year ending December 31, 2021 total $(25) million for Southern Company and are immaterial for all other Registrants. Deferred gains and losses related to interest rate derivatives are expected to be amortized into earnings through 2046 for the Southern Company parent entity, 2035 for Alabama Power, 2044 for Georgia Power, 2028 for Mississippi Power, and 2046 for Southern Company Gas. Foreign Currency Derivatives Southern Company and certain subsidiaries, including Southern Power, may enter into foreign currency derivatives to hedge exposure to changes in foreign currency exchange rates, such as that arising from the issuance of debt denominated in a currency other than U.S. dollars. Derivatives related to forecasted transactions are accounted for as cash flow hedges where the derivatives' fair value gains or losses are recorded in OCI and are reclassified into earnings at the same time and on the same income statement line as the earnings effect of the hedged transactions, including foreign currency gains or losses arising from changes in the U.S. currency exchange rates. The derivatives employed as hedging instruments are structured to minimize ineffectiveness. At December 31, 2020, the following foreign currency derivatives were outstanding: Pay Notional Pay Rate Receive Notional Receive Rate Hedge Fair Value (in millions) (in millions) (in millions) Cash Flow Hedges of Existing Debt Southern Power $ 677 2.95% € 600 1.00% June 2022 $ 40 Southern Power 564 3.78% 500 1.85% June 2026 25 Total $ 1,241 € 1,100 $ 65 The estimated pre-tax gains (losses) related to Southern Power's foreign currency derivatives expected to be reclassified from AOCI to earnings for the year ending December 31, 2021 are $10 million. Derivative Financial Statement Presentation and Amounts Southern Company, the traditional electric operating companies, Southern Power, and Southern Company Gas enter into derivative contracts that may contain certain provisions that permit intra-contract netting of derivative receivables and payables for routine billing and offsets related to events of default and settlements. Southern Company and certain subsidiaries also utilize master netting agreements to mitigate exposure to counterparty credit risk. These agreements may contain provisions that permit netting across product lines and against cash collateral. The fair value amounts of derivative assets and liabilities on the balance sheets are presented net to the extent that there are netting arrangements or similar agreements with the counterparties. At December 31, 2020 and 2019, the fair value of energy-related derivatives, interest rate derivatives, and foreign currency derivatives was reflected in the balance sheets as follows: 2020 2019 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) Southern Company Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Assets from risk management activities/Other current liabilities $ 24 $ 11 $ 3 $ 70 Other deferred charges and assets/Other deferred credits and liabilities 18 19 6 44 Total derivatives designated as hedging instruments for regulatory purposes $ 42 $ 30 $ 9 $ 114 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Assets from risk management activities/Other current liabilities $ 3 $ 5 $ 1 $ 6 Interest rate derivatives: Assets from risk management activities/Other current liabilities 20 — 2 23 Other deferred charges and assets/Other deferred credits and liabilities — — — 1 Foreign currency derivatives: Assets from risk management activities/Other current liabilities — 23 — 24 Other deferred charges and assets/Other deferred credits and liabilities 87 — 16 — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 110 $ 28 $ 19 $ 54 Derivatives not designated as hedging instruments Energy-related derivatives: Assets from risk management activities/Other current liabilities $ 388 $ 331 $ 461 $ 358 Other deferred charges and assets/Other deferred credits and liabilities 270 232 207 225 Total derivatives not designated as hedging instruments $ 658 $ 563 $ 668 $ 583 Gross amounts recognized $ 810 $ 621 $ 696 $ 751 Gross amounts offset (a) $ (529) $ (557) $ (463) $ (562) Net amounts recognized in the Balance Sheets (b) $ 281 $ 64 $ 233 $ 189 2020 2019 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) Alabama Power Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets/Other current liabilities $ 7 $ 2 $ 2 $ 14 Other deferred charges and assets/Other deferred credits and liabilities 5 5 2 10 Total derivatives designated as hedging instruments for regulatory purposes $ 12 $ 7 $ 4 $ 24 Gross amounts recognized $ 12 $ 7 $ 4 $ 24 Gross amounts offset $ (7) $ (7) $ (2) $ (2) Net amounts recognized in the Balance Sheets $ 5 $ — $ 2 $ 22 Georgia Power Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets/Other current liabilities $ 7 $ 5 $ 1 $ 32 Other deferred charges and assets/Other deferred credits and liabilities 8 8 3 21 Total derivatives designated as hedging instruments for regulatory purposes $ 15 $ 13 $ 4 $ 53 Derivatives designated as hedging instruments in cash flow and fair value hedges Interest rate derivatives: Other current assets/Other current liabilities $ — $ — $ — $ 17 Gross amounts recognized $ 15 $ 13 $ 4 $ 70 Gross amounts offset $ (12) $ (12) $ (3) $ (3) Net amounts recognized in the Balance Sheets $ 3 $ 1 $ 1 $ 67 2020 2019 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) Mississippi Power Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets/Other current liabilities $ 4 $ 3 $ — $ 15 Other deferred charges and assets/Other deferred credits and liabilities 5 6 1 12 Total derivatives designated as hedging instruments for regulatory purposes $ 9 $ 9 $ 1 $ 27 Gross amounts recognized $ 9 $ 9 $ 1 $ 27 Gross amounts offset $ (7) $ (7) $ (1) $ (1) Net amounts recognized in the Balance Sheets $ 2 $ 2 $ — $ 26 Southern Power Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets/Other current liabilities $ 2 $ 2 $ 1 $ 2 Foreign currency derivatives: Other current assets/Other current liabilities — 23 — 24 Other deferred charges and assets/Other deferred credits and liabilities 87 — 16 — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 89 $ 25 $ 17 $ 26 Derivatives not designated as hedging instruments Energy-related derivatives: Other current assets/Other current liabilities $ — $ 1 $ 2 $ 1 Net amounts recognized in the Balance Sheets $ 89 $ 26 $ 19 $ 27 2020 2019 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) Southern Company Gas Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Assets from risk management activities/Other current liabilities $ 6 $ 1 $ — $ 9 Other deferred charges and assets/Other deferred credits and liabilities — — — 1 Total derivatives designated as hedging instruments for regulatory purposes $ 6 $ 1 $ — $ 10 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Assets from risk management activities/Other current liabilities $ 1 $ 3 $ — $ 4 Interest rate derivatives: Assets from risk management activities/Other current liabilities — — 2 — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 1 $ 3 $ 2 $ 4 Derivatives not designated as hedging instruments Energy-related derivatives: Assets from risk management activities/Other current liabilities $ 388 $ 330 $ 459 $ 357 Other deferred charges and assets/Other deferred credits and liabilities 270 232 207 225 Total derivatives not designated as hedging instruments $ 658 $ 562 $ 666 $ 582 Gross amounts recognized $ 665 $ 566 $ 668 $ 596 Gross amounts offset (a) $ (503) $ (531) $ (456) $ (555) Net amounts recognized in the Balance Sheets (b) $ 162 $ 35 $ 212 $ 41 (a) Gross amounts offset include cash collateral held on deposit in broker margin accounts of $28 million and $99 million at December 31, 2020 and 2019, respectively. (b) Net amounts of derivative instruments outstanding exclude immaterial premium and intrinsic value associated with weather derivatives for all periods presented. Energy-related derivatives not designated as hedging instruments were immaterial for the traditional electric operating companies at December 31, 2019. There were no such instruments for the traditional electric operating companies at December 31, 2020. At December 31, 2020 and 2019, the pre-tax effects of unrealized derivative gains (losses) arising from energy-related derivative instruments designated as regulatory hedging instruments and deferred were as follows: Regulatory Hedge Unrealized Gain (Loss) Recognized in the Balance Sheet at December 31, 2020 Derivative Category and Balance Sheet Southern Alabama Georgia Mississippi Southern Company Gas (in millions) Energy-related derivatives: Other regulatory assets, deferred $ (2) $ — $ (1) $ (1) $ — Other regulatory liabilities, current 12 5 2 1 4 Other regulatory liabilities, deferred 2 1 1 — — Total energy-related derivative gains (losses) $ 12 $ 6 $ 2 $ — $ 4 Regulatory Hedge Unrealized Gain (Loss) Recognized in the Balance Sheet at December 31, 2019 Derivative Category and Balance Sheet Southern Alabama Georgia Mississippi Southern Company Gas (in millions) Energy-related derivatives: Other regulatory assets, current $ (63) $ (14) $ (31) $ (15) $ (3) Other regulatory assets, deferred (37) (8) (18) (11) — Other regulatory liabilities, current 6 2 — — 4 Total energy-related derivative gains (losses) $ (94) $ (20) $ (49) $ (26) $ 1 For the years ended December 31, 2020, 2019, and 2018, the pre-tax effects of cash flow hedge accounting on AOCI for the applicable Registrants were as follows: Gain (Loss) Recognized in OCI on Derivative 2020 2019 2018 (in millions) Southern Company Energy-related derivatives $ (8) $ (13) $ 17 Interest rate derivatives (26) (57) (1) Foreign currency derivatives 48 (84) (78) Total $ 14 $ (154) $ (62) Georgia Power Interest rate derivatives $ (3) $ (59) $ — Southern Power Energy-related derivatives $ (2) $ (4) $ 10 Foreign currency derivatives 48 (84) (78) Total $ 46 $ (88) $ (68) Southern Company Gas Energy-related derivatives $ (6) $ (9) $ 7 Interest rate derivatives (23) 2 — Total $ (29) $ (7) $ 7 For all years presented, the pre-tax effects of interest rate derivatives designated as cash flow hedging instruments on AOCI were immaterial for the other Registrants. The pre-tax effects of cash flow and fair value hedge accounting on income for the years ended December 31, 2020, 2019, and 2018 were as follows: Location and Amount of Gain (Loss) Recognized in Income on Cash Flow and Fair Value Hedging Relationships 2020 2019 2018 (in millions) Southern Company Total cost of natural gas $ 972 $ 1,319 $ 1,539 Gain (loss) on energy-related cash flow hedges (a) (8) (2) 2 Total depreciation and amortization 3,518 3,038 3,131 Gain (loss) on energy-related cash flow hedges (a) (3) (6) 7 Total interest expense, net of amounts capitalized (1,821) (1,736) (1,842) Gain (loss) on interest rate cash flow hedges (a) (26) (20) (21) Gain (loss) on foreign currency cash flow hedges (a) (23) (24) (24) Gain (loss) on interest rate fair value hedges (b) 27 42 (12) Total other income (expense), net 336 252 114 Gain (loss) on foreign currency cash flow hedges (a)(c) 114 (24) (60) Southern Power Total depreciation and amortization $ 494 $ 479 $ 493 Gain (loss) on energy-related cash flow hedges (a) (3) (6) 7 Total interest expense, net of amounts capitalized (151) (169) (183) Gain (loss) on foreign currency cash flow hedges (a) (23) (24) (24) Total other income (expense), net 19 47 23 Gain (loss) on foreign currency cash flow hedges (a)(c) 114 (24) (60) (a) Reclassified from AOCI into earnings. (b) For fair value hedges, changes in the fair value of the derivative contracts are generally equal to changes in the fair value of the underlying debt and have no material impact on income. (c) The reclassification from AOCI into other income (expense), net completely offsets currency gains and losses arising from changes in the U.S. currency exchange rates used to record the euro-denominated notes. The pre-tax effects of cash flow hedge accounting on income for interest rate derivatives and energy-related derivatives were immaterial for the other Registrants for all years presented. At December 31, 2020 and 2019, the following amounts were recorded on the balance sheets related to cumulative basis adjustments for fair value hedges: Carrying Amount of the Hedged Item Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item Balance Sheet Location of Hedged Items At December 31, 2020 At December 31, 2019 At December 31, 2020 At December 31, 2019 (in millions) (in millions) Southern Company Securities due within one year $ (1,509) $ (599) $ (10) $ — Long-term debt — (1,494) — 3 The pre-tax effects of energy-related derivatives not designated as hedging instruments on the statements of income of Southern Company and Southern Company Gas for the years ended December 31, 2020, 2019, and 2018 were as follows: Gain (Loss) Derivatives in Non-Designated Hedging Relationships Statements of Income Location 2020 2019 2018 (in millions) Energy-related derivatives Natural gas revenues (*) $ 134 $ 223 $ (122) Cost of natural gas 15 10 (6) Total derivatives in non-designated hedging relationships $ 149 $ 233 $ (128) (*) Excludes the impact of weather derivatives recorded in natural gas revenues of $9 million, $3 million, and $5 million for the years ended December 31, 2020, 2019, and 2018, respectively, as they are accounted for based on intrinsic value rather than fair value. The pre-tax effects of energy-related derivatives not designated as hedging instruments were immaterial for all other Registrants for all years presented. Contingent Features Southern Company, the traditional electric operating companies, Southern Power, and Southern Company Gas do not have any credit arrangements that would require material changes in payment schedules or terminations as a result of a credit rating downgrade. There are certain derivatives that could require collateral, but not accelerated payment, in the event of various credit rating changes of certain Southern Company subsidiaries. At December 31, 2020, the Registrants had no collateral posted with derivative counterparties to satisfy these arrangements. For the Registrants with interest rate derivatives at December 31, 2020, there were no interest rate derivative liabilities with contingent features. At December 31, 2020, the fair value of energy-related derivative liabilities with contingent features and the maximum potential collateral requirements arising from the credit-risk-related contingent features, at a rating below BBB- and/or Baa3, were immaterial for all Registrants. The maximum potential collateral requirements arising from the credit-risk-related contingent features for the traditional electric operating companies and Southern Power include certain agreements that could require collateral in the event that one or more Southern Company power pool participants has a credit rating change to below investment grade. Following the sale of Gulf Power to NextEra Energy, Gulf Power is continuing to participate in the Southern Company power pool for a defined transition period that, subject to certain potential adjustments, is scheduled to end on January 1, 2024. Generally, collateral may be provided by a Southern Company guaranty, letter of credit, or cash. If collateral is required, fair value amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral are not offset against fair value amounts recognized for derivatives executed with the same counterparty. Alabama Power and Southern Power maintain accounts with certain regional transmission organizations to facilitate financial derivative transactions and they may be required to post collateral based on the value of the positions in these accounts and the associated margin requirements. At December 31, 2020, cash collateral posted in these accounts was immaterial. Southern Company Gas maintains accounts with brokers or the clearing houses of certain exchanges to facilitate financial derivative transactions. Based on the value of the positions in these accounts and the associated margin requirements, Southern Company Gas may be required to deposit cash into these accounts. At December 31, 2020, cash collateral held on deposit in broker margin accounts was $28 million. The Registrants are exposed to losses related to financial instruments in the event of counterparties' nonperformance. The Registrants only enter into agreements and material transactions with counterparties that have investment grade credit ratings by Moody's and S&P or with counterparties who have posted collateral to cover potential credit exposure. The Registrants have also established risk management policies and controls to determine and monitor the creditworthiness of counterparties in order to mitigate their exposure to counterparty credit risk. Southern Company Gas uses established credit policies to determine and monitor the creditworthiness of counterparties, including requirements to post collateral or other credit security, as well as the quality of pledged collateral. Collateral or credit security is most often in the form of cash or letters of credit from an investment-grade financial institution, but may also include cash or U.S. government securities held by a trustee. Prior to entering a physical transaction, Southern Company Gas assigns its counterparties an internal credit rating and credit limit based on the counterparties' Moody's, S&P, and Fitch ratings, commercially available credit reports, and audited financial statements. Southern Company Gas may require counterparties to pledge additional collateral when deemed necessary. Southern Company Gas utilizes netting agreements whenever possible to mitigate exposure to counterparty credit risk. Netting agreements enable Southern Company Gas to net certain assets and liabilities by counterparty across product lines and against cash collateral, provided the netting and cash collateral agreements include such provisions. While the amounts due from, or owed to, counterparties are settled net, they are recorded on a gross basis on the balance sheet as energy marketing receivables and energy marketing payables. The Registrants do not anticipate a material adverse effect on their respective financial statements as a result of counterparty nonperformance. |
ACQUISITIONS AND DISPOSITIONS
ACQUISITIONS AND DISPOSITIONS | 12 Months Ended |
Dec. 31, 2020 | |
Business Combinations [Abstract] | |
ACQUISITIONS AND DISPOSITIONS | ACQUISITIONS AND DISPOSITIONS Southern Company In January 2019, Southern Company completed the sale of all of the capital stock of Gulf Power to a wholly-owned subsidiary of NextEra Energy, for an aggregate cash purchase price of approximately $5.8 billion (less $1.3 billion of indebtedness assumed), including the final working capital adjustments. The gain associated with the sale of Gulf Power totaled $2.6 billion pre-tax ($1.4 billion after tax). In July 2019, PowerSecure completed the sale of its utility infrastructure services business for approximately $65 million, including the final working capital adjustments. In contemplation of this sale, a goodwill impairment charge of $32 million was recorded in the second quarter 2019. In December 2019, PowerSecure completed the sale of its lighting business for approximately $9 million, which included cash of $4 million and a note receivable from the buyer of $5 million. In contemplation of this sale, an impairment charge of $18 million was recorded in the third quarter 2019 related to goodwill, identifiable intangibles, and other assets. In December 2019, Southern Company completed the sale of one of its leveraged lease investments for an aggregate cash purchase price of approximately $20 million. The sale resulted in an immaterial gain. During the fourth quarter 2020, management of Southern Company initiated steps to sell one of its leveraged leases and classified the investment in the leveraged lease as held for sale on Southern Company's balance sheet as of December 31, 2020. The ultimate outcome of this matter cannot be determined at this time. See Note 3 under "Other Matters – Southern Company" and "Assets Held for Sale" herein for additional information. Southern Power Southern Power's acquisition-related costs for the projects discussed under "Asset Acquisitions" and "Construction Projects" below were expensed as incurred and were not material for any of the years presented. Asset Acquisitions Project Resource Seller Approximate Nameplate Capacity ( MW ) Location Southern COD PPA Contract Period Asset Acquisitions During 2020 Beech Ridge II Wind Invenergy Renewables LLC 56 Greenbrier County, WV 100% of Class A (a) May 12 years Asset Acquisitions During 2019 DSGP (b) Fuel Cell Bloom Energy 28 Delaware 100% of Class B N/A (c) 15 years (d) Asset Acquisitions During 2018 Gaskell West 1 Solar Recurrent Energy Development Holdings, LLC 20 Kern County, CA 100% of Class B (e) March 2018 20 years (a) In May 2020, Southern Power purchased a controlling interest and now consolidates the project's operating results in its financial statements. The Class B member owns the noncontrolling interest. (b) During 2019, Southern Power purchased a controlling interest and now consolidates the project's operating results in its financial statements. The Class A and Class C members each own a noncontrolling interest. Southern Power records net income attributable to noncontrolling interests for approximately 10 MWs of the facility. (c) Southern Power's 18-MW share of the facility was repowered between June and August 2019. In December 2019, a Class C member joined the existing partnership between the Class A member and Southern Power and made an investment to repower the remaining 10 MWs. (d) Remaining PPA contract period at the time of acquisition. (e) Southern Power owns a controlling interest under a tax equity partnership. In March 2020, Southern Power entered into an agreement to acquire a controlling membership interest in an approximately 300-MW wind facility located in South Dakota. The acquisition is subject to certain customary conditions to closing, including commercial operation of the facility, which is expected to occur in the first quarter 2021. Subsequent to the acquisition, Southern Power expects to complete a tax equity transaction. The facility's output is contracted under two long-term PPAs. The ultimate outcome of this matter cannot be determined at this time. Construction Projects During 2020, Southern Power completed construction of and placed in service the Reading and Skookumchuck wind facilities, commenced construction of the Garland and Tranquillity battery energy storage facilities, and acquired and commenced construction of the Glass Sands wind facility. Total aggregate construction costs, excluding acquisition costs, are expected to be between $392 million and $460 million for the facilities under construction. At December 31, 2020, the total costs of construction incurred and included in CWIP for these projects were $34 million. The ultimate outcome of these matters cannot be determined at this time. Project Resource Approximate Nameplate Capacity ( MW ) Location Actual/Expected PPA Contract Period Projects Under Construction at December 31, 2020 Garland Solar Storage (a) Battery energy storage system 88 Kern County, CA Third quarter 2021 20 years Tranquillity Solar Storage (a) Battery energy storage system 72 Fresno County, CA Fourth quarter 2021 20 years Glass Sands (b) Wind 118 Murray County, OK Fourth quarter 2021 12 years Projects Completed During 2020 Skookumchuck (c) Wind 136 Lewis and Thurston Counties, WA November 2020 20 years Reading (d) Wind 200 Osage and Lyon Counties, KS May 2020 12 years Projects Completed During 2019 (e) Wildhorse Mountain (f) Wind 100 Pushmataha County, OK December 2019 20 years (a) In December 2020, Southern Power restructured its ownership of the project by contributing the Class A membership interests to an existing partnership and selling 100% of the Class B membership interests while retaining the controlling interest. Prior to commercial operation, Southern Power may restructure the project ownership again and enter into additional partnerships, but expects to retain the controlling interest. The ultimate outcome of this matter cannot be determined at this time. (b) In December 2020, Southern Power purchased 100% of the membership interests of the Glass Sands facility. (c) In October 2019, Southern Power purchased 100% of the membership interests of the Skookumchuck facility pursuant to a joint development arrangement. In November 2020, Southern Power completed a tax equity transaction whereby it received $121 million, resulting in 100% ownership of the Class B membership interests. Southern Power subsequently sold a noncontrolling interest in the Class B membership interests and now retains the controlling ownership interest in the facility. (d) In 2018, Southern Power purchased 100% of the membership interests of the Reading facility pursuant to a joint development arrangement. In June 2020, Southern Power completed a tax equity transaction whereby it received $156 million and owns 100% of the Class B membership interests. (e) During 2019, Southern Power also completed the expansion of Plant Mankato, which was sold to a subsidiary of Xcel on January 17, 2020. See "Sales of Natural Gas and Biomass Plants" below for additional information. (f) In 2018, Southern Power purchased 100% of the membership interests of the Wildhorse Mountain facility. In December 2019, Southern Power entered into a tax equity partnership and owns 100% of the Class B membership interests. Development Projects Southern Power continues to evaluate and refine the deployment of the remaining wind turbine equipment purchased in 2016 and 2017 to development and construction projects. Wind projects utilizing equipment purchased in 2016 and 2017, and reaching commercial operation by the end of 2021 and 2022, are expected to qualify for 100% and 80% PTCs, respectively. The significant majority of this equipment either has been deployed to projects that have been completed, are under construction, or are probable of completion, or has been sold to third parties. In 2018, as a result of a review of various options for probable dispositions of wind turbine equipment not deployed to development or construction projects, Southern Power recorded a $36 million asset impairment charge on the equipment. Gains on equipment sales were immaterial in 2020 and totaled approximately $17 million in 2019. Sales of Renewable Facility Interests In May 2018, Southern Power completed the sale of a noncontrolling 33% equity interest in SP Solar, a limited partnership indirectly owning substantially all of Southern Power's solar facilities, to Global Atlantic for approximately $1.2 billion. Since Southern Power retained control of the limited partnership, the sale was recorded as an equity transaction. On the date of the transaction, the noncontrolling interest was increased by $511 million to reflect 33% of the carrying value of the partnership. This difference, partially offset by the tax impact and other related transaction charges, also resulted in a $410 million decrease to Southern Power's common stockholder's equity. In December 2018, Southern Power completed the sale of a noncontrolling tax equity interest in SP Wind, which owns a portfolio of eight operating wind facilities, to three financial investors for approximately $1.2 billion. The tax equity investors together will generally receive 40% of the cash distributions from available cash and will receive 99% of the tax attributes, including future PTCs. Southern Power consolidates each entity, as the primary beneficiary of the VIE, since it controls the most significant activities, including operating and maintaining the assets. Sales of Natural Gas and Biomass Plants In December 2018, Southern Power completed the sale of all of its equity interests in Plant Oleander and Plant Stanton Unit A (together, the Florida Plants) to NextEra Energy for $203 million, including final working capital adjustments. In contemplation of this sale transaction, Southern Power recorded an asset impairment charge of approximately $119 million ($89 million after tax) in the second quarter 2018. In June 2019, Southern Power completed the sale of its equity interests in Plant Nacogdoches, a 115-MW biomass facility located in Nacogdoches County, Texas, to Austin Energy, for a purchase price of approximately $461 million, including final working capital adjustments. Southern Power recorded a gain of $23 million ($88 million after tax) on the sale. On January 17, 2020, Southern Power completed the sale of its equity interests in Plant Mankato (including the 385-MW expansion unit completed in May 2019) to a subsidiary of Xcel for a purchase price of approximately $663 million, including final working capital adjustments. The sale resulted in a gain of approximately $39 million ($23 million after tax). The assets and liabilities of Plant Mankato were classified as held for sale on Southern Company's and Southern Power's balance sheets at December 31, 2019. See "Assets Held for Sale" herein for additional information. Southern Company Gas Sale of Pivotal Home Solutions In June 2018, Southern Company Gas completed the stock sale of Pivotal Home Solutions to American Water Enterprises LLC for a total cash purchase price of $365 million, which includes the final working capital adjustment. This disposition resulted in a net loss of $67 million, which includes $34 million of income tax expense. In contemplation of the transaction, a goodwill impairment charge of $42 million was recorded during 2018. The income tax expense included tax on goodwill not deductible for tax purposes and for which a deferred tax liability had not been recorded previously. Southern Company Gas and American Water Enterprises LLC entered into a transition services agreement whereby Southern Company Gas provided certain administrative and operational services, which ended during 2018. Sales of Elizabethtown Gas and Elkton Gas In July 2018, a Southern Company Gas subsidiary, Pivotal Utility Holdings, completed the sales of the assets of two of its natural gas distribution utilities, Elizabethtown Gas and Elkton Gas, to South Jersey Industries, Inc. for a total cash purchase price of $1.7 billion, which includes the final working capital and other adjustments. This disposition resulted in a pre-tax gain that was entirely offset by $205 million of income tax expense, resulting in no material net income impact. The income tax expense included tax on goodwill not deductible for tax purposes and for which a deferred tax liability had not been recorded previously. Southern Company Gas and South Jersey Industries, Inc. entered into transition services agreements whereby Southern Company Gas provided certain administrative and operational services through July 2, 2020. Sale of Florida City Gas In July 2018, Southern Company Gas and its wholly-owned direct subsidiary, NUI Corporation, completed the stock sale of Pivotal Utility Holdings, which primarily consisted of Florida City Gas, to NextEra Energy for a total cash purchase price of $587 million, which includes the final working capital adjustment. This disposition resulted in a net gain of $16 million, which includes $103 million of income tax expense. The income tax expense included tax on goodwill not deductible for tax purposes and for which a deferred tax liability had not been recorded previously. Southern Company Gas and NextEra Energy entered into a transition services agreement whereby Southern Company Gas provided certain administrative and operational services through July 28, 2020. Sale of Triton In May 2019, Southern Company Gas sold its investment in Triton, a cargo container leasing company that was aggregated into Southern Company Gas' all other segment. This disposition resulted in a pre-tax loss of $6 million and a net after-tax gain of $7 million as a result of reversing a $13 million federal income tax valuation allowance. Sale of Pivotal LNG and Atlantic Coast Pipeline On March 24, 2020, Southern Company Gas completed the sale of its interests in Pivotal LNG and Atlantic Coast Pipeline to Dominion Modular LNG Holdings, Inc. and Dominion Atlantic Coast Pipeline, LLC, respectively, with aggregate proceeds of $178 million, including final working capital adjustments. The loss associated with the transactions was immaterial. Southern Company Gas also expects to receive payments in April 2021 and August 2021 of $5 million each contingent upon Dominion Modular LNG Holdings, Inc. meeting certain milestones related to Pivotal LNG. During 2019, based on the terms of these transactions, Southern Company Gas recorded an asset impairment charge, exclusive of the contingent payments, for Pivotal LNG of approximately $24 million ($17 million after tax) as of December 31, 2019. The assets and liabilities of Pivotal LNG and the interest in Atlantic Coast Pipeline were classified as held for sale as of December 31, 2019. See Note 7 under "Southern Company Gas" and "Assets Held for Sale" herein for additional information. Sale of Natural Gas Storage Facility On December 1, 2020, Southern Company Gas completed the sale of Jefferson Island to EnLink Midstream, LLC for a total purchase price of $33 million, including estimated working capital adjustments. The gain associated with the sale totaled $22 million pre-tax ($16 million after tax). Assets Held for Sale Assets and liabilities held for sale have been classified separately on each company's balance sheet at the lower of carrying value or fair value less costs to sell at the time the criteria for held-for-sale classification were met. For assets and liabilities held for sale recorded at fair value on a nonrecurring basis, the fair value of assets held for sale is based primarily on unobservable inputs (Level 3), which includes the agreed upon sales prices in executed sales agreements. Since the depreciation of the assets sold in the Gulf Power transaction and Southern Company Gas' Elizabethtown Gas, Elkton Gas, and Florida City Gas transactions continued to be reflected in customer rates through the closing date of each sale and was reflected in the carryover basis of the assets when sold, Southern Company and Southern Company Gas continued to record depreciation on those assets through the respective closing date of each transaction. Upon classification as held for sale in May 2018 for the Florida Plants, November 2018 for Plant Mankato, and April 2019 for Plant Nacogdoches, Southern Power ceased recognizing depreciation and amortization on the long-lived assets being sold. The following table provides the major classes of assets and liabilities classified as held for sale for Southern Company, Southern Power, and Southern Company Gas at December 31, 2020 and/or 2019: Southern Southern Southern Company Gas At December 31, At December 31, At December 31, 2020 2019 2019 2019 (in millions) Assets Held for Sale: Current assets $ — $ 19 $ 17 $ 2 Total property, plant, and equipment 8 565 547 18 Goodwill and other intangible assets — 40 40 — Equity investments in unconsolidated subsidiaries — 151 — 151 Leveraged leases 52 — — — Other non-current assets — 14 14 — Total Assets Held for Sale $ 60 $ 789 $ 618 $ 171 Liabilities Held for Sale (all current): $ — $ 5 $ 3 $ 2 Southern Company, Southern Power, and Southern Company Gas each concluded that the asset sales, both individually and combined, did not represent a strategic shift in operations that has, or is expected to have, a major effect on its operations and financial results; therefore, none of the assets related to the sales have been classified as discontinued operations for any of the periods presented. Gulf Power and Southern Power's Florida Plants, Plant Nacogdoches, and Plant Mankato represented individually significant components of Southern Company and Southern Power, respectively. Pre-tax income for these components for the years ended December 31, 2020, 2019, and 2018 are presented below: 2020 2019 2018 (in millions) Earnings before income taxes: Gulf Power N/A N/A $ 140 Southern Power's Florida Plants (a)(b) N/A N/A $ 49 Southern Power's Plant Nacogdoches (a)(c) N/A $ 13 $ 27 Southern Power's Plant Mankato (a)(d) $ 2 $ 29 N/M N/M - Not material (a) Earnings before income taxes reflect the cessation of depreciation and amortization on the long-lived assets being sold upon classification as held for sale. (b) 2018 amount represents the period from January 1, 2018 to December 4, 2018 (the divestiture date). (c) 2019 amount represents the period from January 1, 2019 to June 13, 2019 (the divestiture date). (d) 2020 amount represents the period from January 1, 2020 to January 17, 2020 (the divestiture date). |
SEGMENT AND RELATED INFORMATION
SEGMENT AND RELATED INFORMATION (Notes) | 12 Months Ended |
Dec. 31, 2020 | |
Segment Reporting [Abstract] | |
SEGMENT AND RELATED INFORMATION | SEGMENT AND RELATED INFORMATION Southern Company Southern Company's reportable business segments are the sale of electricity by the traditional electric operating companies, the sale of electricity in the competitive wholesale market by Southern Power, and the sale of natural gas and other complementary products and services by Southern Company Gas. Revenues from sales by Southern Power to the traditional electric operating companies were $364 million, $398 million, and $435 million in 2020, 2019, and 2018, respectively. Revenues from sales of natural gas from Southern Company Gas to the traditional electric operating companies and Southern Power were immaterial and $26 million, respectively, in 2020, $14 million and $64 million, respectively, in 2019, and $32 million and $119 million, respectively, in 2018. The "All Other" column includes the Southern Company parent entity, which does not allocate operating expenses to business segments. Also, this category includes segments below the quantitative threshold for separate disclosure. These segments include providing energy solutions to electric utilities and their customers in the areas of distributed generation, energy storage and renewables, and energy efficiency, as well as investments in telecommunications and leveraged lease projects. All other inter-segment revenues are not material. Financial data for business segments and products and services for the years ended December 31, 2020, 2019, and 2018 was as follows: Electric Utilities Traditional Southern Eliminations Total Southern Company Gas All Eliminations Consolidated (in millions) 2020 Operating revenues $ 15,135 $ 1,733 $ (371) $ 16,497 $ 3,434 $ 596 $ (152) $ 20,375 Depreciation and amortization 2,447 494 — 2,941 500 77 — 3,518 Interest income 26 4 — 30 5 6 (4) 37 Earnings from equity method investments — — — — 141 12 — 153 Interest expense 825 151 — 976 231 614 — 1,821 Income taxes (benefit) 514 3 — 517 173 (297) — 393 Segment net income (loss) (a)(b)(c)(d)(e) 2,877 238 — 3,115 590 (592) 6 3,119 Goodwill — 2 — 2 5,015 263 — 5,280 Total assets 85,486 13,235 (680) 98,041 22,630 3,168 (904) 122,935 2019 Operating revenues $ 15,569 $ 1,938 $ (412) $ 17,095 $ 3,792 $ 690 $ (158) $ 21,419 Depreciation and amortization 1,993 479 — 2,472 487 79 — 3,038 Interest income 38 9 — 47 3 16 (6) 60 Earnings from equity method investments 2 3 — 5 157 — — 162 Interest expense 818 169 — 987 232 517 — 1,736 Income taxes (benefit) 764 (56) — 708 130 960 — 1,798 Segment net income (loss) (a)(f)(g)(h) 2,929 339 — 3,268 585 908 (22) 4,739 Goodwill — 2 — 2 5,015 263 — 5,280 Total assets 81,063 14,300 (713) 94,650 21,687 3,511 (1,148) 118,700 2018 Operating revenues $ 16,843 $ 2,205 $ (477) $ 18,571 $ 3,909 $ 1,213 $ (198) $ 23,495 Depreciation and amortization 2,072 493 — 2,565 500 66 — 3,131 Interest income 23 8 — 31 4 8 (5) 38 Earnings from equity method investments (1) — — (1) 148 2 (1) 148 Interest expense 852 183 — 1,035 228 580 (1) 1,842 Income taxes (benefit) 371 (164) — 207 464 (222) — 449 Segment net income (loss) (a)(b)(i)(j) 2,117 187 — 2,304 372 (453) 3 2,226 Goodwill — 2 — 2 5,015 298 — 5,315 Total assets 79,382 14,883 (306) 93,959 21,448 3,285 (1,778) 116,914 (a) Attributable to Southern Company. (b) For the traditional electric operating companies, includes pre-tax charges at Georgia Power for estimated loss on Plant Vogtle Units 3 and 4 of $325 million ($242 million after tax) in 2020 and $1.1 billion ($0.8 billion after tax) in 2018. See Note 2 under "Georgia Power – Nuclear Construction" for additional information. (c) For Southern Power, includes a $39 million pre-tax gain ($23 million gain after tax) on the sale of Plant Mankato. See Note 15 under "Southern Power" for additional information. (d) For Southern Company Gas, includes a $22 million pre-tax gain ($16 million gain after tax) on the sale of Jefferson Island. See Note 15 under "Southern Company Gas" for additional information. (e) For the "All Other" column, includes pre-tax impairment charges totaling $206 million ($105 million after tax) related to leveraged lease investments. See Note 3 under "Other Matters – Southern Company" for additional information. (f) For Southern Power, includes a $23 million pre-tax gain ($88 million gain after tax) on the sale of Plant Nacogdoches. See Note 15 under "Southern Power" for additional information. (g) For Southern Company Gas, includes pre-tax impairment charges totaling $115 million ($86 million after tax). See Notes 3 and 15 under "Other Matters – Southern Company Gas" and "Southern Company Gas – Sale of Pivotal LNG and Atlantic Coast Pipeline," respectively, for additional information. (h) For the "All Other" column, includes the pre-tax gain associated with the sale of Gulf Power of $2.6 billion ($1.4 billion after tax), the pre-tax loss, including related impairment charges, on the sales of certain PowerSecure business units totaling $58 million ($52 million after tax), and a pre-tax impairment charge of $17 million ($13 million after tax) related to a leveraged lease investment. See Notes 3 and 15 under "Other Matters – Southern Company" and "Southern Company," respectively, for additional information. (i) For Southern Power, includes pre-tax impairment charges of $156 million ($117 million after tax). See Note 15 under "Southern Power" for additional information. (j) For Southern Company Gas, includes a net gain on dispositions of $291 million ($51 million loss after tax), as well as a goodwill impairment charge of $42 million related to the sale of Pivotal Home Solutions. See Note 15 under "Southern Company Gas" for additional information. Products and Services Electric Utilities' Revenues Year Retail Wholesale Other Total (in millions) 2020 $ 13,643 $ 1,945 $ 909 $ 16,497 2019 14,084 2,152 859 17,095 2018 15,222 2,516 833 18,571 Southern Company Gas' Revenues Year Gas Gas All Other Total (in millions) 2020 $ 2,902 $ 408 $ 124 $ 3,434 2019 3,001 456 335 3,792 2018 3,155 568 186 3,909 Southern Company Gas Southern Company Gas manages its business through four reportable segments - gas distribution operations, gas pipeline investments, wholesale gas services, and gas marketing services. The non-reportable segments are combined and presented as all other. See Note 15 under "Southern Company Gas" for additional information on the disposition activities described herein. Gas distribution operations is the largest component of Southern Company Gas' business and includes natural gas local distribution utilities that construct, manage, and maintain intrastate natural gas pipelines and gas distribution facilities in four states. In July 2018, Southern Company Gas sold three of its natural gas distribution utilities, Elizabethtown Gas, Elkton Gas, and Florida City Gas. Gas pipeline investments consists of joint ventures in natural gas pipeline investments including a 50% interest in SNG, a 20% ownership interest in the PennEast Pipeline project, and a 50% joint ownership interest in the Dalton Pipeline. These natural gas pipelines enable the provision of diverse sources of natural gas supplies to the customers of Southern Company Gas. Gas pipeline investments also included a 5% ownership interest in the Atlantic Coast Pipeline construction project prior to its sale on March 24, 2020. See Notes 3, 5, and 7 for additional information. Wholesale gas services provides natural gas asset management and/or related logistics services for each of Southern Company Gas' utilities except Nicor Gas as well as for non-affiliated companies. Additionally, wholesale gas services engages in natural gas storage and gas pipeline arbitrage and related activities. Gas marketing services provides natural gas marketing to end-use customers primarily in Georgia and Illinois through SouthStar. In June 2018, Southern Company Gas sold Pivotal Home Solutions, which provided home equipment protection products and services. The all other column includes segments and subsidiaries that fall below the quantitative threshold for separate disclosure, including storage and fuels operations. The all other column included Jefferson Island though its sale on December 1, 2020, Pivotal LNG through its sale on March 24, 2020, and the investment in Triton through its sale on May 29, 2019. Financial data for business segments for the years ended December 31, 2020, 2019, and 2018 was as follows: Gas Distribution Operations (a) Gas Pipeline Investments Wholesale Gas Services (b) Gas Marketing Services (c) Total All Other (d) Eliminations Consolidated (in millions) 2020 Operating revenues $ 2,952 $ 32 $ 74 $ 408 $ 3,466 $ 36 $ (68) $ 3,434 Depreciation and amortization 442 5 1 22 470 30 — 500 Operating income (loss) 655 20 20 119 814 (7) 5 812 Earnings from equity method investments — 141 — — 141 — — 141 Interest expense 192 29 4 3 228 3 — 231 Income taxes (benefit) 114 33 3 28 178 (5) — 173 Segment net income (loss) 390 99 14 89 592 (2) — 590 Total assets at December 31, 2020 19,090 1,597 850 1,503 23,040 11,336 (11,746) 22,630 2019 Operating revenues $ 3,028 $ 32 $ 294 $ 456 $ 3,810 $ 44 $ (62) $ 3,792 Depreciation and amortization 422 5 1 26 454 33 — 487 Operating income (loss) 573 20 219 112 924 (154) — 770 Earnings from equity method investments — 162 — — 162 (5) — 157 Interest expense 187 30 5 3 225 7 — 232 Income taxes (benefit) 63 58 52 27 200 (70) — 130 Segment net income (loss) 337 94 163 83 677 (92) — 585 Total assets at December 31, 2019 18,204 1,678 850 1,496 22,228 10,759 (11,300) 21,687 2018 Operating revenues $ 3,186 $ 32 $ 144 $ 568 $ 3,930 $ 55 $ (76) $ 3,909 Depreciation and amortization 409 5 2 37 453 47 — 500 Operating income (loss) 904 20 70 19 1,013 (98) — 915 Earnings from equity method investments — 145 — — 145 3 — 148 Interest expense 178 34 9 6 227 1 — 228 Income taxes (benefit) 409 28 4 54 495 (31) — 464 Segment net income (loss) 334 103 38 (40) 435 (63) — 372 Total assets at December 31, 2018 17,266 1,763 1,302 1,587 21,918 11,112 (11,582) 21,448 (a) Operating revenues for the three gas distribution operations dispositions were $244 million for 2018. Segment net income for gas distribution operations includes a gain on dispositions of $324 million ($16 million after tax) in 2018. (b) The revenues for wholesale gas services are netted with costs associated with its energy and risk management activities. A reconciliation of operating revenues and intercompany revenues is shown in the following table. Third Party Gross Revenues Intercompany Revenues Total Gross Revenues Less Gross Gas Costs Operating Revenues (in millions) 2020 $ 4,544 $ 115 $ 4,659 $ 4,585 $ 74 2019 5,703 275 5,978 5,684 294 2018 6,955 451 7,406 7,262 144 (c) Operating revenues for the gas marketing services disposition were $55 million in 2018. Segment net income for gas marketing services includes a loss on disposition of $33 million ($67 million loss after tax) and a goodwill impairment charge of $42 million in 2018 recorded in contemplation of the sale of Pivotal Home Solutions. (d) Segment net income (loss) for the "All Other" column include s a $22 million pre-tax gain ($16 million g ain after tax) on the sale of Jefferson Island in 2020 and pre-tax impairment charges totaling $115 million ($86 million after tax) in 2019. See Note 3 under "Other Matters – Southern Company Gas" for additional information. |
VALUATION AND QUALIFYING ACCOUN
VALUATION AND QUALIFYING ACCOUNTS | 12 Months Ended |
Dec. 31, 2020 | |
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract] | |
VALUATION AND QUALIFYING ACCOUNTS | THE SOUTHERN COMPANY AND SUBSIDIARY COMPANIES SCHEDULE II — VALUATION AND QUALIFYING ACCOUNTS FOR THE YEARS ENDED DECEMBER 31, 2020, 2019, AND 2018 (Stated in Millions of Dollars) Additions Description Balance at Beginning of Period Charged to Income Charged to Other Accounts (a) Deductions Reclassified to Held for Sale (b) Balance at End of Period Provision for uncollectible accounts (c) 2020 $ 49 $ 78 $ 27 $ 36 $ — $ 118 2019 50 68 — 69 — 49 2018 44 69 (1) 61 1 50 Tax valuation allowance (net state) (d) 2020 $ 113 $ — $ — $ 1 $ — $ 112 2019 100 13 — — — 113 2018 148 (38) — 10 — 100 (a) During 2020, Georgia Power recorded $23 million of expected bad debt related to the COVID-19 pandemic to a regulatory asset in accordance with orders from the Georgia PSC. See Note 2 to the financial statements under "Georgia Power – Deferral of Incremental COVID-19 Costs" in Item 8 herein for additional information. (b) Represents provision for uncollectible accounts at Gulf Power reclassified as held for sale during 2018. See Note 15 to the financial statements under "Southern Company" in Item 8 herein for additional information. (c) Deductions represent write-offs of accounts considered to be uncollectible, less recoveries of amounts previously written off. (d) In 2018, as a result of higher projected state taxable income, Mississippi Power reduced a valuation allowance associated with a State of Mississippi net operating loss carryforward expected to expire prior to being fully utilized. In 2018, Georgia Power established a valuation allowance for certain Georgia state tax credits expected to expire prior to being fully utilized, as a result of lower projected state taxable income. See Note 10 to the financial statements in Item 8 herein for additional information. ALABAMA POWER COMPANY SCHEDULE II — VALUATION AND QUALIFYING ACCOUNTS FOR THE YEARS ENDED DECEMBER 31, 2020, 2019, AND 2018 (Stated in Millions of Dollars) Additions Description Balance at Beginning Charged to Charged to Other Accounts Deductions (*) Balance at Provision for uncollectible accounts 2020 $ 22 $ 25 $ — $ 4 $ 43 2019 10 24 — 12 22 2018 9 13 — 12 10 (*) Deductions represent write-offs of accounts considered to be uncollectible, less recoveries of amounts previously written off. GEORGIA POWER COMPANY SCHEDULE II — VALUATION AND QUALIFYING ACCOUNTS FOR THE YEARS ENDED DECEMBER 31, 2020, 2019, AND 2018 (Stated in Millions of Dollars) Additions Description Balance at Beginning Charged to Charged to Other Accounts (a) Deductions Balance at End of Period Provision for uncollectible accounts (b) 2020 $ 2 $ 14 $ 23 $ 13 $ 26 2019 2 13 — 13 2 2018 3 11 — 12 2 Tax valuation allowance (net state) (c) 2020 $ 28 $ — $ — $ — $ 28 2019 33 (5) — — 28 2018 — 39 — 6 33 (a) During 2020, Georgia Power recorded $23 million of expected bad debt related to the COVID-19 pandemic to a regulatory asset in accordance with orders from the Georgia PSC. See Note 2 to the financial statements under "Georgia Power – Deferral of Incremental COVID-19 Costs" in Item 8 herein for additional information. (b) Deductions represent write-offs of accounts considered to be uncollectible, less recoveries of amounts previously written off. (c) In 2018, Georgia Power established a valuation allowance for certain Georgia state tax credits expected to expire prior to being fully utilized, which was reduced in 2019 as a result of higher projected state taxable income. See Note 10 to the financial statements in Item 8 herein for additional information. MISSISSIPPI POWER COMPANY SCHEDULE II — VALUATION AND QUALIFYING ACCOUNTS FOR THE YEARS ENDED DECEMBER 31, 2020, 2019, AND 2018 (Stated in Millions of Dollars) Additions Description Balance at Beginning Charged to Charged to Other Deductions Balance at End of Period Provision for uncollectible accounts (a) 2020 $ 1 $ 1 $ — $ 1 $ 1 2019 1 2 — 2 1 2018 1 1 — 1 1 Tax valuation allowance (net state) (b) 2020 $ 32 $ — $ — $ — $ 32 2019 32 — — — 32 2018 124 (92) — — 32 (a) Deductions represent write-offs of accounts considered to be uncollectible, less recoveries of amounts previously written off. (b) In 2018, as a result of higher projected state taxable income, Mississippi Power reduced a valuation allowance associated with a State of Mississippi net operating loss carryforward expected to expire prior to being fully utilized. See Note 10 to the financial statements in Item 8 herein for additional information. SOUTHERN POWER COMPANY AND SUBSIDIARY COMPANIES SCHEDULE II — VALUATION AND QUALIFYING ACCOUNTS FOR THE YEARS ENDED DECEMBER 31, 2020, 2019, AND 2018 (Stated in Millions of Dollars) Additions Description Balance at Beginning Charged to Charged to Other Deductions Balance at End of Period Tax valuation allowance (net state) 2020 $ 29 $ (1) $ — $ 1 $ 27 2019 22 7 — — 29 2018 10 12 — — 22 SOUTHERN COMPANY GAS AND SUBSIDIARY COMPANIES SCHEDULE II — VALUATION AND QUALIFYING ACCOUNTS FOR THE YEARS ENDED DECEMBER 31, 2020, 2019, AND 2018 (Stated in Millions of Dollars) Additions Description Balance at Beginning Charged to Charged to Other Accounts Deductions Balance at Provision for uncollectible accounts (a) 2020 $ 18 $ 35 $ 4 $ 17 $ 40 2019 30 29 — 41 18 2018 28 33 (1) 30 30 Tax valuation allowance (net state) (b) 2020 $ 4 $ — $ — $ — $ 4 2019 12 (8) — — 4 2018 11 1 — — 12 (a) Deductions represent write-offs of accounts considered to be uncollectible, less recoveries of amounts previously written off. (b) In 2019, Southern Company Gas reversed a $13 million valuation allowance for a federal deferred tax asset in connection with the sale of Triton. Additionally, in 2019, a $5 million valuation allowance was established for a state net operating loss carryforward expected to expire prior to being fully utilized. See Note 10 to the financial statements and Note 15 to the financial statements under "Southern Company Gas" in Item 8 herein for additional information. |
SUMMARY OF SIGNIFICANT ACCOUN_2
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) | 12 Months Ended |
Dec. 31, 2020 | |
Accounting Policies [Abstract] | |
General | General Southern Company is the parent company of three traditional electric operating companies, as well as Southern Power, Southern Company Gas, SCS, Southern Linc, Southern Holdings, Southern Nuclear, PowerSecure, and other direct and indirect subsidiaries. The traditional electric operating companies – Alabama Power, Georgia Power, and Mississippi Power – are vertically integrated utilities providing electric service in three Southeastern states. In January 2019, Southern Company completed the sale of Gulf Power (another traditional electric operating company through December 31, 2018) to NextEra Energy. Southern Power develops, constructs, acquires, owns, and manages power generation assets, including renewable energy and battery energy storage projects, and sells electricity at market-based rates in the wholesale market. Southern Company Gas distributes natural gas through natural gas distribution utilities, including Nicor Gas (Illinois), Atlanta Gas Light (Georgia), Virginia Natural Gas, and Chattanooga Gas (Tennessee). In 2018, Southern Company Gas sold its other natural gas utilities – Elizabethtown Gas (New Jersey), Florida City Gas, and Elkton Gas (Maryland). Southern Company Gas is also involved in several other complementary businesses including gas pipeline investments, wholesale gas services, and gas marketing services. SCS, the system service company, provides, at cost, specialized services to Southern Company and its subsidiary companies. Southern Linc provides digital wireless communications for use by Southern Company and its subsidiary companies and also markets these services to the public and provides fiber optics services within the Southeast. Southern Holdings is an intermediate holding company subsidiary, primarily for Southern Company's leveraged lease and other investments. Southern Nuclear operates and provides services to the Southern Company system's nuclear power plants, including Alabama Power's Plant Farley and Georgia Power's Plant Hatch and Plant Vogtle Units 1 and 2, and is currently managing construction and start-up of Plant Vogtle Units 3 and 4, which are co-owned by Georgia Power. PowerSecure provides energy solutions to electric utilities and their customers in the areas of distributed generation, energy storage and renewables, and energy efficiency. See Note 15 for information regarding disposition activities, including Southern Company's sale of Gulf Power. The Registrants' financial statements reflect investments in subsidiaries on a consolidated basis. Intercompany transactions have been eliminated in consolidation. The equity method is used for investments in entities in which a Registrant has significant influence but does not have control and for VIEs where a Registrant has an equity investment but is not the primary beneficiary. Southern Power has controlling ownership in certain legal entities for which the contractual provisions represent profit-sharing arrangements because the allocations of cash distributions and tax benefits are not based on fixed ownership percentages. For these arrangements, the noncontrolling interest is accounted for under a balance sheet approach utilizing the HLBV method. The HLBV method calculates each partner's share of income based on the change in net equity the partner can legally claim in a HLBV at the end of the period compared to the beginning of the period. See "Variable Interest Entities" herein and Note 7 for additional information. The traditional electric operating companies, Southern Power, certain subsidiaries of Southern Company Gas, and certain other subsidiaries are subject to regulation by the FERC, and the traditional electric operating companies and the natural gas distribution utilities are also subject to regulation by their respective state PSCs or other applicable state regulatory agencies. As such, the respective financial statements of the applicable Registrants reflect the effects of rate regulation in accordance with GAAP and comply with the accounting policies and practices prescribed by relevant state PSCs or other applicable state regulatory agencies. The preparation of financial statements in conformity with GAAP requires the use of estimates, and the actual results may differ from those estimates. Certain prior years' data presented in the financial statements have been reclassified to conform to the current year presentation. These reclassifications had no impact on the Registrants' results of operations, financial position, or cash flows. |
Recently Adopted Accounting Standards | Recently Adopted Accounting Standards Effective January 1, 2019, the Registrants adopted ASU No. 2016-02, Leases (Topic 842) (ASU 2016-02). ASU 2016-02 required lessees to recognize on the balance sheet a lease liability and a right-of-use asset for all leases. ASU 2016-02 also changed the recognition, measurement, and presentation of expense associated with leases and provided clarification regarding the identification of certain components of contracts that would represent a lease. Lessor accounting was relatively unchanged and there was no change to the accounting for existing leveraged leases. See Note 9 for additional information and related disclosures. |
Affiliate Transactions | Affiliate TransactionsThe traditional electric operating companies, Southern Power, and Southern Company Gas have agreements with SCS under which certain of the following services are rendered to them at direct or allocated cost: general executive and advisory, general and design engineering, operations, purchasing, accounting, finance, treasury, legal, tax, information technology, marketing, auditing, insurance and pension administration, human resources, systems and procedures, digital wireless communications, cellular tower space, and other services with respect to business and operations, construction management, and Southern Company power pool transactions. These costs are primarily included in other operations and maintenance expenses or capitalized to property, plant, and equipment. |
Regulatory Assets and Liabilities | Regulatory Assets and Liabilities The traditional electric operating companies and the natural gas distribution utilities are subject to accounting requirements for the effects of rate regulation. Regulatory assets represent probable future revenues associated with certain costs that are expected to be recovered from customers through the ratemaking process. Regulatory liabilities represent costs recovered that are expected to be incurred in the future or probable future reductions in revenues associated with amounts that are expected to be credited to customers through the ratemaking process. In the event that a portion of a traditional electric operating company's or a natural gas distribution utility's operations is no longer subject to applicable accounting rules for rate regulation, such company would be required to write off to income or reclassify to AOCI related regulatory assets and liabilities that are not specifically recoverable through regulated rates. In addition, the traditional electric operating company or the natural gas distribution utility would be required to determine if any impairment to other assets, including plant, exists and write down the assets, if impaired, to their fair values. All regulatory assets and liabilities are to be reflected in rates. See Note 2 for additional information including details of regulatory assets and liabilities reflected in the balance sheets for Southern Company, the traditional electric operating companies, and Southern Company Gas. |
Revenues | Revenues The Registrants generate revenues from a variety of sources which are accounted for under various revenue accounting guidance, including revenue from contracts with customers, lease, derivative, and regulatory accounting. See Notes 4, 9, and 14 for additional information. Traditional Electric Operating Companies The majority of the revenues of the traditional electric operating companies are generated from contracts with retail electric customers. These revenues, generated from the integrated service to deliver electricity when and if called upon by the customer, are recognized as a single performance obligation satisfied over time, at a tariff rate, and as electricity is delivered to the customer during the month. Unbilled revenues related to retail sales are accrued at the end of each fiscal period. Retail rates may include provisions to adjust revenues for fluctuations in fuel costs, fuel hedging, the energy component of purchased power costs, and certain other costs. Revenues are adjusted for differences between these actual costs and amounts billed in current regulated rates. Under or over recovered regulatory clause revenues are recorded in the balance sheets and are recovered from or returned to customers, respectively, through adjustments to the billing factors. See Note 2 for additional information regarding regulatory matters of the traditional electric operating companies. Wholesale capacity revenues from PPAs are recognized in amounts billable under the contract terms. Energy and other revenues are generally recognized as services are provided. The contracts for capacity and energy in a wholesale PPA have multiple performance obligations where the contract's total transaction price is allocated to each performance obligation based on the standalone selling price. The standalone selling price is primarily determined by the price charged to customers for the specific goods or services transferred with the performance obligations. Generally, the traditional electric operating companies recognize revenue as the performance obligations are satisfied over time as electricity is delivered to the customer or as generation capacity is available to the customer. For both retail and wholesale revenues, the traditional electric operating companies have elected to recognize revenue for their sales of electricity and capacity using the invoice practical expedient as they generally have a right to consideration in an amount that corresponds directly with the value to the customer of the performance completed to date and that may be invoiced. Payment for goods and services rendered is typically due in the subsequent month following satisfaction of the Registrants' performance obligation. Southern Power Southern Power sells capacity and energy at rates specified under contractual terms in long-term PPAs. These PPAs are accounted for as operating leases, non-derivatives, or normal sale derivatives. Capacity revenues from PPAs classified as operating leases are recognized on a straight-line basis over the term of the agreement. Energy revenues are recognized in the period the energy is delivered. Southern Power's non-lease contracts commonly include capacity and energy which are considered separate performance obligations. In these contracts, the total transaction price is allocated to each performance obligation based on the standalone selling price. The standalone selling price is primarily determined by the price charged to customers for the specific goods or services transferred with the performance obligations. Generally, Southern Power recognizes revenue as the performance obligations are satisfied over time, as electricity is delivered to the customer or as generation capacity is made available to the customer. Southern Power generally has a right to consideration in an amount that corresponds directly with the value to the customer of the performance completed to date and may recognize revenue in the amount to which the entity has a right to invoice. Payment for goods and services rendered is typically due in the subsequent month following satisfaction of Southern Power's performance obligation. When multiple contracts exist with the same counterparty, the revenues from each contract are accounted for as separate arrangements. Southern Power may also enter into contracts to sell short-term capacity in the wholesale electricity markets. These sales are generally classified as mark-to-market derivatives and net unrealized gains and losses on such contracts are recorded in wholesale revenues. See Note 14 and "Financial Instruments" herein for additional information. Southern Company Gas Gas Distribution Operations Southern Company Gas records revenues when goods or services are provided to customers. Those revenues are based on rates approved by the state regulatory agencies of the natural gas distribution utilities. Atlanta Gas Light operates in a deregulated natural gas market wher eby M arketers, rather than a traditional utility, sell natural gas to end-use customers in Georgia and handle customer billing functions. As required by the Georgia PSC, Atlanta Gas Light bills Marketers in equal monthly installments for each residential, commercial, and industrial end-use customer's distribution costs as well as for capacity costs utilizing a seasonal rate design for the calculation of each residential end-use customer's annual straight-fixed-variable charge, which reflects the historic volumetric usage pattern for the entire residential class. The majority of the revenues of Southern Company Gas are generated from contracts with natural gas distribution customers. Revenues from this integrated service to deliver gas when and if called upon by the customer are recognized as a single performance obligation satisfied over time and are recognized at a tariff rate as gas is delivered to the customer during the month. The standalone selling price is primarily determined by the price charged to customers for the specific goods or services transferred with the performance obligations. Generally, Southern Company Gas recognizes revenue as the performance obligations are satisfied over time as natural gas is delivered to the customer. The performance obligations related to wholesale gas services are satisfied, and revenue is recognized, at a point in time when natural gas is delivered to the customer. Southern Company Gas has elected to recognize revenue for sales of gas using the invoice practical expedient as it generally has a right to consideration in an amount that corresponds directly with the value to the customer of the performance completed to date and that may be invoiced. Payment for goods and services rendered is typically due in the subsequent month following satisfaction of Southern Company Gas' performance obligation. With the exception of Atlanta Gas Light, the natural gas distribution utilities have rate structures that include volumetric rate designs that allow the opportunity to recover certain costs based on gas usage. Revenues from sales and transportation services are recognized in the same period in which the related volumes are delivered to customers. Revenues from residential and certain commercial and industrial customers are recognized on the basis of scheduled meter readings. Additionally, unbilled revenues are recognized for estimated deliveries of gas not yet billed to these customers, from the last bill date to the end of the accounting period. For other commercial and industrial customers and for all wholesale customers, revenues are based on actual deliveries through the end of the period. The tariffs for several of the natural gas distribution utilities include provisions which allow for the recognition of certain revenues prior to the time such revenues are billed to customers. These provisions are referred to as alternative revenue programs and provide for the recognition of certain revenues prior to billing, as long as the amounts recognized will be collected from customers within 24 months of recognition. These programs are as follows: • Weather normalization adjustments – reduce customer bills when winter weather is colder than normal and increase customer bills when weather is warmer than normal and are included in the tariffs for Virginia Natural Gas, Chattanooga Gas, and, prior to its sale, Elizabethtown Gas; • Revenue normalization mechanisms – mitigate the impact of conservation and declining customer usage and are contained in the tariffs for Virginia Natural Gas, Chattanooga Gas, Nicor Gas (effective November 1, 2019), and, prior to its sale, Elkton Gas; and • Revenue true-up adjustment – included within the provisions of the GRAM program in which Atlanta Gas Light participates as a short-term alternative to formal rate case filings, the revenue true-up feature provides for a positive (or negative) adjustment to record revenue in the amount of any variance to budgeted revenues, which are submitted and approved annually as a requirement of GRAM. Such adjustments are reflected in customer billings in a subsequent program year. Wholesale Gas Services Southern Company Gas nets revenues from energy and risk management activities with the associated costs. Profits from sales between segments are eliminated and are recognized as goods or services sold to end-use customers. Southern Company Gas records transactions that qualify as derivatives at fair value with changes in fair value recognized in earnings in the period of change and characterized as unrealized gains or losses. Gains and losses on derivatives held for energy trading purposes are presented on a net basis in revenue. Gas Marketing Services Southern Company Gas recognizes revenues from natural gas sales and transportation services in the same period in which the related volumes are delivered to customers and recognizes sales revenues from residential and certain commercial and industrial customers on the basis of scheduled meter readings. Southern Company Gas also recognizes unbilled revenues for estimated deliveries of gas not yet billed to these customers from the most recent meter reading date to the end of the accounting period. For other commercial and industrial customers and for all wholesale customers, revenues are based on actual deliveries during the period. Southern Company Gas recognizes revenues on 12-month utility-bill management contracts as the lesser of cumulative earned or cumulative billed amounts. Concentration of Revenue Southern Company, Alabama Power, Georgia Power, Mississippi Power (with the exception of its full requirements cost-based MRA electric tariffs described below), and Southern Company Gas each have a diversified base of customers and no single customer or industry comprises 10% or more of each company's revenues. Mississippi Power provides service under long-term contracts with rural electric cooperative associations and a municipality located in southeastern Mississippi under full requirements cost-based MRA electric tariffs, which are subject to regulation by the FERC. The contracts with these wholesale customers represent ed 15.3% of Mississippi Power 's total operating revenues in 2020 and are generally subject to 10 -year rolling c ancellation notices. Historically, these wholesale customers have acted as a group and any changes in contractual relationships for one customer are likely to be followed by the other wholesale customers. |
Concentration of Credit Risk | Concentration of Credit Risk Southern Company Gas' wholesale gas services business has a concentration of credit risk for services it provides to its counterparties. This credit risk is generally concentrated in 20 of its counterparties and is measured by 30-day receivable exposure plus forward exposure. Counterparty credit risk is evaluated using a S&P equivalent credit rating, which is determined by a process of converting the lower of the S&P or Moody's rating to an internal rating ranging from 9 to 1, with 9 being equivalent to AAA/Aaa by S&P and Moody's, respectively, and 1 being equivalent to D/Default by S&P and Moody's, respectively. A counterparty that does not have an external rating is assigned an internal rating based on the strength of its financial ratios. As of December 31, 2020, the top 20 counterparties represented 58%, or $234 million , of the total counterparty exposure and had a weighted average S&P equivalent rating of A-. Concentration of credit risk occurs at Atlanta Gas Light for amounts billed for services and other costs to its customers, which consist of 16 Marketers in Georgia (including SouthStar). The credit risk exposure to the Marketers varies seasonally, with the lowest exposure in the non-peak summer months and the highest exposure in the peak winter months. Marketers are responsible for the retail sale of natural gas to end-use customers in Georgia. The functions of the retail sale of gas include the purchase and sale of natural gas, customer service, billings, and collections. The provisions of Atlanta Gas Light's tariff allow Atlanta Gas Light to obtain credit security support in an amount equal to a minimum of two times a Marketer's highest month's estimated bill from Atlanta Gas Light. |
Fuel Costs | Fuel Costs Fuel costs for the traditional electric operating companies and Southern Power are expensed as the fuel is used. Fuel expense generally includes fuel transportation costs and the cost of purchased emissions allowances as they are used. For Alabama Power and Georgia Power, fuel expense also includes the amortization of the cost of nuclear fuel. For the traditional electric operating companies, fuel costs also include gains and/or losses from fuel-hedging programs as approved by their respective state PSCs. |
Cost of Natural Gas | Cost of Natural Gas Excluding Atlanta Gas Light, which does not sell natural gas to end-use customers, Southern Company Gas charges its utility customers for natural gas consumed using natural gas cost recovery mechanisms set by the applicable state regulatory agencies. Under these mechanisms, all prudently-incurred natural gas costs are passed through to customers without markup, subject to regulatory review. Southern Company Gas defers or accrues the difference between the actual cost of natural gas and the amount of commodity revenue earned in a given period such that no operating income is recognized related to these costs. The deferred or accrued amount is either billed or refunded to customers prospectively through adjustments to the commodity rate. Deferred and accrued natural gas costs are included in the balance sheets as regulatory assets and regulatory liabilities, respectively. Southern Company Gas' gas marketing services' customers are charged for actual or estimated natural gas consumed. Within cost of natural gas, Southern Company Gas also includes costs of lost and unaccounted for gas, adjustments to reduce the value of inventories to market value, and gains and losses associated with certain derivatives. |
Income Taxes and Other Taxes | Income Taxes The Registrants use the liability method of accounting for deferred income taxes and provide deferred income taxes for all significant income tax temporary differences. In accordance with regulatory requirements, deferred federal ITCs for the traditional electric operating companies are deferred and amortized over the average life of the related property, with such amortization normally applied as a credit to reduce depreciation and amortization in the statements of income. Southern Power's and the natural gas distribution utilities' deferred federal ITCs, as well as certain state ITCs for Nicor Gas, are deferred and amortized to income tax expense over the life of the respective asset. Under current tax law, certain projects at Southern Power related to the construction of renewable facilities are eligible for federal ITCs. Southern Power estimates eligible costs which, as they relate to acquisitions, may not be finalized until the allocation of the purchase price to assets has been finalized. Southern Power applies the deferred method to ITCs, whereby the ITCs are recorded as a deferred credit and amortized to income tax expense over the life of the respective asset. Furthermore, the tax basis of the asset is reduced by 50% of the ITCs received, resulting in a net deferred tax asset. Southern Power has elected to recognize the tax benefit of this basis difference as a reduction to income tax expense in the year in which the plant reaches commercial operation. State ITCs are recognized as an income tax benefit in the period in which the credits are generated. In addition, certain projects are eligible for federal and state PTCs, which are recognized as an income tax benefit based on KWH production. Federal ITCs and PTCs, as well as state ITCs and other state tax credits available to reduce income taxes payable, were not fully utilized in 2020 and will be carried forward and utilized in future years. In addition, Southern Company is expected to have various state net operating loss (NOL) carryforwards for certain of its subsidiaries, including Mississippi Power and Southern Power, which would result in income tax benefits in the future, if utilized. See Note 10 under "Current and Deferred Income Taxes – Tax Credit Carryforwards" and " – Net Operating Loss Carryforwards" for additional information. The Registrants recognize tax positions that are "more likely than not" of being sustained upon examination by the appropriate taxing authorities. See Note 10 under "Unrecognized Tax Benefits" for additional information. Other Taxes Taxes imposed on and collected from customers on behalf of governmental agencies are presented net on the Registrants' statements of income and are excluded from the transaction price in determining the revenue related to contracts with a customer. |
Allowance for Funds Used During Construction and Interest Capitalized | Allowance for Funds Used During Construction and Interest Capitalized The traditional electric operating companies and the natural gas distribution utilities record AFUDC, which represents the estimated debt and equity costs of capital funds that are necessary to finance the construction of new regulated facilities. While cash is not realized currently, AFUDC increases the revenue requirement and is recovered over the service life of the asset through a higher rate base and higher depreciation. The equity component of AFUDC is not taxable. Interest related to financing the construction of new facilities at Southern Power and new facilities not included in the traditional electric operating companies' and Southern Company Gas' regulated rates is capitalized in accordance with standard interest capitalization requirements. |
Impairment of Long-Lived Assets | Impairment of Long-Lived Assets The Registrants evaluate long-lived assets and finite-lived intangible assets for impairment when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable. The determination of whether an impairment has occurred is based on either a specific regulatory disallowance, a sales transaction price that is less than the asset group's carrying value, or an estimate of undiscounted future cash flows attributable to the asset group, as compared with the carrying value of the assets. If an impairment has occurred, the amount of the impairment recognized is determined by either the amount of regulatory disallowance or by estimating the fair value of the assets and recording a loss if the carrying value is greater than the |
Goodwill and Other Intangible Assets and Liabilities | Goodwill and Other Intangible Assets and Liabilities Southern Power's intangible assets consist primarily of certain PPAs acquired, which are amortized over the term of the respective PPA. Southern Company Gas' goodwill and other intangible assets and liabilities primarily relate to its 2016 acquisition by Southern Company. In addition to these items, Southern Company's goodwill and other intangible assets also relate to its 2016 acquisition of PowerSecure. |
Acquisition Accounting | Acquisition Accounting At the time of an acquisition, management will assess whether acquired assets and activities meet the definition of a business. For acquisitions that meet the definition of a business, operating results from the date of acquisition are included in the acquiring entity's financial statements. The purchase price, including any contingent consideration, is allocated based on the fair value of the identifiable assets acquired and liabilities assumed (including any intangible assets). Assets acquired that do not meet the definition of a business are accounted for as an asset acquisition. The purchase price of each asset acquisition is allocated based on the relative fair value of assets acquired. Determining the fair value of assets acquired and liabilities assumed requires management judgment and management may engage independent valuation experts to assist in this process. Fair values are determined by using market participant assumptions and typically include the timing and amounts of future cash flows, incurred construction costs, the nature of acquired contracts, discount rates, power market prices, and expected asset lives. Any due diligence or transition costs incurred for potential or successful acquisitions are expensed as incurred. |
Development Costs | Development Costs For Southern Power, development costs are capitalized once a project is probable of completion, primarily based on a review of its economics and operational feasibility, as well as the status of power off-take agreements and regulatory approvals, if applicable. Southern Power's capitalized development costs are included in CWIP on the balance sheets. All of Southern Power's development costs incurred prior to the determination that a project is probable of completion are expensed as incurred and included in other operations and maintenance expense in the statements of income. If it is determined that a project is no longer probable of completion, any of Southern Power's capitalized development costs are expensed and included in other operations and maintenance expense in the statements of income. |
Long-Term Service Agreements | Long-Term Service Agreements The traditional electric operating companies and Southern Power have entered into LTSAs for the purpose of securing maintenance support for certain of their generating facilities. The LTSAs cover all planned inspections on the covered equipment, which generally includes the cost of all labor and materials. The LTSAs also obligate the counterparties to cover the costs of unplanned maintenance on the covered equipment subject to limits and scope specified in each contract. Payments made under the LTSAs for the performance of any planned inspections or unplanned capital maintenance are recorded in the statements of cash flows as investing activities. Receipts of major parts into materials and supplies inventory prior to planned inspections are treated as noncash transactions in the statements of cash flows. Any payments made prior to the work being performed are recorded as prepayments in other current assets and noncurrent assets on the balance sheets. At the time work is performed, an appropriate amount is accrued for future payments or transferred from the prepayment and recorded as property, plant, and equipment or expensed. |
Transmission Receivables/Prepayments | Transmission Receivables/Prepayments As a result of Southern Power's acquisition and construction of generating facilities, Southern Power has transmission receivables and/or prepayments representing the portion of interconnection network and transmission upgrades that will be reimbursed to Southern Power. Upon completion of the related project, transmission costs are generally reimbursed by the interconnection provider within a five-year period and the receivable/prepayments are reduced as payments or services are received. |
Cash and Cash Equivalents | Cash and Cash Equivalents For purposes of the financial statements, temporary cash investments are considered cash equivalents. Temporary cash investments are securities with original maturities of 90 days or less. |
Restricted Cash | Restricted Cash At December 31, 2020 and 2019, Southern Company Gas had $2 million and $3 million, respectively, of restricted cash held as collateral for workers' compensation, life insurance, and long-term disability insurance, which is included in cash, cash equivalents, and restricted cash on the statements of cash flows. |
Storm Damage Reserves | Storm Damage ReservesEach traditional electric operating company maintains a reserve to cover or is allowed to defer and recover the cost of damages from major storms to its transmission and distribution lines and, for Mississippi Power, the cost of uninsured damages to its generation facilities and other property. |
Leveraged Leases | Leveraged Leases At December 31, 2020 and 2019, a subsidiary of Southern Holdings had four leveraged lease agreements, with original terms ranging up to 45 years, which relate to energy generation, distribution, and transportation assets, including two international projects. Southern Company receives federal income tax deductions for depreciation and amortization, as well as interest on long-term debt related to these investments. Southern Company reviews all important lease assumptions at least annually, or more frequently if events or changes in circumstances indicate that a change in assumptions has occurred or may occur. These assumptions include the effective tax rate, the residual value, the credit quality of the lessees, and the timing of expected tax cash flows. See Notes 3 and 15 under "Other Matters – Southern Company" and "Southern Company," respectively, for additional information on the leveraged lease investments, including impairment charges and completed and planned sales. |
Materials and Supplies | Materials and Supplies Materials and supplies for the traditional electric operating companies generally includes the average cost of transmission, distribution, and generating plant materials. Materials and supplies for Southern Company Gas generally includes propane gas inventory, fleet fuel, and other materials and supplies. Materials and supplies for Southern Power generally includes the average cost of generating plant materials. Materials are recorded to inventory when purchased and then expensed or capitalized to property, plant, and equipment, as appropriate, at weighted average cost when installed. In addition, certain major parts are recorded as inventory when acquired and then capitalized at cost when installed to property, plant, and equipment. |
Fuel Inventory | Fuel Inventory Fuel inventory for the traditional electric operating companies includes the average cost of coal, natural gas, oil, transportation, and emissions allowances. Fuel inventory for Southern Power, which is included in other current assets, includes the average cost of oil, natural gas, and emissions allowances. Fuel is recorded to inventory when purchased and then expensed, at weighted average cost, as used. Emissions allowances granted by the EPA are included in inventory at zero cost. The traditional electric operating companies recover fuel expense through fuel cost recovery rates approved by each state PSC or, for wholesale rates, the FERC. |
Natural Gas for Sale | Natural Gas for Sale With the exception of Nicor Gas, the natural gas distribution utilities record natural gas inventories on a WACOG basis. In Georgia's deregulated, competitive environment, Marketers sell natural gas to firm end-use customers at market-based prices. On a monthly basis, Atlanta Gas Light assigns to Marketers the majority of the pipeline storage services that it has under contract, along with a corresponding amount of inventory. Atlanta Gas Light retains and manages a portion of its pipeline storage assets and related natural gas inventories for system balancing and to serve system demand. Nicor Gas' natural gas inventory is carried at cost on a LIFO basis. Inventory decrements occurring during the year that are restored prior to year end are charged to cost of natural gas at the estimated annual replacement cost. Inventory decrements that are not restored prior to year end are charged to cost of natural gas at the actual LIFO cost of the inventory layers liquidated. The cost of natural gas, including inventory costs, is recovered from customers under a purchased gas recovery mechanism adjusted for differences between actual costs and amounts billed; therefore, LIFO liquidations have no impact on Southern Company's or Southern Company Gas' net income. At December 31, 2020, the Nicor Gas LIFO inventory balance was $178 million. Based on the average cost of gas purchased in December 2020, the estimated replacement cost of Nicor Gas' inventory at December 31, 2020 was $259 million. |
Energy Marketing Receivables and Payables | Energy Marketing Receivables and Payables Southern Company Gas' wholesale gas services provides services to retail gas marketers, wholesale gas marketers, utility companies, and industrial customers. These counterparties utilize netting agreements that enable wholesale gas services to net receivables and payables by counterparty upon settlement. Southern Company Gas' wholesale gas services also nets across product lines and against cash collateral, provided the netting and cash collateral agreements include such provisions. While the amounts due from, or owed to, wholesale gas services' counterparties are settled net, they are recorded on a gross basis in the balance sheets as energy marketing receivables and energy marketing payables. Southern Company Gas' wholesale gas services has trade and credit contracts that contain minimum credit rating requirements. These credit rating requirements typically give counterparties the right to suspend or terminate credit if Southern Company Gas' credit ratings are downgraded to non-investment grade status. Under such circumstances, Southern Company Gas' wholesale gas services would need to post collateral to continue transacting business with some of its counterparties. As of December 31, 2020 and 2019, the required collateral in the event of a credit rating downgrade was $5 million and $11 million, respectively. Southern Company Gas' wholesale gas services uses established credit policies to determine and monitor the creditworthiness of counterparties, including requirements to post collateral or other credit security, as well as the quality of pledged collateral. Collateral or credit security is most often in the form of cash or letters of credit from an investment-grade financial institution, but may also include cash or U.S. government securities held by a trustee. When more than one derivative transaction with the same counterparty is outstanding and a legally enforceable netting agreement exists with that counterparty, the "net" mark-to-market exposure represents a reasonable measure of Southern Company Gas' credit risk with that counterparty. Southern Company Gas' wholesale gas services also uses other netting agreements with certain counterparties with whom it conducts significant transactions. |
Provision for Uncollectible Accounts | Provision for Uncollectible Accounts The customers of the traditional electric operating companies and the natural gas distribution utilities are billed monthly. For the majority of receivables, a provision for uncollectible accounts is established based on historical collection experience and other factors. For the remaining receivables, if the company is aware of a specific customer's inability to pay, a provision for uncollectible accounts is recorded to reduce the receivable balance to the amount reasonably expected to be collected. If circumstances change, the estimate of the recoverability of accounts receivable could change as well. Circumstances that could affect this estimate include, but are not limited to, customer credit issues, customer deposits, and general economic conditions. Customers' accounts are written off once they are deemed to be uncollectible. For all periods presented, uncollectible accounts averaged less than 1% of revenues for each Registrant. Credit risk exposure at Nicor Gas is mitigated by a bad debt rider approved by the Illinois Commission. The bad debt rider provides for the recovery from (or refund to) customers of the difference between Nicor Gas' actual bad debt experience on an annual basis and the benchmark bad debt expense used to establish its base rates for the respective year. |
Financial Instruments | Financial Instruments The traditional electric operating companies and Southern Power use derivative financial instruments to limit exposure to fluctuations in interest rates, the prices of certain fuel purchases, electricity purchases and sales, and occasionally foreign currency exchange rates. Southern Company Gas uses derivative financial instruments to limit exposure to fluctuations in natural gas prices, weather, interest rates, and commodity prices. All derivative financial instruments are recognized as either assets or liabilities on the balance sheets (included in "Other" or shown separately as "Risk Management Activities") and are measured at fair value. See Note 13 for additional information regarding fair value. Substantially all of the traditional electric operating companies' and Southern Power's bulk energy purchases and sales contracts that meet the definition of a derivative are excluded from fair value accounting requirements because they qualify for the "normal" scope exception, and are accounted for under the accrual method. Derivative contracts that qualify as cash flow hedges of anticipated transactions or are recoverable through the traditional electric operating companies' and the natural gas distribution utilities' fuel-hedging programs result in the deferral of related gains and losses in AOCI or regulatory assets and liabilities, respectively, until the hedged transactions occur. Other derivative contracts that qualify as fair value hedges are marked to market through current period income and are recorded on a net basis in the statements of income. Cash flows from derivatives are classified on the statements of cash flows in the same category as the hedged item. See Note 14 for additional information regarding derivatives. The Registrants offset fair value amounts recognized for multiple derivative instruments executed with the same counterparty under netting arrangements. The Registrants had no outstanding collateral repayment obligations or rights to reclaim collateral arising from derivative instruments recognized at December 31, 2020. The Registrants are exposed to potential losses related to financial instruments in the event of counterparties' nonperformance. The Registrants have established risk management policies and controls to determine and monitor the creditworthiness of counterparties in order to mitigate their exposure to counterparty credit risk. Southern Company Gas Southern Company Gas enters into weather derivative contracts as economic hedges of natural gas revenues in the event of warmer-than-normal weather in the Heating Season. Exchange-traded options are carried at fair value, with changes reflected in natural gas revenues. Non-exchange-traded options are accounted for using the intrinsic value method. Changes in the intrinsic value for non-exchange-traded contracts are also reflected in natural gas revenues in the statements of income. Wholesale gas services purchases natural gas for storage when the current market price paid to buy and transport natural gas plus the cost to store and finance the natural gas is less than the market price that can be received in the future, resulting in positive net natural gas revenues. NYMEX futures and OTC contracts are used to sell natural gas at that future price to substantially protect the natural gas revenues that will ultimately be realized when the stored natural gas is sold. Southern Company Gas enters into transactions to secure transportation capacity between delivery points in order to serve its customers and various markets. NYMEX futures and OTC contracts are used to capture the price differential or spread between the locations served by the capacity in order to substantially protect the natural gas revenues that will ultimately be realized when the physical flow of natural gas between delivery points occurs. These contracts generally meet the definition of derivatives and are carried at fair value on the balance sheets, with changes in fair value recorded in natural gas revenues on the statements of income in the period of change. These contracts are not designated as hedges for accounting purposes. The purchase, transportation, storage, and sale of natural gas are accounted for on a weighted average cost or accrual basis, as appropriate, rather than on the fair value basis utilized for the derivatives used to mitigate the natural gas price risk associated with the storage and transportation portfolio. Monthly demand charges are incurred for the contracted storage and transportation capacity and payments associated with asset management agreements, and these demand charges and payments are recognized on the statements of income in the period they are incurred. This difference in accounting methods can result in volatility in reported earnings, even though the economic margin is substantially unchanged from the dates the transactions were consummated. Southern Company, the traditional electric operating companies, Southern Power, and Southern Company Gas are exposed to market risks, including commodity price risk, interest rate risk, weather risk, and occasionally foreign currency exchange rate risk. To manage the volatility attributable to these exposures, each company nets its exposures, where possible, to take advantage of natural offsets and enters into various derivative transactions for the remaining exposures pursuant to each company's policies in areas such as counterparty exposure and risk management practices. Southern Company Gas' wholesale gas operations use various contracts in its commercial activities that generally meet the definition of derivatives. For the traditional electric operating companies, Southern Power, and Southern Company Gas' other businesses, each company's policy is that derivatives are to be used primarily for hedging purposes and mandates strict adherence to all applicable risk management policies. Derivative positions are monitored using techniques including, but not limited to, market valuation, value at risk, stress testing, and sensitivity analysis. Derivative instruments are recognized at fair value in the balance sheets as either assets or liabilities and are presented on a net basis. See Note 13 for additional fair value information. In the statements of cash flows, any cash impacts of settled energy-related and interest rate derivatives are recorded as operating activities. Any cash impacts of settled foreign currency derivatives are classified as operating or financing activities to correspond with the classification of the hedged interest or principal, respectively. See Note 1 under "Financial Instruments" for additional information. Energy-Related Derivatives The traditional electric operating companies, Southern Power, and Southern Company Gas enter into energy-related derivatives to hedge exposures to electricity, natural gas, and other fuel price changes. However, due to cost-based rate regulations and other various cost recovery mechanisms, the traditional electric operating companies and the natural gas distribution utilities have limited exposure to market volatility in energy-related commodity prices. Each of the traditional electric operating companies and certain of the natural gas distribution utilities of Southern Company Gas manage fuel-hedging programs, implemented per the guidelines of their respective state PSCs or other applicable state regulatory agencies, through the use of financial derivative contracts, which are expected to continue to mitigate price volatility. The traditional electric operating companies (with respect to wholesale generating capacity) and Southern Power have limited exposure to market volatility in energy-related commodity prices because their long-term sales contracts shift substantially all fuel cost responsibility to the purchaser. However, the traditional electric operating companies and Southern Power may be exposed to market volatility in energy-related commodity prices to the extent any uncontracted capacity is used to sell electricity. Southern Company Gas retains exposure to price changes that can, in a volatile energy market, be material and can adversely affect its results of operations. Southern Company Gas also enters into weather derivative contracts as economic hedges of operating margins in the event of warmer-than-normal weather. Exchange-traded options are carried at fair value, with changes reflected in operating revenues. Non-exchange-traded options are accounted for using the intrinsic value method. Changes in the intrinsic value for non-exchange-traded contracts are reflected in operating revenues. Energy-related derivative contracts are accounted for under one of three methods: • Regulatory Hedges – Energy-related derivative contracts designated as regulatory hedges relate primarily to the traditional electric operating companies' and the natural gas distribution utilities' fuel-hedging programs, where gains and losses are initially recorded as regulatory liabilities and assets, respectively, and then are included in fuel expense as the underlying fuel is used in operations and ultimately recovered through an approved cost recovery mechanism. • Cash Flow Hedges – Gains and losses on energy-related derivatives designated as cash flow hedges (which are mainly used to hedge anticipated purchases and sales) are initially deferred in AOCI before being recognized in the statements of income in the same period and in the same income statement line item as the earnings effect of the hedged transactions. • Not Designated – Gains and losses on energy-related derivative contracts that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. Some energy-related derivative contracts require physical delivery as opposed to financial settlement, and this type of derivative is both common and prevalent within the electric and natural gas industries. When an energy-related derivative contract is settled physically, any cumulative unrealized gain or loss is reversed and the contract price is recognized in the respective line item representing the actual price of the underlying goods being delivered. Interest Rate Derivatives Southern Company and certain subsidiaries may enter into interest rate derivatives to hedge exposure to changes in interest rates. The derivatives employed as hedging instruments are structured to minimize ineffectiveness. Derivatives related to existing variable rate securities or forecasted transactions are accounted for as cash flow hedges where the derivatives' fair value gains or losses are recorded in OCI and are reclassified into earnings at the same time and presented on the same income statement line item as the earnings effect of the hedged transactions. Derivatives related to existing fixed rate securities are accounted for as fair value hedges, where the derivatives' fair value gains or losses and hedged items' fair value gains or losses are both recorded directly to earnings on the same income statement line item. Fair value gains or losses on derivatives that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. Foreign Currency Derivatives Southern Company and certain subsidiaries, including Southern Power, may enter into foreign currency derivatives to hedge exposure to changes in foreign currency exchange rates, such as that arising from the issuance of debt denominated in a currency other than U.S. dollars. Derivatives related to forecasted transactions are accounted for as cash flow hedges where the derivatives' fair value gains or losses are recorded in OCI and are reclassified into earnings at the same time and on the same income statement line as the earnings effect of the hedged transactions, including foreign currency gains or losses arising from changes in the U.S. currency exchange rates. The derivatives employed as hedging instruments are structured to minimize ineffectiveness. |
Comprehensive Income | Comprehensive Income The objective of comprehensive income is to report a measure of all changes in common stock equity of an enterprise that result from transactions and other economic events of the period other than transactions with owners. Comprehensive income consists of net income attributable to the Registrant, changes in the fair value of qualifying cash flow hedges, and reclassifications for amounts included in net income. Comprehensive income also consists of certain changes in pension and other postretirement benefit plans for Southern Company, Southern Power, and Southern Company Gas. |
Variable Interest Entities | Variable Interest Entities The Registrants may hold ownership interests in a number of business ventures with varying ownership structures. Partnership interests and other variable interests are evaluated to determine if each entity is a VIE. The primary beneficiary of a VIE is required to consolidate the VIE when it has both the power to direct the activities of the VIE that most significantly impact the VIE's economic performance and the obligation to absorb losses or the right to receive benefits from the VIE that could potentially be significant to the VIE. See Note 7 for additional information regarding VIEs. Alabama Power has established a wholly-owned trust to issue preferred securities. See Note 8 under "Long-term Debt" for additional information. However, Alabama Power is not considered the primary beneficiary of the trust. Therefore, the investment in the trust is reflected as other investments, and the related loan from the trust is reflected as long-term debt in Alabama Power's balance sheets. |
Asset Retirement Obligations | AROs are computed as the present value of the estimated costs for an asset's future retirement and are recorded in the period in which the liability is incurred. The estimated costs are capitalized as part of the related long-lived asset and depreciated over the asset's useful life. In the absence of quoted market prices, AROs are estimated using present value techniques in which estimates of future cash outlays associated with the asset retirements are discounted using a credit-adjusted risk-free rate. Estimates of the timing and amounts of future cash outlays are based on projections of when and how the assets will be retired and the cost of future removal activities. Each traditional electric operating company and natural gas distribution utility has received accounting guidance from its state PSC or applicable state regulatory agency allowing the continued accrual or recovery of other retirement costs for long-lived assets that it does not have a legal obligation to retire. Accordingly, the accumulated removal costs for these obligations are reflected in the balance sheets as regulatory liabilities and amounts to be recovered are reflected in the balance sheets as regulatory assets. The ARO liabilities for the traditional electric operating companies primarily relate to facilities that are subject to the CCR Rule and the related state rules, principally ash ponds. In addition, Alabama Power and Georgia Power have retirement obligations related to the decommissioning of nuclear facilities (Alabama Power's Plant Farley and Georgia Power's ownership interests in Plant Hatch and Plant Vogtle Units 1 and 2). See "Nuclear Decommissioning" herein for additional information. Other significant AROs include various landfill sites and asbestos removal for Alabama Power, Georgia Power, and Mississippi Power and gypsum cells and mine reclamation for Mississippi Power. The ARO liability for Southern Power primarily relates to its solar and wind facilities, which are located on long-term land leases requiring the restoration of land at the end of the lease. The traditional electric operating companies and Southern Company Gas also have identified other retirement obligations, such as obligations related to certain electric transmission and distribution facilities, certain asbestos-containing material within long-term assets not subject to ongoing repair and maintenance activities, certain wireless communication towers, the disposal of polychlorinated biphenyls in certain transformers, leasehold improvements, equipment on customer property, and property associated with the Southern Company system's rail lines and natural gas pipelines. However, liabilities for the removal of these assets have not been recorded because the settlement timing for certain retirement obligations related to these assets is indeterminable and, therefore, the fair value of the retirement obligations cannot be reasonably estimated. A liability for these retirement obligations will be recognized when sufficient information becomes available to support a reasonable estimation of the ARO. Southern Company and the traditional electric operating companies will continue to recognize in their respective statements of income allowed removal costs in accordance with regulatory treatment. Any differences between costs recognized in accordance with accounting standards related to asset retirement and environmental obligations and those reflected in rates are recognized as either a regulatory asset or liability in the balance sheets as ordered by the various state PSCs. Details of the AROs included in the balance sheets are as follows: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power (*) (in millions) Balance at December 31, 2018 $ 9,394 $ 3,210 $ 5,829 $ 160 $ 84 Liabilities incurred 37 — 35 1 1 Liabilities settled (328) (127) (151) (35) — Accretion 402 145 243 7 4 Cash flow revisions 281 312 (172) 57 — Balance at December 31, 2019 $ 9,786 $ 3,540 $ 5,784 $ 190 $ 89 Liabilities incurred 19 — 10 — 9 Liabilities settled (442) (219) (185) (22) — Accretion 409 152 238 8 4 Cash flow revisions 912 501 418 — (7) Balance at December 31, 2020 $ 10,684 $ 3,974 $ 6,265 $ 176 $ 95 (*) Included in other deferred credits and liabilities on Southern Power's consolidated balance sheets. During 2019, Alabama Power recorded increases totaling approximately $312 million to its AROs primarily related to the CCR Rule and the related state rule based on management's completion of closure designs during the second and third quarters 2019 under the planned closure-in-place methodology for all but one of its ash pond facilities. During 2019, Mississippi Power recorded an increase of approximately $57 million to its AROs related to the CCR Rule, primarily associated with the ash pond facility at Plant Greene County, which is jointly owned with Alabama Power. During 2020, Alabama Power recorded increases totaling approximately $501 million to its AROs related to the CCR Rule and the related state rule primarily as a result of management's completion of the closure design for the remaining ash pond and the addition of a water treatment system to the design of another ash pond. The additional estimated costs to close these ash ponds under the planned closure-in-place methodology primarily relate to inputs from contractor bids, design revisions, and changes in the expected volume of ash handling. During the second half of 2019, Georgia Power completed an assessment of its plans to close the ash ponds at all of its generating plants in compliance with the CCR Rule and the related state rule. Cost estimates were revised to reflect further refined costs for closure plans and updates to the timing of future cash outlays. As a result, in December 2019, Georgia Power recorded a decrease of approximately $174 million to its AROs related to the CCR Rule and the related state rule. During the third quarter 2020, Georgia Power further refined the related cost estimates, including updates to long-term post-closure care requirements, market pricing, and timing of future cash outlays. As a result, in September 2020, Georgia Power recorded an increase of approximately $411 million to its AROs related to the CCR Rule and the related state rule. The cost estimates for AROs related to the disposal of CCR are based on information at December 31, 2020 using various assumptions related to closure and post-closure costs, timing of future cash outlays, inflation and discount rates, and the potential methods for complying with the CCR Rule and the related state rules. The traditional electric operating companies have periodically updated, and expect to continue periodically updating, their related cost estimates and ARO liabilities for each CCR unit as additional information related to these assumptions becomes available. Some of these updates have been, and future updates may be, material. Additionally, the closure designs and plans in the States of Alabama and Georgia are subject to approval by environmental regulatory agencies. Absent continued recovery of ARO costs through regulated rates, results of operations, cash flows, and financial condition for Southern Company and the traditional electric operating companies could be materially impacted. See Note 2 under "Georgia Power – Rate Plans" for additional information. The ultimate outcome of these matters cannot be determined at this time. |
Nuclear Decommissioning | Nuclear Decommissioning The NRC requires licensees of commercial nuclear power reactors to establish a plan for providing reasonable assurance of funds for future decommissioning. Alabama Power and Georgia Power have external trust funds (Funds) to comply with the NRC's regulations. Use of the Funds is restricted to nuclear decommissioning activities. The Funds are managed and invested in accordance with applicable requirements of various regulatory bodies, including the NRC, the FERC, and state PSCs, as well as the IRS. While Alabama Power and Georgia Power are allowed to prescribe an overall investment policy to the Funds' managers, neither Southern Company nor its subsidiaries or affiliates are allowed to engage in the day-to-day management of the Funds or to mandate individual investment decisions. Day-to-day management of the investments in the Funds is delegated to unrelated third-party managers with oversight by the management of Alabama Power and Georgia Power. The Funds' managers are authorized, within certain investment guidelines, to actively buy and sell securities at their own discretion in order to maximize the return on the Funds' investments. The Funds are invested in a tax-efficient manner in a diversified mix of equity and fixed income securities and are reported as trading securities. Alabama Power and Georgia Power record the investment securities held in the Funds at fair value, as disclosed in Note 13, as management believes that fair value best represents the nature of the Funds. Gains and losses, whether realized or unrealized, are recorded in the regulatory liability for AROs in the balance sheets and are not included in net income or OCI. Fair value adjustments and realized gains and losses are determined on a specific identification basis. The Funds at Georgia Power participate in a securities lending program through the managers of the Funds. Under this program, Georgia Power's Funds' investment securities are loaned to institutional investors for a fee. Securities loaned are fully collateralized by cash, letters of credit, and/or securities issued or guaranteed by the U.S. government or its agencies or instrumentalities. At December 31, 2020 and 2019, approximately $44 million and $28 million, respectively, of the fair market value of Georgia Power's Funds' securities were on loan and pledged to creditors under the Funds' managers' securities lending program. The fair value of the collateral received was approximately $45 million and $29 million at December 31, 2020 and 2019, respectively, and can only be sold by the borrower upon the return of the loaned securities. The collateral received is treated as a non-cash item in the statements of cash flows. Investment securities in the Funds for December 31, 2020 and 2019 were as follows: Southern Company Alabama Georgia (in millions) At December 31, 2020: Equity securities $ 1,339 $ 842 $ 497 Debt securities 851 231 620 Other securities 111 83 28 Total investment securities in the Funds $ 2,301 $ 1,156 $ 1,145 At December 31, 2019: Equity securities $ 1,159 $ 743 $ 416 Debt securities 798 218 580 Other securities 77 60 17 Total investment securities in the Funds $ 2,034 $ 1,021 $ 1,013 These amounts exclude receivables related to investment income and pending investment sales and payables related to pending investment purchases. For Southern Company and Georgia Power, these amounts include Georgia Power's investment securities pledged to creditors and collateral received and excludes payables related to Georgia Power's securities lending program. The fair value increases (decreases) of the Funds, including unrealized gains (losses) and reinvested interest and dividends and excluding the Funds' expenses, for 2020, 2019, and 2018 are shown in the table below. Southern Company Alabama Georgia (in millions) Fair value increases (decreases) 2020 $ 280 $ 142 $ 138 2019 344 194 150 2018 (67) (38) (29) Unrealized gains (losses) At December 31, 2020 $ 220 $ 121 $ 99 At December 31, 2019 259 149 110 At December 31, 2018 (183) (96) (87) The investment securities held in the Funds continue to be managed with a long-term focus. Accordingly, all purchases and sales within the Funds are presented separately in the statements of cash flows as investing cash flows, consistent with the nature of the securities and purpose for which the securities were acquired. For Alabama Power, approximately $15 million and $16 million at December 31, 2020 and 2019, respectively, previously recorded in internal reserves is being transferred into the Funds through 2040 as approved by the Alabama PSC. The NRC's minimum external funding requirements are based on a generic estimate of the cost to decommission only the radioactive portions of a nuclear unit based on the size and type of reactor. Alabama Power and Georgia Power have filed plans with the NRC designed to ensure that, over time, the deposits and earnings of the Funds will provide the minimum funding amounts prescribed by the NRC. At December 31, 2020 and 2019, the accumulated provisions for the external decommissioning trust funds were as follows: 2020 2019 (in millions) Alabama Power Plant Farley $ 1,156 $ 1,021 Georgia Power Plant Hatch $ 716 $ 634 Plant Vogtle Units 1 and 2 429 379 Total $ 1,145 $ 1,013 Site study cost is the estimate to decommission a specific facility as of the site study year. The decommissioning cost estimates are based on prompt dismantlement and removal of the plant from service. The actual decommissioning costs may vary from these estimates because of changes in the assumed date of decommissioning, changes in NRC requirements, or changes in the assumptions used in making these estimates. The estimated costs of decommissioning at December 31, 2020 based on the most current studies, which were each performed in 2018, were as follows: Plant Plant Hatch (*) Plant Vogtle Units 1 and 2 (*) Decommissioning periods: Beginning year 2037 2034 2047 Completion year 2076 2075 2079 (in millions) Site study costs: Radiated structures $ 1,234 $ 734 $ 601 Spent fuel management 387 172 162 Non-radiated structures 99 56 79 Total site study costs $ 1,720 $ 962 $ 842 (*) Based on Georgia Power's ownership interests. For ratemaking purposes, Alabama Power's decommissioning costs are based on the site study and Georgia Power's decommissioning costs are based on the NRC generic estimate to decommission the radioactive portion of the facilities and the site study estimate for spent fuel management as of 2018. Significant assumptions used to determine these costs for ratemaking were an estimated inflation rate of 4.5% and 2.75% for Alabama Power and Georgia Power, respectively, and an estimated trust earnings rate of 7.0% and 4.75% for Alabama Power and Georgia Power, respectively. Amounts previously contributed to the Funds for Plant Farley are currently projected to be adequate to meet the decommissioning obligations. Alabama Power will continue to provide site-specific estimates of the decommissioning costs and related projections of funds in the external trust to the Alabama PSC and, if necessary, would seek the Alabama PSC's approval to address any changes in a manner consistent with NRC and other applicable requirements. Effective January 1, 2020, in connection with the 2019 ARP, Georgia Power's annual decommissioning cost for ratemaking is a total of $4 million for Plant Hatch and Plant Vogtle Units 1 and 2. Georgia Power's annual decommissioning cost for ratemaking in 2019 totaled $5 million. |
Fair Value Measurement | Fair value measurements are based on inputs of observable and unobservable market data that a market participant would use in pricing the asset or liability. The use of observable inputs is maximized where available and the use of unobservable inputs is minimized for fair value measurement and reflects a three-tier fair value hierarchy that prioritizes inputs to valuation techniques used for fair value measurement. • Level 1 consists of observable market data in an active market for identical assets or liabilities. • Level 2 consists of observable market data, other than that included in Level 1, that is either directly or indirectly observable. • Level 3 consists of unobservable market data. The input may reflect the assumptions of each Registrant of what a market participant would use in pricing an asset or liability. If there is little available market data, then each Registrant's own assumptions are the best available information. In the case of multiple inputs being used in a fair value measurement, the lowest level input that is significant to the fair value measurement represents the level in the fair value hierarchy in which the fair value measurement is reported. Valuation Methodologies The energy-related derivatives primarily consist of exchange-traded and over-the-counter financial products for natural gas and physical power products, including, from time to time, basis swaps. These are standard products used within the energy industry and are valued using the market approach. The inputs used are mainly from observable market sources, such as forward natural gas prices, power prices, implied volatility, and overnight index swap interest rates. Interest rate derivatives are also standard over-the-counter products that are valued using observable market data and assumptions commonly used by market participants. The fair value of interest rate derivatives reflects the net present value of expected payments and receipts under the swap agreement based on the market's expectation of future interest rates. Additional inputs to the net present value calculation may include the contract terms, counterparty credit risk, and occasionally, implied volatility of interest rate options. The fair value of cross-currency swaps reflects the net present value of expected payments and receipts under the swap agreement based on the market's expectation of future foreign currency exchange rates. Additional inputs to the net present value calculation may include the contract terms, counterparty credit risk, and discount rates. The interest rate derivatives and cross-currency swaps are categorized as Level 2 under Fair Value Measurements as these inputs are based on observable data and valuations of similar instruments. See Note 14 for additional information on how these derivatives are used. For fair value measurements of the investments within the nuclear decommissioning trusts and the non-qualified deferred compensation trusts, external pricing vendors are designated for each asset class with each security specifically assigned a primary pricing source. For investments held within commingled funds, fair value is determined at the end of each business day through the net asset value, which is established by obtaining the underlying securities' individual prices from the primary pricing source. A market price secured from the primary source vendor is then evaluated by management in its valuation of the assets within the trusts. As a general approach, fixed income market pricing vendors gather market data (including indices and market research reports) and integrate relative credit information, observed market movements, and sector news into proprietary pricing models, pricing systems, and mathematical tools. Dealer quotes and other market information, including live trading levels and pricing analysts' judgments, are also obtained when available. The NRC requires licensees of commissioned nuclear power reactors to establish a plan for providing reasonable assurance of funds for future decommissioning. See Note 6 under "Nuclear Decommissioning" for additional information. Southern Power has contingent payment obligations related to certain acquisitions whereby it is primarily obligated to make generation-based payments to the seller, which commenced at the commercial operation of the respective facility and continue through 2026. The obligations are categorized as Level 3 under Fair Value Measurements as the fair value is determined using significant unobservable inputs for the forecasted facility generation in MW-hours, as well as other inputs such as a fixed dollar amount per MW-hour, and a discount rate. The fair value of contingent consideration reflects the net present value of expected payments and any periodic change arising from forecasted generation is expected to be immaterial. "Other investments" include investments traded in the open market that have maturities greater than 90 days, which are categorized as Level 2 under Fair Value Measurements and are comprised of corporate bonds, bank certificates of deposit, treasury bonds, and/or agency bonds. |
SUMMARY OF SIGNIFICANT ACCOUN_3
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Accounting Policies [Abstract] | |
Schedule of costs for affiliate transactions | Costs for these services from SCS in 2020, 2019, and 2018 were as follows: Alabama Georgia Mississippi Southern Southern Company Gas (in millions) 2020 $ 478 $ 639 $ 149 $ 87 $ 237 2019 527 704 118 90 183 2018 508 653 104 98 194 Mississippi Southern (in millions) 2020 $ 4 $ 8 2019 3 14 2018 15 41 Alabama Georgia Southern Southern Company Gas (in millions) 2020 $ 15 $ 108 $ 29 $ 29 2019 17 99 28 31 2018 8 101 25 32 Georgia Southern (in millions) 2020 $ — $ 26 2019 4 64 2018 21 119 2020 2019 2018 Alabama Power 2.6 % 3.1 % 3.0 % Georgia Power 3.0 % 2.6 % 2.6 % Mississippi Power 3.7 % 3.7 % 4.2 % Southern Company Gas 2.8 % 2.9 % 2.9 % |
Schedule of concentration of revenue | The following table shows the percentage of total revenues for Southern Power's top three customers for each of the years presented: 2020 2019 2018 Southern California Edison 9.4 % 6.8 % 6.2 % Georgia Power 8.0 % 9.0 % 9.8 % Duke Energy Corporation 6.7 % N/A 6.8 % Morgan Stanley Capital Group N/A 4.9 % N/A |
Schedule of total AFUDC and interest capitalized | Total AFUDC and interest capitalized for the Registrants in 2020, 2019, and 2018 was as follows: Southern Company Alabama Georgia (*) Mississippi Southern Southern Company Gas (in millions) 2020 $ 230 $ 61 $ 138 $ 1 $ 11 $ 18 2019 202 71 103 — 15 13 2018 210 84 94 — 17 14 (*) See Note 2 under "Georgia Power – Nuclear Construction" for information on the inclusion of a portion of construction costs related to Plant Vogtle Units 3 and 4 in Georgia Power's rate base. |
Schedule of average AFUDC composite rates | The average AFUDC composite rates for 2020, 2019, and 2018 for the traditional electric operating companies and the natural gas distribution utilities were as follows: 2020 2019 2018 Alabama Power 8.1 % 8.4 % 8.3 % Georgia Power (*) 6.9 % 6.9 % 7.3 % Mississippi Power 5.4 % 7.3 % 3.3 % Southern Company Gas: Atlanta Gas Light 7.7 % 7.8 % 7.9 % Chattanooga Gas 7.1 % 7.1 % 7.4 % Nicor Gas 0.7 % 2.3 % 2.1 % (*) Excludes AFUDC related to the construction of Plant Vogtle Units 3 and 4. See Note 2 under "Georgia Power – Nuclear Construction" for additional information. |
Schedule of goodwill balances | At December 31, 2020 and 2019, goodwill was as follows: Goodwill (in millions) Southern Company $ 5,280 Southern Company Gas: Gas distribution operations $ 4,034 Gas marketing services 981 Southern Company Gas total $ 5,015 |
Schedule of intangible assets subject to amortization | At December 31, 2020 and 2019, other intangible assets were as follows: At December 31, 2020 At December 31, 2019 Gross Carrying Amount Accumulated Amortization Other Gross Carrying Amount Accumulated Amortization Other (in millions) (in millions) Southern Company Other intangible assets subject to amortization: Customer relationships $ 212 $ (135) $ 77 $ 212 $ (116) $ 96 Trade names 64 (31) 33 64 (25) 39 Storage and transportation contracts 64 (64) — 64 (62) 2 PPA fair value adjustments 390 (89) 301 390 (69) 321 Other 10 (9) 1 11 (8) 3 Total other intangible assets subject to amortization $ 740 $ (328) $ 412 $ 741 $ (280) $ 461 Other intangible assets not subject to amortization: Federal Communications Commission licenses 75 — 75 75 — 75 Total other intangible assets $ 815 $ (328) $ 487 $ 816 $ (280) $ 536 Southern Power Other intangible assets subject to amortization: PPA fair value adjustments $ 390 $ (89) $ 301 $ 390 $ (69) $ 321 Southern Company Gas Other intangible assets subject to amortization: Gas marketing services Customer relationships $ 156 $ (119) $ 37 $ 156 $ (104) $ 52 Trade names 26 (12) 14 26 (10) 16 Wholesale gas services Storage and transportation contracts 64 (64) — 64 (62) 2 Total other intangible assets subject to amortization $ 246 $ (195) $ 51 $ 246 $ (176) $ 70 |
Schedule of intangible assets not subject to amortization | At December 31, 2020 and 2019, other intangible assets were as follows: At December 31, 2020 At December 31, 2019 Gross Carrying Amount Accumulated Amortization Other Gross Carrying Amount Accumulated Amortization Other (in millions) (in millions) Southern Company Other intangible assets subject to amortization: Customer relationships $ 212 $ (135) $ 77 $ 212 $ (116) $ 96 Trade names 64 (31) 33 64 (25) 39 Storage and transportation contracts 64 (64) — 64 (62) 2 PPA fair value adjustments 390 (89) 301 390 (69) 321 Other 10 (9) 1 11 (8) 3 Total other intangible assets subject to amortization $ 740 $ (328) $ 412 $ 741 $ (280) $ 461 Other intangible assets not subject to amortization: Federal Communications Commission licenses 75 — 75 75 — 75 Total other intangible assets $ 815 $ (328) $ 487 $ 816 $ (280) $ 536 Southern Power Other intangible assets subject to amortization: PPA fair value adjustments $ 390 $ (89) $ 301 $ 390 $ (69) $ 321 Southern Company Gas Other intangible assets subject to amortization: Gas marketing services Customer relationships $ 156 $ (119) $ 37 $ 156 $ (104) $ 52 Trade names 26 (12) 14 26 (10) 16 Wholesale gas services Storage and transportation contracts 64 (64) — 64 (62) 2 Total other intangible assets subject to amortization $ 246 $ (195) $ 51 $ 246 $ (176) $ 70 |
Schedule of amortization associated with other intangible assets | Amortization associated with other intangible assets in 2020, 2019, and 2018 was as follows: 2020 2019 2018 (in millions) Southern Company (a) $ 49 $ 61 $ 89 Southern Power (b) 20 19 25 Southern Company Gas: Gas marketing services $ 17 $ 23 $ 32 Wholesale gas services (b) 2 8 20 Southern Company Gas total $ 19 $ 31 $ 52 (a) Includes $22 million, $27 million, and $45 million in 2020, 2019, and 2018, respectively, recorded as a reduction to operating revenues. (b) Recorded as a reduction to operating revenues. |
Schedule of amortization of other intangible assets | At December 31, 2020, the estimated amortization associated with other intangible assets for the next five years is as follows: 2021 2022 2023 2024 2025 (in millions) Southern Company $ 43 $ 39 $ 37 $ 35 $ 32 Southern Power 20 20 20 20 20 Southern Company Gas 14 11 9 7 6 |
Schedule of storm damage reserves | In accordance with their respective state PSC orders, the traditional electric operating companies accrued the following amounts related to storm damage recovery in 2020, 2019, and 2018: Southern Company (a)(b) Alabama (b) Georgia Mississippi (in millions) 2020 $ 326 $ 112 $ 213 $ 1 2019 170 139 30 1 2018 74 16 30 1 (a) Includes accruals at Gulf Power of $26.9 million in 2018. See Note 15 under "Southern Company" for information regarding the sale of Gulf Power. (b) Includes $39 million applied in 2019 to Alabama Power's NDR from its remaining excess deferred income tax regulatory liability balance in accordance with an Alabama PSC order. |
Schedule of net investment in domestic and international leveraged leases | Southern Company's net investment in leveraged leases consists of the following at December 31: 2020 (*) 2019 (in millions) Net rentals receivable $ 734 $ 1,410 Unearned income (178) (622) Investment in leveraged leases 556 788 Deferred taxes from leveraged leases (7) (238) Net investment in leveraged leases $ 549 $ 550 (*) Excludes the investment classified as held for sale at December 31, 2020. See Note 15 under "Assets Held for Sale" for additional information. |
Summary of the components of income from leveraged leases | The following table provides a summary of the components of income related to leveraged lease investments. Income was impacted in 2020 and 2019 by the impairment charges discussed in Note 3 under "Other Matters – Southern Company." 2020 2019 2018 (in millions) Pretax leveraged lease income (loss) $ (180) $ 11 $ 25 Income tax benefit (expense) 98 — (6) Net leveraged lease income (loss) $ (82) $ 11 $ 19 |
Schedule of AOCI (loss) balances, net of tax effects | AOCI (loss) balances, net of tax effects, for Southern Company, Southern Power, and Southern Company Gas were as follows: Qualifying Pension and Other Accumulated Other (in millions) Southern Company Balance at December 31, 2019 $ (179) $ (142) $ (321) Current period change (30) (45) (75) Balance at December 31, 2020 (*) $ (209) $ (187) $ (395) Southern Power Balance at December 31, 2019 $ 11 $ (37) $ (26) Current period change (32) (10) (42) Balance at December 31, 2020 (*) $ (21) $ (47) $ (67) Southern Company Gas Balance at December 31, 2019 $ (6) $ 13 $ 7 Current period change (14) (15) (29) Balance at December 31, 2020 $ (20) $ (2) $ (22) (*) May not add due to rounding. |
REGULATORY MATTERS (Tables)
REGULATORY MATTERS (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Regulated Operations [Abstract] | |
Schedule of regulatory assets | Details of regulatory assets and (liabilities) reflected in the balance sheets at December 31, 2020 and 2019 are provided in the following tables: Southern Company Alabama Power Georgia Power Mississippi Power Southern Company Gas (in millions) At December 31, 2020 AROs (a)(s) $ 5,147 $ 1,470 $ 3,457 $ 212 $ — Retiree benefit plans (b)(s) 4,958 1,265 1,647 238 187 Remaining net book value of retired assets (c) 1,183 632 527 24 — Deferred income tax charges (d) 801 235 531 32 — Environmental remediation (e)(s) 310 — 41 — 269 Loss on reacquired debt (f) 304 47 248 6 3 Storm damage (g) 262 — 262 — — Vacation pay (h)(s) 207 80 104 10 13 Under recovered regulatory clause revenues (i) 185 58 — 52 75 Regulatory clauses (j) 142 142 — — — Nuclear outage (k) 101 61 40 — — Long-term debt fair value adjustment (l) 92 — — — 92 Kemper County energy facility assets, net (m) 50 — — 50 — Plant Daniel Units 3 and 4 (n) 32 — — 32 — Other regulatory assets (o) 205 52 68 4 81 Deferred income tax credits (d) (6,016) (2,016) (2,805) (320) (847) Other cost of removal obligations (a) (1,999) (335) 212 (194) (1,649) Over recovered regulatory clause revenues (i) (185) (46) (44) — (95) Storm/property damage reserves (p) (81) (77) — (4) — Customer refunds (q) (56) (50) (6) — — Other regulatory liabilities (r) (149) (37) (30) (6) (54) Total regulatory assets (liabilities), net $ 5,493 $ 1,481 $ 4,252 $ 136 $ (1,925) Southern Company Alabama Power Georgia Power Mississippi Power Southern Company Gas (in millions) At December 31, 2019 Retiree benefit plans (b)(s) $ 4,423 $ 1,131 $ 1,516 $ 213 $ 167 AROs (a)(s) 4,381 1,043 3,119 210 — Remaining net book value of retired assets (c) 1,275 649 596 30 — Deferred income tax charges (d) 803 245 523 33 — Storm damage (g) 410 — 410 — — Environmental remediation (e)(s) 349 — 52 — 296 Loss on reacquired debt (f) 323 52 262 6 4 Vacation pay (h)(s) 186 72 93 9 11 Under recovered regulatory clause revenues (i) 159 40 — 47 72 Regulatory clauses (j) 142 142 — — — Long-term debt fair value adjustment (l) 107 — — — 107 Nuclear outage (k) 105 78 27 — — Fuel-hedging (realized and unrealized) losses (t) 102 22 53 27 — Kemper County energy facility assets, net (m) 61 — — 61 — Plant Daniel Units 3 and 4 (n) 34 — — 34 — Other regulatory assets (o) 127 45 23 6 53 Deferred income tax credits (d) (6,301) (1,960) (3,078) (358) (874) Other cost of removal obligations (a) (2,084) (412) 156 (189) (1,606) Customer refunds (q) (285) (56) (229) — — Over recovered regulatory clause revenues (i) (205) (112) (10) — (82) Storm/property damage reserves (p) (204) (150) — (55) — Other regulatory liabilities (r) (70) (19) (6) (10) (22) Total regulatory assets (liabilities), net $ 3,838 $ 810 $ 3,507 $ 64 $ (1,874) Unless otherwise noted, the following recovery and amortization periods for these regulatory assets and (liabilities) have been approved by the respective state PSC or regulatory agency: (a) AROs and other cost of removal obligations generally are recorded over the related property lives, which may range up to 53 years for Alabama Power, 60 years for Georgia Power, 55 years for Mississippi Power, and 80 years for Southern Company Gas. AROs and cost of removal obligations will be settled and trued up following completion of the related activities. Effective January 1, 2020, Georgia Power is recovering CCR AROs, including past under recovered costs and estimated annual compliance costs, over three-year periods ending December 31, 2022, 2023, and 2024 through its Environmental Compliance Cost Recovery (ECCR) tariff, as discussed further under "Georgia Power – Rate Plans" herein. See Note 6 for additional information on AROs. (b) Recovered and amortized over the average remaining service period, which may range up to 13 years for Alabama Power, 13 years for Georgia Power, 14 years for Mississippi Power, and 13 years for Southern Company Gas. Southern Company's balances also include amounts at SCS and Southern Nuclear that are allocated to the applicable regulated utilities. See Note 11 for additional information. (c) Alabama Power : Primarily represents the net book value of Plant Gorgas Units 8, 9, and 10 ($585 million at December 31, 2020). Being amortized over remaining periods not exceeding 17 years (through 2037). Georgia Power : Net book values of Plant Hammond Units 1 through 4 and Plant Branch Units 2 through 4 (totaling $503 million at December 31, 2020) are being amortized over remaining periods of between two Mississippi Power : Represents net book value associated with Plant Watson and Plant Greene County. The retail and wholesale portions totaling approximately $11 million and $13 million at December 31, 2020, respectively, are being amortized over a four-year period through 2024 and a 10-year period through 2030, respectively. See "Mississippi Power – Environmental Compliance Overview Plan" herein for additional information. (d) Deferred income tax charges are recovered and deferred income tax credits are amortized over the related property lives, which may range up to 53 years for Alabama Power, 60 years for Georgia Power, 55 years for Mississippi Power, and 80 years for Southern Company Gas. See Note 10 for additional information. Included in the deferred income tax charges are amounts ($8 million, $9 million, and $1 million for Alabama Power, Georgia Power, and Mississippi Power, respectively, at December 31, 2020) for the retiree Medicare drug subsidy, which are being recovered and amortized through 2027, 2022, and 2024 for Alabama Power, Georgia Power, and Mississippi Power, respectively. As a result of the Tax Reform Legislation, these accounts include certain deferred income tax assets and liabilities not subject to normalization, as described further below: Alabama Power: Related amounts are being recovered and amortized ratably over the related property lives. Georgia Power: Related amounts at December 31, 2020 include $145 million of deferred income tax assets related to CWIP for Plant Vogtle Units 3 and 4 and approximately $440 million of deferred income tax liabilities. The recovery of deferred income tax assets related to CWIP for Plant Vogtle Units 3 and 4 is expected to be determined in a future regulatory proceeding. Effective January 1, 2020, the deferred income tax liabilities are being amortized through 2022. Mississippi Power: Related amounts at December 31, 2020 include $74 million of deferred income tax liabilities, consisting of the retail portion of $66 million being amortized over three years (through 2023) and the wholesale portion of $9 million being amortized over two years (through 2021). See "Mississippi Power – 2019 Base Rate Case" and " – Municipal and Rural Associations Tariff" herein for additional information. Southern Company Gas : Related amounts at December 31, 2020 include $8 million of deferred income tax liabilities, which are being amortized through 2024. See "Southern Company Gas – Rate Proceedings" herein for additional information. (e) Georgia Power is recovering $12 million annually for environmental remediation. Southern Company Gas' costs are recovered through environmental cost recovery mechanisms when the remediation work is performed. See Note 3 under "Environmental Remediation" for additional information. (f) Recovered over either the remaining life of the original issue or, if refinanced, over the remaining life of the new issue. At December 31, 2020, the remaining amortization periods do not exceed 28 years for Alabama Power, 32 years for Georgia Power, eight years for Mississippi Power, and seven years for Southern Company Gas. (g) Georgia Power is recovering approximately $213 million annually for storm damage. See "Georgia Power – Storm Damage Recovery" herein and Note 1 under "Storm Damage Reserves" for additional information. (h) Recorded as earned by employees and recovered as paid, generally within one year. Includes both vacation and banked holiday pay, if applicable. (i) Alabama Power : Balances are recorded monthly and expected to be recovered or returned within nine years. Recovery periods could change based on several factors including changes in cost estimates, load forecasts, and timing of rate adjustments. See "Alabama Power – Rate CNP PPA," " – Rate CNP Compliance," and " – Rate ECR" herein for additional information. Georgia Power : Balances are recorded monthly and expected to be recovered or returned within two years. See "Georgia Power – Rate Plans" herein for additional information. Mississippi Power : At December 31, 2020, $37 million is being amortized over a four-yea Southern Company Gas : Balances are recorded and recovered or amortized over periods generally not exceeding five years. In addition to natural gas cost recovery mechanisms, the natural gas distribution utilities have various other cost recovery mechanisms for the recovery of costs, including those related to infrastructure replacement programs. (j) Will be amortized concurrently with the effective date of Alabama Power's next depreciation study, which is expected to occur no later than 2023. (k) Nuclear outage costs are deferred to a regulatory asset when incurred and amortized over a subsequent period of 18 months for Alabama Power and up to 24 months for Georgia Power. See Note 5 for additional information. (l) Recovered over the remaining lives of the original debt issuances at acquisition, which range up to 18 years at December 31, 2020. (m) Includes $62 million of regulatory assets and $12 million of regulatory liabilities at December 31, 2020. The retail portion includes $50 million of regulatory assets and $12 million of regulatory liabilities that are expected to be fully amortized by 2024 and 2023, respectively. The wholesale portion includes $12 million of regulatory assets that are expected to be fully amortized by 2029. See Note 3 under "Mississippi Power – Other Matters – Kemper County Energy Facility" for additional information. (n) Represents the difference between Mississippi Power's revenue requirement for Plant Daniel Units 3 and 4 under purchase accounting and operating lease accounting, which is expected to be amortized over a period to be determined in future retail and wholesale rate filings. (o) Except as otherwise noted, comprised of numerous immaterial components with remaining amortization periods generally not exceeding 23 years for Alabama Power, three years for Georgia Power, four years for Mississippi Power, and 20 years for Southern Company Gas at December 31, 2020. Balances at December 31, 2020 include deferred COVID-19 costs (except for Alabama Power), as discussed further under "Deferral of Incremental COVID-19 Costs" for each applicable Registrant herein. Balances for Georgia Power also include certain operations and maintenance costs associated with software and cloud computing projects for which the recovery period will be determined in its next base rate case. (p) Amortized as related expenses are incurred. See "Alabama Power – Rate NDR" and "Mississippi Power – System Restoration Rider" herein for additional information. (q) Primarily includes approximately $50 million and $53 million at December 31, 2020 and 2019, respectively, for Alabama Power and $110 million at December 31, 2019 for Georgia Power as a result of each company exceeding its allowed retail return range. Georgia Power's December 31, 2019 balance also includes approximately $105 million pursuant to the Georgia Power Tax Reform Settlement Agreement. Georgia Power's balances also include immaterial amounts related to refunds for transmission service customers. See "Alabama Power" and "Georgia Power – Rate Plans" herein for additional information. (r) Comprised of numerous immaterial components with remaining amortization periods generally not exceeding 17 years for Alabama Power, 12 years for Georgia Power, three years for Mississippi Power, and 20 years for Southern Company Gas at December 31, 2020. (s) Generally not earning a return as they are excluded from rate base or are offset in rate base by a corresponding asset or liability. (t) Fuel-hedging assets and liabilities are recorded over the life of the underlying hedged purchase contracts. Upon final settlement, actual costs incurred are recovered through the applicable traditional electric operating company's fuel cost recovery mechanism. Purchase contracts generally do not exceed three and a half years for Alabama Power, three years for Georgia Power, and five years for Mississippi Power. Immaterial amounts at December 31, 2020 are included in other regulatory assets and liabilities. The following table illustrates Southern Company Gas' authorized ratemaking amounts that are not recognized on its balance sheets. These amounts are primarily composed of an allowed equity rate of return on assets associated with certain regulatory infrastructure programs. These amounts will be recognized as revenues in Southern Company Gas' financial statements in the periods they are billable to customers, the majority of which will be recovered by 2025. December 31, 2020 December 31, 2019 (in millions) Atlanta Gas Light $ 59 $ 70 Virginia Natural Gas 10 10 Nicor Gas 3 2 Total $ 72 $ 82 |
Schedule of regulatory liabilities | Details of regulatory assets and (liabilities) reflected in the balance sheets at December 31, 2020 and 2019 are provided in the following tables: Southern Company Alabama Power Georgia Power Mississippi Power Southern Company Gas (in millions) At December 31, 2020 AROs (a)(s) $ 5,147 $ 1,470 $ 3,457 $ 212 $ — Retiree benefit plans (b)(s) 4,958 1,265 1,647 238 187 Remaining net book value of retired assets (c) 1,183 632 527 24 — Deferred income tax charges (d) 801 235 531 32 — Environmental remediation (e)(s) 310 — 41 — 269 Loss on reacquired debt (f) 304 47 248 6 3 Storm damage (g) 262 — 262 — — Vacation pay (h)(s) 207 80 104 10 13 Under recovered regulatory clause revenues (i) 185 58 — 52 75 Regulatory clauses (j) 142 142 — — — Nuclear outage (k) 101 61 40 — — Long-term debt fair value adjustment (l) 92 — — — 92 Kemper County energy facility assets, net (m) 50 — — 50 — Plant Daniel Units 3 and 4 (n) 32 — — 32 — Other regulatory assets (o) 205 52 68 4 81 Deferred income tax credits (d) (6,016) (2,016) (2,805) (320) (847) Other cost of removal obligations (a) (1,999) (335) 212 (194) (1,649) Over recovered regulatory clause revenues (i) (185) (46) (44) — (95) Storm/property damage reserves (p) (81) (77) — (4) — Customer refunds (q) (56) (50) (6) — — Other regulatory liabilities (r) (149) (37) (30) (6) (54) Total regulatory assets (liabilities), net $ 5,493 $ 1,481 $ 4,252 $ 136 $ (1,925) Southern Company Alabama Power Georgia Power Mississippi Power Southern Company Gas (in millions) At December 31, 2019 Retiree benefit plans (b)(s) $ 4,423 $ 1,131 $ 1,516 $ 213 $ 167 AROs (a)(s) 4,381 1,043 3,119 210 — Remaining net book value of retired assets (c) 1,275 649 596 30 — Deferred income tax charges (d) 803 245 523 33 — Storm damage (g) 410 — 410 — — Environmental remediation (e)(s) 349 — 52 — 296 Loss on reacquired debt (f) 323 52 262 6 4 Vacation pay (h)(s) 186 72 93 9 11 Under recovered regulatory clause revenues (i) 159 40 — 47 72 Regulatory clauses (j) 142 142 — — — Long-term debt fair value adjustment (l) 107 — — — 107 Nuclear outage (k) 105 78 27 — — Fuel-hedging (realized and unrealized) losses (t) 102 22 53 27 — Kemper County energy facility assets, net (m) 61 — — 61 — Plant Daniel Units 3 and 4 (n) 34 — — 34 — Other regulatory assets (o) 127 45 23 6 53 Deferred income tax credits (d) (6,301) (1,960) (3,078) (358) (874) Other cost of removal obligations (a) (2,084) (412) 156 (189) (1,606) Customer refunds (q) (285) (56) (229) — — Over recovered regulatory clause revenues (i) (205) (112) (10) — (82) Storm/property damage reserves (p) (204) (150) — (55) — Other regulatory liabilities (r) (70) (19) (6) (10) (22) Total regulatory assets (liabilities), net $ 3,838 $ 810 $ 3,507 $ 64 $ (1,874) Unless otherwise noted, the following recovery and amortization periods for these regulatory assets and (liabilities) have been approved by the respective state PSC or regulatory agency: (a) AROs and other cost of removal obligations generally are recorded over the related property lives, which may range up to 53 years for Alabama Power, 60 years for Georgia Power, 55 years for Mississippi Power, and 80 years for Southern Company Gas. AROs and cost of removal obligations will be settled and trued up following completion of the related activities. Effective January 1, 2020, Georgia Power is recovering CCR AROs, including past under recovered costs and estimated annual compliance costs, over three-year periods ending December 31, 2022, 2023, and 2024 through its Environmental Compliance Cost Recovery (ECCR) tariff, as discussed further under "Georgia Power – Rate Plans" herein. See Note 6 for additional information on AROs. (b) Recovered and amortized over the average remaining service period, which may range up to 13 years for Alabama Power, 13 years for Georgia Power, 14 years for Mississippi Power, and 13 years for Southern Company Gas. Southern Company's balances also include amounts at SCS and Southern Nuclear that are allocated to the applicable regulated utilities. See Note 11 for additional information. (c) Alabama Power : Primarily represents the net book value of Plant Gorgas Units 8, 9, and 10 ($585 million at December 31, 2020). Being amortized over remaining periods not exceeding 17 years (through 2037). Georgia Power : Net book values of Plant Hammond Units 1 through 4 and Plant Branch Units 2 through 4 (totaling $503 million at December 31, 2020) are being amortized over remaining periods of between two Mississippi Power : Represents net book value associated with Plant Watson and Plant Greene County. The retail and wholesale portions totaling approximately $11 million and $13 million at December 31, 2020, respectively, are being amortized over a four-year period through 2024 and a 10-year period through 2030, respectively. See "Mississippi Power – Environmental Compliance Overview Plan" herein for additional information. (d) Deferred income tax charges are recovered and deferred income tax credits are amortized over the related property lives, which may range up to 53 years for Alabama Power, 60 years for Georgia Power, 55 years for Mississippi Power, and 80 years for Southern Company Gas. See Note 10 for additional information. Included in the deferred income tax charges are amounts ($8 million, $9 million, and $1 million for Alabama Power, Georgia Power, and Mississippi Power, respectively, at December 31, 2020) for the retiree Medicare drug subsidy, which are being recovered and amortized through 2027, 2022, and 2024 for Alabama Power, Georgia Power, and Mississippi Power, respectively. As a result of the Tax Reform Legislation, these accounts include certain deferred income tax assets and liabilities not subject to normalization, as described further below: Alabama Power: Related amounts are being recovered and amortized ratably over the related property lives. Georgia Power: Related amounts at December 31, 2020 include $145 million of deferred income tax assets related to CWIP for Plant Vogtle Units 3 and 4 and approximately $440 million of deferred income tax liabilities. The recovery of deferred income tax assets related to CWIP for Plant Vogtle Units 3 and 4 is expected to be determined in a future regulatory proceeding. Effective January 1, 2020, the deferred income tax liabilities are being amortized through 2022. Mississippi Power: Related amounts at December 31, 2020 include $74 million of deferred income tax liabilities, consisting of the retail portion of $66 million being amortized over three years (through 2023) and the wholesale portion of $9 million being amortized over two years (through 2021). See "Mississippi Power – 2019 Base Rate Case" and " – Municipal and Rural Associations Tariff" herein for additional information. Southern Company Gas : Related amounts at December 31, 2020 include $8 million of deferred income tax liabilities, which are being amortized through 2024. See "Southern Company Gas – Rate Proceedings" herein for additional information. (e) Georgia Power is recovering $12 million annually for environmental remediation. Southern Company Gas' costs are recovered through environmental cost recovery mechanisms when the remediation work is performed. See Note 3 under "Environmental Remediation" for additional information. (f) Recovered over either the remaining life of the original issue or, if refinanced, over the remaining life of the new issue. At December 31, 2020, the remaining amortization periods do not exceed 28 years for Alabama Power, 32 years for Georgia Power, eight years for Mississippi Power, and seven years for Southern Company Gas. (g) Georgia Power is recovering approximately $213 million annually for storm damage. See "Georgia Power – Storm Damage Recovery" herein and Note 1 under "Storm Damage Reserves" for additional information. (h) Recorded as earned by employees and recovered as paid, generally within one year. Includes both vacation and banked holiday pay, if applicable. (i) Alabama Power : Balances are recorded monthly and expected to be recovered or returned within nine years. Recovery periods could change based on several factors including changes in cost estimates, load forecasts, and timing of rate adjustments. See "Alabama Power – Rate CNP PPA," " – Rate CNP Compliance," and " – Rate ECR" herein for additional information. Georgia Power : Balances are recorded monthly and expected to be recovered or returned within two years. See "Georgia Power – Rate Plans" herein for additional information. Mississippi Power : At December 31, 2020, $37 million is being amortized over a four-yea Southern Company Gas : Balances are recorded and recovered or amortized over periods generally not exceeding five years. In addition to natural gas cost recovery mechanisms, the natural gas distribution utilities have various other cost recovery mechanisms for the recovery of costs, including those related to infrastructure replacement programs. (j) Will be amortized concurrently with the effective date of Alabama Power's next depreciation study, which is expected to occur no later than 2023. (k) Nuclear outage costs are deferred to a regulatory asset when incurred and amortized over a subsequent period of 18 months for Alabama Power and up to 24 months for Georgia Power. See Note 5 for additional information. (l) Recovered over the remaining lives of the original debt issuances at acquisition, which range up to 18 years at December 31, 2020. (m) Includes $62 million of regulatory assets and $12 million of regulatory liabilities at December 31, 2020. The retail portion includes $50 million of regulatory assets and $12 million of regulatory liabilities that are expected to be fully amortized by 2024 and 2023, respectively. The wholesale portion includes $12 million of regulatory assets that are expected to be fully amortized by 2029. See Note 3 under "Mississippi Power – Other Matters – Kemper County Energy Facility" for additional information. (n) Represents the difference between Mississippi Power's revenue requirement for Plant Daniel Units 3 and 4 under purchase accounting and operating lease accounting, which is expected to be amortized over a period to be determined in future retail and wholesale rate filings. (o) Except as otherwise noted, comprised of numerous immaterial components with remaining amortization periods generally not exceeding 23 years for Alabama Power, three years for Georgia Power, four years for Mississippi Power, and 20 years for Southern Company Gas at December 31, 2020. Balances at December 31, 2020 include deferred COVID-19 costs (except for Alabama Power), as discussed further under "Deferral of Incremental COVID-19 Costs" for each applicable Registrant herein. Balances for Georgia Power also include certain operations and maintenance costs associated with software and cloud computing projects for which the recovery period will be determined in its next base rate case. (p) Amortized as related expenses are incurred. See "Alabama Power – Rate NDR" and "Mississippi Power – System Restoration Rider" herein for additional information. (q) Primarily includes approximately $50 million and $53 million at December 31, 2020 and 2019, respectively, for Alabama Power and $110 million at December 31, 2019 for Georgia Power as a result of each company exceeding its allowed retail return range. Georgia Power's December 31, 2019 balance also includes approximately $105 million pursuant to the Georgia Power Tax Reform Settlement Agreement. Georgia Power's balances also include immaterial amounts related to refunds for transmission service customers. See "Alabama Power" and "Georgia Power – Rate Plans" herein for additional information. (r) Comprised of numerous immaterial components with remaining amortization periods generally not exceeding 17 years for Alabama Power, 12 years for Georgia Power, three years for Mississippi Power, and 20 years for Southern Company Gas at December 31, 2020. (s) Generally not earning a return as they are excluded from rate base or are offset in rate base by a corresponding asset or liability. (t) Fuel-hedging assets and liabilities are recorded over the life of the underlying hedged purchase contracts. Upon final settlement, actual costs incurred are recovered through the applicable traditional electric operating company's fuel cost recovery mechanism. Purchase contracts generally do not exceed three and a half years for Alabama Power, three years for Georgia Power, and five years for Mississippi Power. Immaterial amounts at December 31, 2020 are included in other regulatory assets and liabilities. |
Schedule of revised cost and schedule | Georgia Power's approximate proportionate share of the remaining estimated capital cost to complete Plant Vogtle Units 3 and 4 by the expected in-service dates of November 2021 and November 2022, respectively, is as follows: (in billions) Base project capital cost forecast (a)(b) $ 8.5 Construction contingency estimate 0.2 Total project capital cost forecast (a)(b) 8.7 Net investment as of December 31, 2020 (b) (7.2) Remaining estimate to complete (a) $ 1.5 (a) Excludes financing costs expected to be capitalized through AFUDC of approximately $246 million, of which $93 million had been accrued through December 31, 2020. (b) Net of $1.7 billion received from Toshiba under the Guarantee Settlement Agreement and approximately $188 million in related customer refunds. |
Public utilities general disclosures | In December 2019, the Georgia PSC voted to approve the 2019 ARP, under which Georgia Power increased its rates on January 1, 2020. On December 15, 2020, the Georgia PSC approved tariff adjustments effective January 1, 2021. Details of tariff adjustments are provided in the table below: Tariff 2020 2021 (in millions) Traditional base $ — $ 120 ECCR (*) 318 2 DSM 12 (15) MFF 12 4 Total $ 342 $ 111 (*) Effective January 1, 2020, CCR AROs are being recovered through the ECCR tariff. The following table provides regulatory information for Southern Company Gas' natural gas distribution utilities: Nicor Gas Atlanta Gas Light Virginia Natural Gas Chattanooga Gas Authorized ROE (a) 9.73% 10.25% 9.50% 9.80% Weather normalization mechanisms (b) ü ü Decoupled, including straight-fixed-variable rates (c) ü ü ü Regulatory infrastructure program rates (d) ü ü Bad debt rider (e) ü ü ü Energy efficiency plan (f) ü ü Annual base rate adjustment mechanism (g) ü ü Year of last base rate case decision 2019 2019 2017 2018 (a) Represents the authorized ROE, or the mid-point of the authorized ROE range, at December 31, 2020. (b) Designed to help stabilize operating results by allowing recovery of costs in the event of unseasonal weather, but are not direct offsets to the potential impacts on earnings of weather and customer consumption. (c) Allows for recovery of fixed customer service costs separately from assumed natural gas volumes used by customers and provides a benchmark level of revenue for recovery. (d) Programs that update or expand distribution systems and LNG facilities. (e) The recovery (refund) of bad debt expense over (under) an established benchmark expense. The gas portion of bad debt expense is recovered through purchased gas adjustment mechanisms. Nicor Gas also has a rider to recover the non-gas portion of bad debt expense. (f) Recovery of costs associated with plans to achieve specified energy savings goals. (g) Regulatory mechanism allowing annual adjustments to base rates up or down based on authorized ROE and/or ROE range. The following table and discussions provide updates on the infrastructure replacement programs and capital projects at the natural gas distribution utilities at December 31, 2020. These programs are risk-based and designed to update and replace cast iron, bare steel, and mid-vintage plastic materials or expand Southern Company Gas' distribution systems to improve reliability and meet operational flexibility and growth. Utility Program Recovery Expenditures in 2020 Expenditures Since Project Inception Pipe Scope of Program Duration Last (in millions) (miles) (miles) (years) Nicor Gas Investing in Illinois (*) Rider $ 389 $ 2,101 996 1,450 9 2023 Virginia Natural Gas Steps to Advance Virginia's Energy (SAVE) Rider 49 293 413 770 13 2024 Total $ 438 $ 2,394 1,409 2,220 |
CONTINGENCIES, COMMITMENTS, A_2
CONTINGENCIES, COMMITMENTS, AND GUARANTEES (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Commitments and Contingencies Disclosure [Abstract] | |
Schedule of regulatory assets and liabilities | At December 31, 2020 and 2019, the environmental remediation liability and the balance of under recovered environmental remediation costs were reflected in the balance sheets as follows: Southern Company Georgia Southern Company Gas (in millions) December 31, 2020: Environmental remediation liability: Other current liabilities $ 44 $ 15 $ 29 Accrued environmental remediation 216 — 216 Under recovered environmental remediation costs: Other regulatory assets, current $ 46 $ 12 $ 34 Other regulatory assets, deferred 265 29 236 December 31, 2019: Environmental remediation liability: Other current liabilities $ 51 $ 15 $ 36 Accrued environmental remediation 234 — 233 Under recovered environmental remediation costs: Other regulatory assets, current $ 49 $ 12 $ 37 Other regulatory assets, deferred 300 40 260 |
Expected future contractual obligations | Southern Company Gas' expected future contractual obligations for pipeline charges, storage capacity, and gas supply that are not recognized on the balance sheets at December 31, 2020 were as follows: Pipeline Charges, Storage Capacity, and Gas Supply (in millions) 2021 $ 719 2022 529 2023 441 2024 311 2025 285 Thereafter 1,035 Total $ 3,320 |
REVENUE FROM CONTRACTS WITH C_2
REVENUE FROM CONTRACTS WITH CUSTOMERS (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Revenue from Contract with Customer [Abstract] | |
Disaggregation of revenue | The following table disaggregates revenue from contracts with customers for the periods presented: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) 2020 Operating revenues Retail electric revenues Residential $ 6,113 $ 2,377 $ 3,476 $ 260 $ — $ — Commercial 4,699 1,512 2,933 254 — — Industrial 2,775 1,293 1,197 285 — — Other 90 21 60 9 — — Total retail electric revenues 13,677 5,203 7,666 808 — — Natural gas distribution revenues Residential 1,338 — — — — 1,338 Commercial 340 — — — — 340 Transportation 971 — — — — 971 Industrial 30 — — — — 30 Other 209 — — — — 209 Total natural gas distribution revenues 2,888 — — — — 2,888 Wholesale electric revenues PPA energy revenues 735 133 42 9 570 — PPA capacity revenues 454 108 50 3 296 — Non-PPA revenues 210 43 10 311 239 — Total wholesale electric revenues 1,399 284 102 323 1,105 — Other natural gas revenues Wholesale gas services 1,727 — — — — 1,727 Gas marketing services 391 — — — — 391 Other natural gas revenues 33 — — — — 33 Total natural gas revenues 2,151 — — — — 2,151 Other revenues 982 159 447 26 14 — Total revenue from contracts with customers 21,097 5,646 8,215 1,157 1,119 5,039 Other revenue sources (a) 3,764 184 94 15 614 2,881 Other adjustments (b) (4,486) — — — — (4,486) Total operating revenues $ 20,375 $ 5,830 $ 8,309 $ 1,172 $ 1,733 $ 3,434 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) 2019 Operating revenues Retail electric revenues Residential $ 6,164 $ 2,509 $ 3,377 $ 278 $ — $ — Commercial 5,065 1,677 3,097 291 — — Industrial 3,126 1,460 1,360 306 — — Other 90 25 54 11 — — Total retail electric revenues 14,445 5,671 7,888 886 — — Natural gas distribution revenues Residential 1,413 — — — — 1,413 Commercial 389 — — — — 389 Transportation 907 — — — — 907 Industrial 35 — — — — 35 Other 245 — — — — 245 Total natural gas distribution revenues 2,989 — — — — 2,989 Wholesale electric revenues PPA energy revenues 833 145 60 11 648 — PPA capacity revenues 453 102 54 3 322 — Non-PPA revenues 232 81 9 352 238 — Total wholesale electric revenues 1,518 328 123 366 1,208 — Other natural gas revenues Gas pipeline investments 32 — — — — 32 Wholesale gas services 2,095 — — — — 2,095 Gas marketing services 440 — — — — 440 Other natural gas revenues 42 — — — — 42 Total other natural gas revenues 2,609 — — — — 2,609 Other revenues 1,035 153 407 19 12 — Total revenue from contracts with customers 22,596 6,152 8,418 1,271 1,220 5,598 Other revenue sources (a) 4,266 (27) (10) (7) 718 3,637 Other adjustments (b) (5,443) — — — — (5,443) Total operating revenues $ 21,419 $ 6,125 $ 8,408 $ 1,264 $ 1,938 $ 3,792 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) 2018 Operating revenues Retail electric revenues Residential $ 6,586 $ 2,285 $ 3,295 $ 277 $ — $ — Commercial 5,255 1,541 3,025 290 — — Industrial 3,152 1,364 1,321 326 — — Other 94 25 56 9 — — Total retail electric revenues 15,087 5,215 7,697 902 — — Natural gas distribution revenues Residential 1,525 — — — — 1,525 Commercial 436 — — — — 436 Transportation 944 — — — — 944 Industrial 40 — — — — 40 Other 230 — — — — 230 Total natural gas distribution revenues 3,175 — — — — 3,175 Wholesale electric revenues PPA energy revenues 950 158 81 15 727 — PPA capacity revenues 498 101 53 6 394 — Non-PPA revenues 263 119 24 329 230 — Total wholesale electric revenues 1,711 378 158 350 1,351 — Other natural gas revenues Gas pipeline investments 32 — — — — 32 Wholesale gas services 3,083 — — — — 3,083 Gas marketing services 571 — — — — 571 Other natural gas revenues 53 — — — — 53 Total other natural gas revenues 3,739 — — — — 3,739 Other revenues 1,529 210 236 22 13 — Total revenue from contracts with customers 25,241 5,803 8,091 1,274 1,364 6,914 Other revenue sources (a) 5,108 229 329 (9) 841 3,849 Other adjustments (b) (6,854) — — — — (6,854) Total operating revenues $ 23,495 $ 6,032 $ 8,420 $ 1,265 $ 2,205 $ 3,909 (a) Other revenue sources relate to revenues from customers accounted for as derivatives and leases, alternative revenue programs at Southern Company Gas, and cost recovery mechanisms and revenues that meet other scope exceptions for revenues from contracts with customers at the traditional electric operating companies. (b) Other adjustments relate to the cost of Southern Company Gas' energy and risk management activities. Wholesale gas services revenues are presented net of the related costs of those activities on the statement of income. See Note 16 under "Southern Company Gas" for additional information on the components of wholesale gas services' operating revenues. |
Contract with customer, asset and liability | The following table reflects the closing balances of receivables, contract assets, and contract liabilities related to revenues from contracts with customers at December 31, 2020 and 2019: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Accounts Receivables As of December 31, 2020 $ 2,614 $ 632 $ 806 $ 77 $ 112 $ 788 As of December 31, 2019 2,413 586 688 79 97 749 Contract Assets As of December 31, 2020 $ 158 $ 2 $ 71 $ — $ — $ — As of December 31, 2019 117 — 69 — — — Contract Liabilities As of December 31, 2020 $ 61 $ 6 $ 27 $ 1 $ 1 $ 1 As of December 31, 2019 52 10 13 — 1 1 The following table reflects revenue from contracts with customers recognized in 2020 and 2019 included in the contract liability at December 31, 2019 and December 31, 2018, respectively, for the applicable Registrants: Southern Company Alabama Power Georgia Power Southern Power Southern Company Gas (in millions) Revenue Recognized 2020 $ 33 $ 10 $ 8 $ 1 $ 1 2019 30 11 6 11 2 |
Revenue, remaining performance obligation, expected timing of satisfaction | Revenues from contracts with customers related to these performance obligations remaining at December 31, 2020 are expected to be recognized as follows: 2021 2022 2023 2024 2025 Thereafter (in millions) Southern Company $ 547 $ 395 $ 338 $ 326 $ 306 $ 2,634 Alabama Power 33 31 24 7 5 — Georgia Power 75 46 35 24 21 42 Southern Power 285 287 280 296 280 2,610 |
PROPERTY, PLANT, AND EQUIPMEN_2
PROPERTY, PLANT, AND EQUIPMENT (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Property, Plant and Equipment [Abstract] | |
Property, plant and equipment | The Registrants' property, plant, and equipment in service consisted of the following at December 31, 2020 and 2019: At December 31, 2020: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Electric utilities: Generation $ 52,179 $ 16,201 $ 18,675 $ 2,819 $ 13,872 $ — Transmission 12,879 5,033 6,951 856 — — Distribution 20,958 8,248 11,622 1,088 — — General/other 5,072 2,334 2,434 248 32 — Electric utilities' plant in service 91,088 31,816 39,682 5,011 13,904 — Southern Company Gas: Natural gas distribution utilities transportation and distribution 14,610 — — — — 14,610 Storage facilities 1,752 — — — — 1,752 Other 1,249 — — — — 1,249 Southern Company Gas plant in service 17,611 — — — — 17,611 Other plant in service 1,817 — — — — — Total plant in service $ 110,516 $ 31,816 $ 39,682 $ 5,011 $ 13,904 $ 17,611 At December 31, 2019: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Electric utilities: Generation $ 50,329 $ 15,329 $ 18,341 $ 2,786 $ 13,241 $ — Transmission 12,157 4,719 6,590 808 — — Distribution 19,846 7,798 11,024 1,024 — — General/other 4,650 2,177 2,182 239 29 — Electric utilities' plant in service 86,982 30,023 38,137 4,857 13,270 — Southern Company Gas: Natural gas distribution utilities transportation and distribution 13,518 — — — — 13,518 Storage facilities 1,634 — — — — 1,634 Other 1,192 — — — — 1,192 Southern Company Gas plant in service 16,344 — — — — 16,344 Other plant in service 1,788 — — — — — Total plant in service $ 105,114 $ 30,023 $ 38,137 $ 4,857 $ 13,270 $ 16,344 Southern Power Generating Facility Useful life Natural gas Up to 50 years (*) Solar Up to 35 years Wind Up to 30 years (*) Effective January 1, 2020, Southern Power revised the depreciable lives of its natural gas generating facilities from up to 45 years to up to 50 years. This revision resulted in an immaterial decrease in depreciation for 2020. |
Deferred cloud implementation costs | At December 31, 2020, deferred cloud implementation costs, which are generally included in other deferred charges and assets on the Registrants' balance sheets, are as follows: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) At December 31, 2020: Deferred cloud implementation costs $ 162 $ 38 $ 58 $ 7 $ 9 $ 17 |
Composite straight-line rates | Costs for these services from SCS in 2020, 2019, and 2018 were as follows: Alabama Georgia Mississippi Southern Southern Company Gas (in millions) 2020 $ 478 $ 639 $ 149 $ 87 $ 237 2019 527 704 118 90 183 2018 508 653 104 98 194 Mississippi Southern (in millions) 2020 $ 4 $ 8 2019 3 14 2018 15 41 Alabama Georgia Southern Southern Company Gas (in millions) 2020 $ 15 $ 108 $ 29 $ 29 2019 17 99 28 31 2018 8 101 25 32 Georgia Southern (in millions) 2020 $ — $ 26 2019 4 64 2018 21 119 2020 2019 2018 Alabama Power 2.6 % 3.1 % 3.0 % Georgia Power 3.0 % 2.6 % 2.6 % Mississippi Power 3.7 % 3.7 % 4.2 % Southern Company Gas 2.8 % 2.9 % 2.9 % |
Ownership and investment in jointly-owned facilities | At December 31, 2020, the Registrants' percentage ownership and investment (exclusive of nuclear fuel) in jointly-owned facilities in commercial operation were as follows: Facility (Type) Percent Plant in Service Accumulated CWIP (in millions) Alabama Power Greene County (natural gas) Units 1 and 2 60.0 % (a) $ 189 $ 76 $ 2 Plant Miller (coal) Units 1 and 2 91.8 (b) 2,107 650 24 Georgia Power Plant Hatch (nuclear) 50.1 % (c) $ 1,352 $ 624 $ 37 Plant Vogtle (nuclear) Units 1 and 2 45.7 (c) 3,592 2,221 55 Plant Scherer (coal) Units 1 and 2 8.4 (c) 279 98 1 Plant Scherer (coal) Unit 3 75.0 (c) 1,320 520 4 Plant Wansley (coal) 53.5 (c) 1,068 418 10 Rocky Mountain (pumped storage) 25.4 (d) 183 144 1 Mississippi Power Greene County (natural gas) Units 1 and 2 40.0 % (a) $ 122 $ 54 $ 1 Plant Daniel (coal) Units 1 and 2 50.0 (e) 775 238 15 Southern Company Gas Dalton Pipeline (natural gas pipeline) 50.0 % (f) $ 271 $ 15 $ — (a) Jointly owned by Alabama Power and Mississippi Power and operated and maintained by Alabama Power. (b) Jointly owned with PowerSouth and operated and maintained by Alabama Power. (c) Georgia Power owns undivided interests in Plants Hatch, Vogtle Units 1 and 2, Scherer, and Wansley in varying amounts jointly with one or more of the following entities: OPC, MEAG Power, Dalton, Florida Power & Light Company, JEA, and Gulf Power. Georgia Power has been contracted to operate and maintain the plants as agent for the co-owners and is jointly and severally liable for third party claims related to these plants. (d) Jointly owned with OPC, which is the operator of the plant. (e) Jointly owned by Gulf Power and Mississippi Power. In accordance with the operating agreement, Mississippi Power acts as Gulf Power's agent with respect to the operation and maintenance of these units. See Note 3 under "Other Matters – Mississippi Power – Plant Daniel" for information regarding a commitment between Mississippi Power and Gulf Power to seek a restructuring of their 50% undivided ownership interests in Plant Daniel. (f) Jointly owned with The Williams Companies, Inc., the Dalton Pipeline is a 115-mile natural gas pipeline that serves as an extension of the Transcontinental Gas Pipe Line Company, LLC pipeline system into northwest Georgia. Southern Company Gas leases its 50% undivided ownership for approximately $26 million annually through 2042. The lessee is responsible for maintaining the pipeline during the lease term and for providing service to transportation customers under its FERC-regulated tariff. |
ASSET RETIREMENT OBLIGATIONS (T
ASSET RETIREMENT OBLIGATIONS (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Asset Retirement Obligation Disclosure [Abstract] | |
Details of AROs included in the balance sheets | Details of the AROs included in the balance sheets are as follows: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power (*) (in millions) Balance at December 31, 2018 $ 9,394 $ 3,210 $ 5,829 $ 160 $ 84 Liabilities incurred 37 — 35 1 1 Liabilities settled (328) (127) (151) (35) — Accretion 402 145 243 7 4 Cash flow revisions 281 312 (172) 57 — Balance at December 31, 2019 $ 9,786 $ 3,540 $ 5,784 $ 190 $ 89 Liabilities incurred 19 — 10 — 9 Liabilities settled (442) (219) (185) (22) — Accretion 409 152 238 8 4 Cash flow revisions 912 501 418 — (7) Balance at December 31, 2020 $ 10,684 $ 3,974 $ 6,265 $ 176 $ 95 (*) Included in other deferred credits and liabilities on Southern Power's consolidated balance sheets. |
Investment securities in the Funds | Investment securities in the Funds for December 31, 2020 and 2019 were as follows: Southern Company Alabama Georgia (in millions) At December 31, 2020: Equity securities $ 1,339 $ 842 $ 497 Debt securities 851 231 620 Other securities 111 83 28 Total investment securities in the Funds $ 2,301 $ 1,156 $ 1,145 At December 31, 2019: Equity securities $ 1,159 $ 743 $ 416 Debt securities 798 218 580 Other securities 77 60 17 Total investment securities in the Funds $ 2,034 $ 1,021 $ 1,013 |
Fair value increases (decreases) of the Funds | The fair value increases (decreases) of the Funds, including unrealized gains (losses) and reinvested interest and dividends and excluding the Funds' expenses, for 2020, 2019, and 2018 are shown in the table below. Southern Company Alabama Georgia (in millions) Fair value increases (decreases) 2020 $ 280 $ 142 $ 138 2019 344 194 150 2018 (67) (38) (29) Unrealized gains (losses) At December 31, 2020 $ 220 $ 121 $ 99 At December 31, 2019 259 149 110 At December 31, 2018 (183) (96) (87) At December 31, 2020, assets and liabilities measured at fair value on a recurring basis during the period, together with their associated level of the fair value hierarchy, were as follows: Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2020: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Southern Company Assets: Energy-related derivatives (a) $ 401 $ 271 $ 32 $ — $ 704 Interest rate derivatives — 20 — — 20 Foreign currency derivatives — 87 — — 87 Investments in trusts: (b)(c) Domestic equity 862 151 — — 1,013 Foreign equity 85 253 — — 338 U.S. Treasury and government agency securities — 284 — — 284 Municipal bonds — 85 — — 85 Pooled funds – fixed income — 17 — — 17 Corporate bonds 13 386 — — 399 Mortgage and asset backed securities — 83 — — 83 Private equity — — — 76 76 Cash and cash equivalents 1 — — — 1 Other 28 7 — — 35 Cash equivalents 575 9 — — 584 Other investments 9 24 — — 33 Total $ 1,974 $ 1,677 $ 32 $ 76 $ 3,759 Liabilities: Energy-related derivatives (a) $ 389 $ 204 $ 4 $ — $ 597 Foreign currency derivatives — 23 — — 23 Contingent consideration — — 17 — 17 Total $ 389 $ 227 $ 21 $ — $ 637 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2020: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Alabama Power Assets: Energy-related derivatives $ — $ 12 $ — $ — $ 12 Nuclear decommissioning trusts: (b) Domestic equity 543 141 — — 684 Foreign equity 85 73 — — 158 U.S. Treasury and government agency securities — 21 — — 21 Municipal bonds — 1 — — 1 Corporate bonds 13 167 — — 180 Mortgage and asset backed securities — 29 — — 29 Private equity — — — 76 76 Other 7 — — — 7 Cash equivalents 311 9 — — 320 Other investments — 24 — — 24 Total $ 959 $ 477 $ — $ 76 $ 1,512 Liabilities: Energy-related derivatives $ — $ 7 $ — $ — $ 7 Georgia Power Assets: Energy-related derivatives $ — $ 15 $ — $ — $ 15 Nuclear decommissioning trusts: (b)(c) Domestic equity 319 1 — — 320 Foreign equity — 177 — — 177 U.S. Treasury and government agency securities — 263 — — 263 Municipal bonds — 84 — — 84 Corporate bonds — 219 — — 219 Mortgage and asset backed securities — 54 — — 54 Other 21 7 — — 28 Total $ 340 $ 820 $ — $ — $ 1,160 Liabilities: Energy-related derivatives $ — $ 13 $ — $ — $ 13 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2020: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Mississippi Power Assets: Energy-related derivatives $ — $ 9 $ — $ — $ 9 Cash equivalents 21 — — — 21 Total $ 21 $ 9 $ — $ — $ 30 Liabilities: Energy-related derivatives $ — $ 9 $ — $ — $ 9 Southern Power Assets: Energy-related derivatives $ — $ 2 $ — $ — $ 2 Foreign currency derivatives — 87 — — 87 Total $ — $ 89 $ — $ — $ 89 Liabilities: Energy-related derivatives $ — $ 3 $ — $ — $ 3 Foreign currency derivatives — 23 — — 23 Contingent consideration — — 17 — 17 Total $ — $ 26 $ 17 $ — $ 43 Southern Company Gas Assets: Energy-related derivatives (a) $ 401 $ 233 $ 32 $ — $ 666 Non-qualified deferred compensation trusts: Domestic equity — 9 — — 9 Foreign equity — 3 — — 3 Pooled funds - fixed income — 17 — — 17 Cash equivalents 1 — — — 1 Total $ 402 $ 262 $ 32 $ — $ 696 Liabilities: Energy-related derivatives (a)(b) $ 389 $ 172 $ 4 $ — $ 565 (a) Excludes $6 million associated with premiums and certain weather derivatives accounted for based on intrinsic value rather than fair value and cash collateral of $28 million. (b) Excludes receivables related to investment income, pending investment sales, payables related to pending investment purchases, and currencies. See Note 6 under "Nuclear Decommissioning" for additional information. (c) Includes investment securities pledged to creditors and collateral received and excludes payables related to the securities lending program. See Note 6 under "Nuclear Decommissioning" for additional information. At December 31, 2019, assets and liabilities measured at fair value on a recurring basis during the period, together with their associated level of the fair value hierarchy, were as follows: Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2019: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Southern Company Assets: Energy-related derivatives (a) $ 388 $ 267 $ 22 $ — $ 677 Interest rate derivatives — 2 — — 2 Foreign currency derivatives — 16 — — 16 Investments in trusts: (b)(c) Domestic equity 751 135 — — 886 Foreign equity 68 220 — — 288 U.S. Treasury and government agency securities — 307 — — 307 Municipal bonds — 85 — — 85 Pooled funds – fixed income — 17 — — 17 Corporate bonds 23 297 — — 320 Mortgage and asset backed securities — 87 — — 87 Private equity — — — 56 56 Cash and cash equivalents 1 — — — 1 Other 17 5 — — 22 Cash equivalents 1,393 2 — — 1,395 Other investments 9 21 — — 30 Total $ 2,650 $ 1,461 $ 22 $ 56 $ 4,189 Liabilities: Energy-related derivatives (a) $ 442 $ 254 $ 7 $ — $ 703 Interest rate derivatives — 24 — — 24 Foreign currency derivatives — 24 — — 24 Contingent consideration — — 19 — 19 Total $ 442 $ 302 $ 26 $ — $ 770 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2019: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Alabama Power Assets: Energy-related derivatives $ — $ 4 $ — $ — $ 4 Nuclear decommissioning trusts: (b) Domestic equity 488 123 — — 611 Foreign equity 68 64 — — 132 U.S. Treasury and government agency securities — 21 — — 21 Municipal bonds — 1 — — 1 Corporate bonds 23 144 — — 167 Mortgage and asset backed securities — 29 — — 29 Private equity — — — 56 56 Other 3 1 — — 4 Cash equivalents 691 2 — — 693 Other investments — 21 — — 21 Total $ 1,273 $ 410 $ — $ 56 $ 1,739 Liabilities: Energy-related derivatives $ — $ 24 $ — $ — $ 24 Georgia Power Assets: Energy-related derivatives $ — $ 4 $ — $ — $ 4 Nuclear decommissioning trusts: (b)(c) Domestic equity 263 1 — — 264 Foreign equity — 152 — — 152 U.S. Treasury and government agency securities — 286 — — 286 Municipal bonds — 84 — — 84 Corporate bonds — 153 — — 153 Mortgage and asset backed securities — 57 — — 57 Other 13 4 — — 17 Total $ 276 $ 741 $ — $ — $ 1,017 Liabilities: Energy-related derivatives $ — $ 53 $ — $ — $ 53 Interest rate derivatives — 17 — — 17 Total $ — $ 70 $ — $ — $ 70 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2019: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Mississippi Power Assets: Energy-related derivatives $ — $ 1 $ — $ — $ 1 Cash equivalents 281 — — — 281 Total $ 281 $ 1 $ — $ — $ 282 Liabilities: Energy-related derivatives $ — $ 27 $ — $ — $ 27 Southern Power Assets: Energy-related derivatives $ — $ 3 $ — $ — $ 3 Foreign currency derivatives — 16 — — 16 Cash equivalents 113 — — — 113 Total $ 113 $ 19 $ — $ — $ 132 Liabilities: Energy-related derivatives $ — $ 3 $ — $ — $ 3 Foreign currency derivatives — 24 — — 24 Contingent consideration — — 19 — 19 Total $ — $ 27 $ 19 $ — $ 46 Southern Company Gas Assets: Energy-related derivatives (a) $ 388 $ 255 $ 22 $ — $ 665 Interest rate derivatives — 2 — — 2 Non-qualified deferred compensation trusts: Domestic equity — 11 — — 11 Foreign equity — 4 — — 4 Pooled funds - fixed income — 17 — — 17 Cash equivalents 1 — — — 1 Cash equivalents 8 — — — 8 Total $ 397 $ 289 $ 22 $ — $ 708 Liabilities: Energy-related derivatives (a)(b) $ 442 $ 147 $ 7 $ — $ 596 (a) Excludes $4 million associated with premiums and certain weather derivatives accounted for based on intrinsic value rather than fair value and cash collateral of $99 million. (c) Excludes receivables related to investment income, pending investment sales, payables related to pending investment purchases, and currencies. See Note 6 under "Nuclear Decommissioning" for additional information. (d) Includes investment securities pledged to creditors and collateral received and excludes payables related to the securities lending program. See Note 6 under "Nuclear Decommissioning" for additional information. |
Accumulated provisions for the external decommissioning trust funds | At December 31, 2020 and 2019, the accumulated provisions for the external decommissioning trust funds were as follows: 2020 2019 (in millions) Alabama Power Plant Farley $ 1,156 $ 1,021 Georgia Power Plant Hatch $ 716 $ 634 Plant Vogtle Units 1 and 2 429 379 Total $ 1,145 $ 1,013 |
Estimated costs of decommissioning | The estimated costs of decommissioning at December 31, 2020 based on the most current studies, which were each performed in 2018, were as follows: Plant Plant Hatch (*) Plant Vogtle Units 1 and 2 (*) Decommissioning periods: Beginning year 2037 2034 2047 Completion year 2076 2075 2079 (in millions) Site study costs: Radiated structures $ 1,234 $ 734 $ 601 Spent fuel management 387 172 162 Non-radiated structures 99 56 79 Total site study costs $ 1,720 $ 962 $ 842 (*) Based on Georgia Power's ownership interests. |
CONSOLIDATED ENTITIES AND EQU_2
CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Equity Method Investments and Joint Ventures [Abstract] | |
Equity method investments | The carrying amounts of Southern Company Gas' equity method investments at December 31, 2020 and 2019 and related income from those investments for the years ended December 31, 2020, 2019, and 2018 were as follows: Investment Balance 2020 2019 (a) (in millions) SNG (b) $ 1,167 $ 1,137 PennEast Pipeline (c) 91 82 Other 32 32 Total $ 1,290 $ 1,251 (a) Excludes investments in Atlantic Coast Pipeline and Pivotal JAX LNG classified as held for sale at December 31, 2019. See Note 15 under "Assets Held for Sale" for additional information. (b) Increase primarily relates to a capital contribution, partially offset by the continued amortization of deferred tax assets established upon acquisition. (c) See Note 3 under "Other Matters – Southern Company Gas" for additional information. |
Equity method investments related income | Earnings from Equity Method Investments 2020 2019 2018 (in millions) SNG $ 129 $ 141 $ 131 Atlantic Coast Pipeline (a)(b) 3 13 7 PennEast Pipeline (a) 7 6 5 Other (c) 2 (3) 5 Total $ 141 $ 157 $ 148 (a) Earnings primarily result from AFUDC equity recorded by the project entity. (b) On March 24, 2020, Southern Company Gas completed the sale of its interest in Atlantic Coast Pipeline. See Note 15 under "Southern Company Gas" for additional information. (c) In May 2019, Southern Company Gas sold its investment in Triton, a cargo container leasing company that was aggregated into Southern Company Gas' all other segment. On March 24, 2020, Southern Company Gas completed the sale of its interest in Pivotal LNG. See Note 15 under "Southern Company Gas" for additional information. |
FINANCING (Tables)
FINANCING (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Debt Disclosure [Abstract] | |
Summary of long-term debt | Details of long-term debt at December 31, 2020 and 2019 are provided in the following table: At December 31, 2020 Balance Outstanding at Maturity Weighted Average 2020 2019 (in millions) Southern Company Senior notes (a) 2021-2050 3.78% $ 30,850 $ 30,023 Junior subordinated notes 2024-2080 4.30% 7,295 5,295 FFB loans (b) 2021-2044 2.92% 4,618 3,843 Pollution control revenue bonds (c) 2021-2053 1.11% 2,675 2,963 First mortgage bonds (d) 2023-2060 3.71% 1,900 1,575 Other revenue bonds (e) 2021-2040 6.45% 320 320 Debt payable to affiliated trusts (f) 2042 3.33% 206 206 Medium-term notes 2021-2027 7.88% 160 160 Other long-term debt 2021-2023 0.83% 370 145 Finance lease obligations (g) 231 226 Unamortized fair value adjustment 393 430 Unamortized debt premium (discount), net (201) (152) Unamortized debt issuance expenses (237) (247) Total long-term debt 48,580 44,787 Less: Amount due within one year 3,507 2,989 Total long-term debt excluding amount due within one year $ 45,073 $ 41,798 Alabama Power Senior notes 2021-2049 4.03% $ 7,625 $ 7,275 Pollution control revenue bonds (c) 2021-2038 0.53% 1,060 1,060 Debt payable to affiliated trusts (f) 2042 3.33% 206 206 Other long-term debt 2021 1.20% 45 45 Finance lease obligations (g) 5 4 Unamortized debt premium (discount), net (16) (14) Unamortized debt issuance expenses (56) (55) Total long-term debt 8,869 8,521 Less: Amount due within one year 311 251 Total long-term debt excluding amount due within one year $ 8,558 $ 8,270 Georgia Power Senior notes 2021-2050 3.59% $ 6,400 $ 5,850 Junior subordinated notes 2077 5.00% 270 270 FFB loans (b) 2021-2044 2.92% 4,618 3,843 Pollution control revenue bonds (c) 2025-2053 1.47% 1,538 1,821 Other long-term debt 2021 0.65% 125 — Finance lease obligations (g) 145 156 Unamortized debt premium (discount), net (12) (7) Unamortized debt issuance expenses (114) (117) Total long-term debt 12,970 11,816 Less: Amount due within one year 542 1,025 Total long-term debt excluding amount due within one year $ 12,428 $ 10,791 At December 31, 2020 Balance Outstanding at Maturity Weighted Average 2020 2019 (in millions) Mississippi Power Senior notes 2028-2042 4.23% $ 900 $ 1,175 Pollution control revenue bonds (c) 2025-2028 1.86% 76 83 Other revenue bonds (e) 2021-2040 6.45% 320 320 Other long-term debt 2021-2023 1.00% 100 — Finance lease obligations (g) 19 — Unamortized debt premium (discount), net 11 19 Unamortized debt issuance expenses (7) (8) Total long-term debt 1,419 1,589 Less: Amount due within one year 406 281 Total long-term debt excluding amount due within one year $ 1,013 $ 1,308 Southern Power Senior notes (a) 2021-2046 3.96% $ 3,714 $ 4,425 Unamortized debt premium (discount), net (6) (8) Unamortized debt issuance expenses (16) (19) Total long-term debt 3,692 4,398 Less: Amount due within one year 299 824 Total long-term debt excluding amount due within one year $ 3,393 $ 3,574 Southern Company Gas Senior notes 2021-2047 4.01% $ 4,200 $ 3,700 First mortgage bonds (d) 2023-2060 3.71% 1,900 1,575 Medium-term notes 2021-2027 7.88% 160 160 Unamortized fair value adjustment 393 430 Unamortized debt premium (discount), net (27) (20) Total long-term debt 6,626 5,845 Less: Amount due within one year 333 — Total long-term debt excluding amount due within one year $ 6,293 $ 5,845 (a) Includes a fair value gain (loss) of $109 million and $(5) million at December 31, 2020 and 2019, respectively, related to Southern Power's foreign currency hedge on its €1.1 billion senior notes. (b) Secured by a first priority lien on (i) Georgia Power's 45.7% undivided ownership interest in Plant Vogtle Units 3 and 4 (primarily the units under construction, the related real property, and any nuclear fuel loaded in the reactor core) and (ii) Georgia Power's rights and obligations under the principal contracts relating to Plant Vogtle Units 3 and 4. See "DOE Loan Guarantee Borrowings" for additional information. (c) Pollution control revenue bond obligations represent loans to the traditional electric operating companies from public authorities of funds derived from sales by such authorities of revenue bonds issued to finance pollution control and solid waste disposal facilities. In some cases, the pollution control revenue bond obligations represent obligations under installment sales agreements with respect to facilities constructed with the proceeds of revenue bonds issued by public authorities. The traditional electric operating companies are required to make payments sufficient for the authorities to meet principal and interest requirements of such bonds. Proceeds from certain issuances are restricted until qualifying expenditures are incurred. (d) Secured by substantially all of Nicor Gas' properties. (e) At December 31, 2020 and 2019, Mississippi Power had $270 million aggregate principal amount outstanding of Mississippi Business Finance Corporation Taxable Revenue Bonds, 7.13% Series 1999A due October 20, 2021, which are secured by Plant Daniel Units 3 and 4 and certain related personal property. Mississippi Power assumed the obligations in 2011 in connection with its election under its operating lease of Plant Daniel Units 3 and 4 to purchase the assets and recorded the bonds at fair value. At December 31, 2020 and 2019, Mississippi Power also had $50 million of tax-exempt revenue bond obligations outstanding representing loans to Mississippi Power through the Mississippi Business Finance Corporation issued to finance a portion of the costs of constructing the Kemper County energy facility. (f) Alabama Power has formed a wholly-owned trust subsidiary for the purpose of issuing preferred securities. The proceeds of the related equity investments and preferred security sales were loaned back to Alabama Power through the issuance of junior subordinated notes, which constitute substantially all of the assets of this trust. Alabama Power considers that the mechanisms and obligations relating to the preferred securities issued for its benefit, taken together, constitute a full and unconditional guarantee by it of the trust's payment obligations with respect to these securities. See Note 1 under "Variable Interest Entities" for additional information on the accounting treatment for this trust and the related securities. (g) Secured by the underlying lease ROU asset. See Note 9 for additional information. |
Schedule of maturities of long-term debt for the next five years | Maturities of long-term debt for the next five years are as follows: Southern Company (a) Alabama Power Georgia Power (b) Mississippi Power (c) Southern Power (d) Southern Company (in millions) 2021 $ 3,506 $ 311 $ 542 $ 406 $ 300 $ 330 2022 3,707 751 488 16 677 46 2023 3,131 301 889 1 290 400 2024 509 22 491 1 — — 2025 1,191 250 138 12 500 300 (a) Amount for 2022 includes junior subordinated notes totaling $1.725 billion at the parent entity with final maturity dates in 2024 and 2027 (one half in each year); however, in connection with related stock purchase contracts, Southern Company has agreed to remarket the notes in 2022. See "Equity Units" herein for additional information. Also see notes (b), (c), and (d) below. (b) Amounts include principal amortization related to the FFB borrowings; however, the final maturity date is February 20, 2044. See "DOE Loan Guarantee Borrowings" herein for additional information. (c) Amount for 2021 includes $50 million and $25 million of long-term debt with final maturity dates in 2040 and 2023, respectively, that Mississippi Power intends to repay in 2021. (d) Southern Power's 2022 maturity represents euro-denominated debt at the U.S. dollar denominated hedge settlement amount. |
Summary of committed credit arrangements | At December 31, 2020, committed credit arrangements with banks were as follows: Expires Company 2021 2022 2023 2024 Total Unused Due within (in millions) Southern Company parent $ — $ — $ — $ 2,000 $ 2,000 $ 1,999 $ — Alabama Power 3 525 — 800 1,328 1,328 3 Georgia Power — — — 1,750 1,750 1,728 — Mississippi Power — 150 125 — 275 250 — Southern Power (a) — — — 600 600 591 — Southern Company Gas (b) — — — 1,750 1,750 1,745 — SEGCO 30 — — — 30 30 30 Southern Company $ 33 $ 675 $ 125 $ 6,900 $ 7,733 $ 7,671 $ 33 (a) Does not include Southern Power Company's $75 million and $60 million continuing letter of credit facilities for standby letters of credit expiring in 2023, of which $5 million and $11 million, respectively, was unused at December 31, 2020. In December 2020, Southern Power amended its $120 million letter of credit facility, which, among other things, extended the expiration date from 2021 to 2023 and reduced the amount to $75 million. Southern Power's subsidiaries are not parties to its bank credit arrangements or letter of credit facilities. (b) Southern Company Gas, as the parent entity, guarantees the obligations of Southern Company Gas Capital, which is the borrower of $1.25 billion of this arrangement. Southern Company Gas' committed credit arrangement also includes $500 million for which Nicor Gas is the borrower and which is restricted for working capital needs of Nicor Gas. Pursuant to this multi-year credit arrangement, the allocations between Southern Company Gas Capital and Nicor Gas may be adjusted. See "Structural Considerations" herein for additional information. |
Details of short-term borrowings | Details of short-term borrowings for the applicable Registrants were as follows: Notes Payable at December 31, 2020 Notes Payable at December 31, 2019 Amount Weighted Average Amount Weighted Average (in millions) (in millions) Southern Company Commercial paper $ 609 0.3 % $ 1,705 2.1 % Short-term bank debt — — % 350 2.3 % Total $ 609 0.3 % $ 2,055 2.1 % Georgia Power Commercial paper $ 60 0.3 % $ 115 2.1 % Short-term bank debt — — % 250 2.2 % Total $ 60 0.3 % $ 365 2.2 % Mississippi Power Commercial paper $ 25 0.4 % $ — — % Southern Power Commercial paper $ 175 0.3 % $ 449 2.1 % Short-term bank debt — — % 100 2.6 % Total $ 175 0.3 % $ 549 2.2 % Southern Company Gas Commercial paper: Southern Company Gas Capital $ 220 0.3 % $ 372 2.1 % Nicor Gas 104 0.2 % 278 1.8 % Total $ 324 0.2 % $ 650 2.0 % |
Shares used to compute diluted EPS | Shares used to compute diluted EPS were as follows: Average Common Stock Shares 2020 2019 2018 (in millions) As reported shares 1,058 1,046 1,020 Effect of stock-based compensation 7 8 5 Diluted shares 1,065 1,054 1,025 |
Schedule of preferred stock | Information for each outstanding series is in the table below: Preferred Stock Par Value/Stated Capital Per Share Shares Outstanding Redemption 4.92% Preferred Stock $100 80,000 $103.23 4.72% Preferred Stock $100 50,000 $102.18 4.64% Preferred Stock $100 60,000 $103.14 4.60% Preferred Stock $100 100,000 $104.20 4.52% Preferred Stock $100 50,000 $102.93 4.20% Preferred Stock $100 135,115 $105.00 5.00% Class A Preferred Stock $25 10,000,000 $25.00 (*) |
LEASES (Tables)
LEASES (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Leases [Abstract] | |
Major categories of lease obligations | The major categories of lease obligations are as follows: Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) As of December 31, 2020 Electric generating units $ 941 $ 146 $ 1,368 $ — $ — $ — Real estate/land 815 4 53 2 451 61 Communication towers 158 2 3 — — 20 Railcars 42 16 23 3 — — Other 127 7 5 23 — 1 Total $ 2,083 $ 175 $ 1,452 $ 28 $ 451 $ 82 As of December 31, 2019 Electric generating units $ 990 $ 125 $ 1,487 $ — $ — $ — Real estate/land 782 4 54 2 398 74 Communication towers 154 2 3 — — 18 Railcars 51 21 26 3 — — Other 93 8 12 1 — — Total $ 2,070 $ 160 $ 1,582 $ 6 $ 398 $ 92 |
Balance sheet amounts recorded for operating and financing leases | Balance sheet amounts recorded for operating and finance leases are as follows: Southern Company Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) As of December 31, 2020 Operating Leases Operating lease ROU assets, net $ 1,802 $ 151 $ 1,308 $ 9 $ 415 $ 81 Operating lease obligations - current $ 241 $ 51 $ 151 $ 2 $ 25 $ 15 Operating lease obligations - non-current 1,611 119 1,156 7 426 67 Total operating lease obligations $ 1,852 $ 170 $ 1,307 $ 9 $ 451 $ 82 Finance Leases Finance lease ROU assets, net $ 218 $ 5 $ 115 $ 19 $ — $ — Finance lease obligations - current $ 17 $ 1 $ 9 $ 1 $ — $ — Finance lease obligations - non-current 214 4 136 18 — — Total finance lease obligations $ 231 $ 5 $ 145 $ 19 $ — $ — As of December 31, 2019 Operating Leases Operating lease ROU assets, net $ 1,800 $ 132 $ 1,428 $ 6 $ 369 $ 93 Operating lease obligations - current $ 229 $ 49 $ 144 $ 2 $ 22 $ 14 Operating lease obligations - non-current 1,615 107 1,282 4 376 78 Total operating lease obligations $ 1,844 $ 156 $ 1,426 $ 6 $ 398 $ 92 Finance Leases Finance lease ROU assets, net $ 216 $ 4 $ 130 $ — $ — $ — Finance lease obligations - current $ 21 $ 1 $ 11 $ — $ — $ — Finance lease obligations - non-current 205 3 145 — — — Total finance lease obligations $ 226 $ 4 $ 156 $ — $ — $ — |
Lease costs and other information | Lease costs for 2020 and 2019, which includes both amounts recognized as operations and maintenance expense and amounts capitalized as part of the cost of another asset, are as follows: Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) 2020 Lease cost Operating lease cost $ 309 $ 55 $ 212 $ 3 $ 29 $ 19 Finance lease cost: Amortization of ROU assets 26 1 15 — — — Interest on lease obligations 11 — 16 — — — Total finance lease cost 37 1 31 — — — Short-term lease costs 39 11 26 — — — Variable lease cost 91 4 76 — 7 — Sublease income — (1) — — — — Total lease cost $ 476 $ 70 $ 345 $ 3 $ 36 $ 19 2019 Lease cost Operating lease cost $ 310 $ 54 $ 206 $ 3 $ 28 $ 18 Finance lease cost: Amortization of ROU assets 28 1 15 — — — Interest on lease obligations 12 — 18 — — — Total finance lease cost 40 1 33 — — — Short-term lease costs 48 19 22 — — — Variable lease cost 105 6 85 — 7 — Sublease income — (1) — — — — Total lease cost $ 503 $ 79 $ 346 $ 3 $ 35 $ 18 Rent expense and PPA capacity expense related to leases for 2018, prior to the adoption of ASC 842, were as follows: Southern Company (a)(b)(c) Alabama Georgia (a) Mississippi (b) Southern Power (c) Southern Company Gas (in millions) 2018: Rent expense $ 192 $ 23 $ 34 $ 4 $ 31 $ 15 PPA capacity expense 231 44 206 — — — (a) Georgia Power's energy-only solar PPAs accounted for as leases contained contingent rent expense of $72 million, of which $29 million related to solar PPAs with Southern Power. (b) Mississippi Power's energy-only solar PPAs accounted for as operating leases contained contingent rent expense of $10 million. (c) Rent expense includes contingent rent expense related to Southern Power's land leases based on wind production and escalation in the Consumer Price Index for All Urban Consumers. Other information with respect to cash and noncash activities related to leases, as well as weighted-average lease terms and discount rates, is as follows: Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) 2020 Other information Cash paid for amounts included in the measurements of lease obligations: Operating cash flows from operating leases $ 310 $ 55 $ 215 $ 3 $ 28 $ 18 Operating cash flows from finance leases 9 — 18 — — — Financing cash flows from finance leases 22 1 11 — — — ROU assets obtained in exchange for new operating lease obligations 227 63 32 — 51 4 ROU assets obtained in exchange for new finance lease obligations 10 2 — — — — 2019 Other information Cash paid for amounts included in the measurements of lease obligations: Operating cash flows from operating leases $ 323 $ 54 $ 210 $ 3 $ 27 $ 18 Operating cash flows from finance leases 10 — 19 — — — Financing cash flows from finance leases 32 1 13 — — — ROU assets obtained in exchange for new operating lease obligations 118 7 21 — 2 19 ROU assets obtained in exchange for new finance lease obligations 35 2 24 — — — Southern Alabama Georgia Mississippi Southern Power Southern Company Gas As of December 31, 2020 Weighted-average remaining lease term in years: Operating leases 14.5 7.8 9.4 6.5 32.1 9.8 Finance leases 18.2 9.7 9.5 14.9 N/A N/A Weighted-average discount rate: Operating leases 4.44 % 4.14 % 4.37 % 3.26 % 5.45 % 3.67 % Finance leases 4.79 % 3.20 % 10.81 % 2.74 % N/A N/A As of December 31, 2019 Weighted-average remaining lease term in years: Operating leases 14.2 3.1 10.2 7.0 32.8 9.9 Finance leases 18.8 12.1 10.5 N/A N/A N/A Weighted-average discount rate: Operating leases 4.53 % 3.33 % 4.46 % 4.02 % 5.66 % 3.7 % Finance leases 5.04 % 3.60 % 10.76 % N/A N/A N/A |
Maturities of operating lease liabilities | Maturities of lease liabilities are as follows: As of December 31, 2020 Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Maturity Analysis Operating leases: 2021 $ 300 $ 57 $ 205 $ 2 $ 30 $ 18 2022 287 58 202 4 25 14 2023 230 9 200 1 27 12 2024 187 6 164 1 27 11 2025 165 6 137 — 27 10 Thereafter 1,546 74 701 2 873 35 Total 2,715 210 1,609 10 1,009 100 Less: Present value discount 863 40 302 1 558 18 Operating lease obligations $ 1,852 $ 170 $ 1,307 $ 9 $ 451 $ 82 Finance leases: 2021 $ 28 $ 1 $ 24 $ 2 $ — $ — 2022 25 1 25 1 — — 2023 22 1 25 2 — — 2024 19 1 25 1 — — 2025 16 — 25 2 — — Thereafter 246 1 109 15 — — Total 356 5 233 23 — — Less: Present value discount 125 — 88 4 — — Finance lease obligations $ 231 $ 5 $ 145 $ 19 $ — $ — |
Maturities of finance lease liabilities | Maturities of lease liabilities are as follows: As of December 31, 2020 Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Maturity Analysis Operating leases: 2021 $ 300 $ 57 $ 205 $ 2 $ 30 $ 18 2022 287 58 202 4 25 14 2023 230 9 200 1 27 12 2024 187 6 164 1 27 11 2025 165 6 137 — 27 10 Thereafter 1,546 74 701 2 873 35 Total 2,715 210 1,609 10 1,009 100 Less: Present value discount 863 40 302 1 558 18 Operating lease obligations $ 1,852 $ 170 $ 1,307 $ 9 $ 451 $ 82 Finance leases: 2021 $ 28 $ 1 $ 24 $ 2 $ — $ — 2022 25 1 25 1 — — 2023 22 1 25 2 — — 2024 19 1 25 1 — — 2025 16 — 25 2 — — Thereafter 246 1 109 15 — — Total 356 5 233 23 — — Less: Present value discount 125 — 88 4 — — Finance lease obligations $ 231 $ 5 $ 145 $ 19 $ — $ — |
Leases not yet commenced | As of December 31, 2020, Southern Power has additional leases that have not yet commenced, as detailed in the following table: Southern Lease category Land Expected commencement date 2021 Longest lease term expiration 30 years Estimated total obligations (in millions) $12 |
Lease income, operating leases | Lease income for 2020 and 2019 is as follows: Southern Alabama Power Georgia Power Mississippi Southern Power Southern Company Gas (in millions) 2020 Lease income - interest income on sales-type leases $ 16 $ — $ — $ 12 $ — $ — Lease income - operating leases 208 45 58 2 87 35 Variable lease income 419 — — — 449 — Total lease income $ 643 $ 45 $ 58 $ 14 $ 536 $ 35 2019 Lease income - interest income on sales-type leases $ 9 $ — $ — $ 9 $ — $ — Lease income - operating leases 273 24 71 — 160 35 Variable lease income 403 — — — 434 — Total lease income $ 685 $ 24 $ 71 $ 9 $ 594 $ 35 |
Lease income, sales-type leases | Lease income for 2020 and 2019 is as follows: Southern Alabama Power Georgia Power Mississippi Southern Power Southern Company Gas (in millions) 2020 Lease income - interest income on sales-type leases $ 16 $ — $ — $ 12 $ — $ — Lease income - operating leases 208 45 58 2 87 35 Variable lease income 419 — — — 449 — Total lease income $ 643 $ 45 $ 58 $ 14 $ 536 $ 35 2019 Lease income - interest income on sales-type leases $ 9 $ — $ — $ 9 $ — $ — Lease income - operating leases 273 24 71 — 160 35 Variable lease income 403 — — — 434 — Total lease income $ 685 $ 24 $ 71 $ 9 $ 594 $ 35 |
Undiscounted cash flows to be received under tolling arrangements accounted for as sales-type leases | The undiscounted cash flows to be received by Mississippi Power for in-service leased assets under the lease are as follows: At December 31, 2020 (in millions) 2021 $ 20 2022 19 2023 19 2024 18 2025 17 Thereafter 162 Total undiscounted cash flows $ 255 Lease receivable (*) 138 Difference between undiscounted cash flows and discounted cash flows $ 117 (*) Included in other current assets and other property and investments on the balance sheets. |
Undiscounted cash flows to be received under PPAs accounted for as operating leases | The undiscounted cash flows to be received under operating leases and contracts accounted for as operating leases (adjusted for intercompany eliminations) are as follows: At December 31, 2020 Southern Alabama Georgia Power Southern Southern Company Gas (in millions) 2021 $ 207 $ 83 $ 19 $ 86 $ 35 2022 187 76 8 87 35 2023 138 32 2 88 34 2024 106 4 — 90 33 2025 99 3 — 74 28 Thereafter 978 23 — 313 435 Total $ 1,715 $ 221 $ 29 $ 738 $ 600 |
INCOME TAXES (Tables)
INCOME TAXES (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Income Tax Disclosure [Abstract] | |
Details of income tax provisions | Details of income tax provisions are as follows: 2020 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Federal — Current $ 199 $ 198 $ 365 $ 18 $ (303) $ 82 Deferred 70 44 (224) (14) 299 53 269 242 141 4 (4) 135 State — Current 100 61 60 — (4) 35 Deferred 24 34 (49) 10 11 3 124 95 11 10 7 38 Total $ 393 $ 337 $ 152 $ 14 $ 3 $ 173 2019 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Federal — Current $ 156 $ 61 $ 264 $ (6) $ (717) $ (120) Deferred 1,237 125 180 26 647 195 1,393 186 444 20 (70) 75 State — Current 275 12 6 (1) 1 37 Deferred 130 72 22 11 13 18 405 84 28 10 14 55 Total $ 1,798 $ 270 $ 472 $ 30 $ (56) $ 130 2018 Southern Company Alabama Power Georgia Mississippi Southern Power Southern Company Gas (in millions) Federal — Current $ 167 $ 91 $ 393 $ (567) $ 85 $ 334 Deferred 231 123 (249) 575 (154) 33 398 214 144 8 (69) 367 State — Current 188 26 81 (10) (9) 131 Deferred (137) 51 (11) (100) (86) (34) 51 77 70 (110) (95) 97 Total $ 449 $ 291 $ 214 $ (102) $ (164) $ 464 |
Summary of amortization of tax credits | ITCs amortized in 2020, 2019, and 2018 were immaterial for the traditional electric operating companies and Southern Company Gas and were as follows for Southern Company and Southern Power: Southern Company Southern Power (in millions) 2020 $ 84 $ 59 2019 181 151 2018 87 58 |
Schedule of effective income tax reconciliation | A reconciliation of the federal statutory income tax rate to the effective income tax rate is as follows: 2020 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas Federal statutory rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % State income tax, net of federal deduction 2.8 5.0 0.5 4.8 2.7 4.0 Employee stock plans' dividend deduction (0.7) — — — — — Non-deductible book depreciation 0.7 0.6 0.8 0.5 — — Flowback of excess deferred income taxes (8.8) (3.1) (12.0) (18.5) — (2.7) AFUDC-Equity (0.8) (0.6) (1.1) (0.1) — — Federal PTCs — — — — (2.5) — Amortization of ITC (1.6) (0.1) (0.1) (0.1) (22.1) (0.1) Noncontrolling interests — — — — 3.1 — Leveraged lease impairments (1.6) — — — — — Other 0.2 (0.3) (0.3) 0.9 (0.9) 0.5 Effective income tax (benefit) rate 11.2 % 22.5 % 8.8 % 8.5 % 1.3 % 22.7 % 2019 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas Federal statutory rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % State income tax, net of federal deduction 4.9 4.9 1.0 4.3 4.0 6.1 Employee stock plans' dividend deduction (0.4) — — — — — Non-deductible book depreciation 0.3 0.6 0.5 0.4 — — Flowback of excess deferred income taxes (2.1) (5.3) — (12.6) — (6.0) AFUDC-Equity (0.4) (0.8) (0.6) (0.1) — — ITC basis difference (0.1) — — — (1.9) — Amortization of ITC (0.8) (0.1) (0.1) (0.1) (16.1) (0.1) Tax impact from sale of subsidiaries 5.1 — — — (27.6) (1.4) Noncontrolling interests — — — — 0.8 — Other — (0.4) (0.3) 4.9 (0.6) (1.4) Effective income tax (benefit) rate 27.5 % 19.9 % 21.5 % 17.8 % (20.4) % 18.2 % 2018 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas Federal statutory rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % State income tax, net of federal deduction 1.8 5.0 5.5 (65.1) (90.8) 9.2 Employee stock plans' dividend deduction (1.0) — — — — — Non-deductible book depreciation 0.8 0.6 1.2 0.7 — — Flowback of excess deferred income taxes (4.0) (1.8) — (4.1) — (3.0) AFUDC-Equity (1.0) (1.0) (1.4) — — — ITC basis difference (0.6) — — — (0.2) — Federal PTCs (4.7) — — — (156.6) — Amortization of ITC (2.0) (0.1) (0.2) (0.2) (55.4) (0.1) Tax impact from sale of subsidiaries 8.6 — — — — 28.5 Tax Reform Legislation (1.4) — (4.9) (26.3) 96.1 (0.4) Noncontrolling interests (0.4) — — — (14.9) — Other (0.8) (0.1) 0.1 (1.4) 2.0 0.3 Effective income tax (benefit) rate 16.3 % 23.6 % 21.3 % (75.4) % (198.8) % 55.5 % |
Tax effects between the carrying amounts of assets and liabilities | The tax effects of temporary differences between the carrying amounts of assets and liabilities in the financial statements of the Registrants and their respective tax bases, which give rise to deferred tax assets and liabilities, are as follows: December 31, 2020 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Deferred tax liabilities — Accelerated depreciation $ 8,950 $ 2,453 $ 3,228 $ 319 $ 1,389 $ 1,349 Property basis differences 1,999 1,010 689 148 — 135 Federal effect of net state deferred tax assets — — — 25 — — Leveraged lease basis differences 142 — — — — — Employee benefit obligations 739 250 362 39 12 26 Premium on reacquired debt 78 12 66 — — — Regulatory assets – Storm damage reserves 80 — 80 — — — Employee benefit obligations 1,313 348 438 62 — 45 Remaining book value of retired assets 270 123 141 6 — — AROs 1,969 764 1,165 40 — — AROs 804 328 429 — — — Other 437 128 82 66 12 138 Total deferred income tax liabilities 16,781 5,416 6,680 705 1,413 1,693 Deferred tax assets — Federal effect of net state deferred tax liabilities 284 151 59 — 26 70 State effect of federal deferred taxes 126 126 — — — — Employee benefit obligations 1,511 369 522 80 6 100 Other property basis differences 223 — 72 — 134 — ITC and PTC carryforward 1,853 12 539 — 1,110 — Long-term debt fair value adjustment 86 — — — — 86 Other partnership basis difference 166 — — — 166 — Other comprehensive losses 128 7 17 — 25 — AROs 2,773 1,092 1,594 40 — — Estimated loss on plants under construction 369 — 369 — — — Other deferred state tax attributes 357 — 9 250 68 10 Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) 338 243 76 19 — — Other 660 143 186 39 52 166 Total deferred income tax assets 8,874 2,143 3,443 428 1,587 432 Valuation allowance (136) — (35) (41) (35) (4) Net deferred income tax assets 8,738 2,143 3,408 387 1,552 428 Net deferred income taxes (assets)/liabilities $ 8,043 $ 3,273 $ 3,272 $ 318 $ (139) $ 1,265 Recognized in the balance sheets: Accumulated deferred income taxes – assets $ (132) $ — $ — $ (129) $ (262) $ — Accumulated deferred income taxes – liabilities $ 8,175 $ 3,273 $ 3,272 $ 447 $ 123 $ 1,265 December 31, 2019 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Deferred tax liabilities — Accelerated depreciation $ 8,711 $ 2,402 $ 3,058 $ 315 $ 1,422 $ 1,288 Property basis differences 1,843 912 643 143 — 133 Federal effect of net state deferred tax assets — — — 24 — — Leveraged lease basis differences 236 — — — — — Employee benefit obligations 704 242 351 38 12 12 Premium on reacquired debt 83 13 70 — — — Regulatory assets – Storm damage reserves 109 — 109 — — — Employee benefit obligations 1,174 311 403 55 — 45 Remaining book value of retired assets 341 174 159 8 — — AROs 1,723 613 1,066 44 — — AROs 814 360 405 — — — Other 523 134 81 68 11 198 Total deferred income tax liabilities 16,261 5,161 6,345 695 1,445 1,676 Deferred tax assets — Federal effect of net state deferred tax liabilities 277 162 63 — 24 56 Employee benefit obligations 1,385 334 488 72 5 111 Other property basis differences 230 — 65 — 146 — ITC and PTC carryforward 2,098 11 435 — 1,445 — Long-term debt fair value adjustment 97 — — — — 97 Other partnership basis difference 169 — — — 169 — Other comprehensive losses 112 8 18 — 10 — AROs 2,537 973 1,471 44 — — Estimated loss on plants under construction 283 — 283 — — — Other deferred state tax attributes 402 — 13 251 72 8 Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) 401 240 133 28 — — Other 689 173 154 56 46 190 Total deferred income tax assets 8,680 1,901 3,123 451 1,917 462 Valuation allowance (137) — (35) (41) (36) (5) Net deferred income tax assets 8,543 1,901 3,088 410 1,881 457 Net deferred income taxes (assets)/liabilities $ 7,718 $ 3,260 $ 3,257 $ 285 $ (436) $ 1,219 Recognized in the balance sheets: Accumulated deferred income taxes – assets $ (170) $ — $ — $ (139) $ (551) $ — Accumulated deferred income taxes – liabilities $ 7,888 $ 3,260 $ 3,257 $ 424 $ 115 $ 1,219 |
Summary of tax credit carryforwards | Federal ITC/PTC carryforwards at December 31, 2020 were as follows: Southern Company Alabama Georgia Southern (in millions) Federal ITC/PTC carryforwards $ 1,428 $ 12 $ 114 $ 1,110 Tax Year in which federal ITC/PTC carryforwards begin expiring 2031 2032 2031 2035 Year by which federal ITC/PTC carryforwards are expected to be utilized 2024 2023 2023 2024 |
Summary of operating loss carryforward | At December 31, 2020, the net state income tax benefit of state and local NOL carryforwards for Southern Company's subsidiaries were as follows: Company/Jurisdiction Approximate Net State Income Tax Benefit of NOL Carryforwards Tax Year NOL Mississippi Power Mississippi $ 200 2031 Southern Power Oklahoma 39 2035 Florida 11 2034 South Carolina 2 2036 Other states 1 Various Southern Power Total $ 53 Other (*) New York 11 2035 New York City 14 2035 Other states 21 Various Southern Company Total $ 299 (*) Represents other Southern Company subsidiaries. Alabama Power, Georgia Power, and Southern Company Gas did not have material state or local NOL carryforwards at December 31, 2020. |
Changes in unrecognized tax benefits | Southern Company (in millions) Unrecognized tax benefits at December 31, 2017 $ 18 Tax position changes – decrease from prior periods (18) Unrecognized tax benefits at December 31, 2018 and 2019 $ — Tax positions changes – increase from prior periods 44 Unrecognized tax benefits at December 31, 2020 $ 44 |
RETIREMENT BENEFITS (Tables)
RETIREMENT BENEFITS (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Retirement Benefits [Abstract] | |
Summary of actuarial assumptions | The weighted average rates assumed in the actuarial calculations used to determine both the net periodic costs for the pension and other postretirement benefit plans for the following year and the benefit obligations as of the measurement date are presented below. 2020 Assumptions used to determine net Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas Pension plans Discount rate – benefit obligations 3.41 % 3.44 % 3.40 % 3.41 % 3.52 % 3.39 % Discount rate – interest costs 2.99 3.01 2.96 2.99 3.18 2.99 Discount rate – service costs 3.66 3.69 3.67 3.67 3.70 3.53 Expected long-term return on plan assets 8.25 8.25 8.25 8.25 8.25 8.25 Annual salary increase 4.73 4.73 4.73 4.73 4.73 4.73 Other postretirement benefit plans Discount rate – benefit obligations 3.24 % 3.28 % 3.22 % 3.22 % 3.39 % 3.19 % Discount rate – interest costs 2.80 2.84 2.79 2.76 2.97 2.71 Discount rate – service costs 3.57 3.61 3.57 3.57 3.57 3.52 Expected long-term return on plan assets 7.25 7.36 7.05 7.07 — 6.69 Annual salary increase 4.73 4.73 4.73 4.73 4.73 4.73 2019 Assumptions used to determine net Southern Company Alabama Georgia Mississippi Power Southern Power Southern Company Gas Pension plans Discount rate – benefit obligations 4.49 % 4.51 % 4.48 % 4.49 % 4.65 % 4.47 % Discount rate – interest costs 4.12 4.14 4.10 4.12 4.35 4.11 Discount rate – service costs 4.70 4.73 4.72 4.73 4.75 4.57 Expected long-term return on plan assets 7.75 7.75 7.75 7.75 7.75 7.75 Annual salary increase 4.34 4.46 4.46 4.46 4.46 3.07 Other postretirement benefit plans Discount rate – benefit obligations 4.37 % 4.40 % 4.36 % 4.35 % 4.50 % 4.32 % Discount rate – interest costs 3.98 4.01 3.97 3.95 4.14 3.91 Discount rate – service costs 4.63 4.67 4.64 4.64 4.65 4.56 Expected long-term return on plan assets 6.86 6.76 6.85 6.79 — 6.49 Annual salary increase 4.34 4.46 4.46 4.46 4.46 3.07 2018 Assumptions used to determine net periodic costs: Southern Company Alabama Georgia Mississippi Power Southern Power Southern Company Gas Pension plans Discount rate – benefit obligations 3.80 % 3.81 % 3.79 % 3.80 % 3.94 % 3.74 % Discount rate – interest costs 3.45 3.45 3.42 3.46 3.69 3.41 Discount rate – service costs 3.98 4.00 3.99 3.99 4.01 3.84 Expected long-term return on plan assets 7.95 7.95 7.95 7.95 7.95 7.95 Annual salary increase 4.34 4.46 4.46 4.46 4.46 3.07 Other postretirement benefit plans Discount rate – benefit obligations 3.68 % 3.71 % 3.68 % 3.68 % 3.81 % 3.62 % Discount rate – interest costs 3.29 3.31 3.29 3.29 3.47 3.21 Discount rate – service costs 3.91 3.93 3.91 3.91 3.93 3.82 Expected long-term return on plan assets 6.83 6.83 6.80 6.99 — 5.89 Annual salary increase 4.34 4.46 4.46 4.46 4.46 3.07 2020 Assumptions used to determine benefit obligations: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas Pension plans Discount rate 2.81 % 2.85 % 2.79 % 2.80 % 2.99 % 2.75 % Annual salary increase 4.80 4.80 4.80 4.80 4.80 4.80 Other postretirement benefit plans Discount rate 2.56 % 2.63 % 2.52 % 2.53 % 2.78 % 2.46 % Annual salary increase 4.80 4.80 4.80 4.80 4.80 4.80 2019 Assumptions used to determine benefit obligations: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas Pension plans Discount rate 3.41 % 3.44 % 3.40 % 3.41 % 3.52 % 3.39 % Annual salary increase 4.73 4.73 4.73 4.73 4.73 4.73 Other postretirement benefit plans Discount rate 3.24 % 3.28 % 3.22 % 3.22 % 3.39 % 3.19 % Annual salary increase 4.73 4.73 4.73 4.73 4.73 4.73 |
Schedule of health care cost trend rates | The weighted average medical care cost trend rates used in measuring the APBO for the Registrants at December 31, 2020 were as follows: Initial Cost Trend Rate Ultimate Cost Trend Rate Year That Ultimate Rate is Reached Pre-65 6.00 % 4.50 % 2027 Post-65 medical 5.00 4.50 2027 Post-65 prescription 6.25 4.50 2028 |
Schedule of accumulated and projected benefit obligations | The total accumulated benefit obligation for the pension plans at December 31, 2020 and 2019 was as follows: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) December 31, 2020 $ 14,922 $ 3,414 $ 4,657 $ 683 $ 175 $ 1,072 December 31, 2019 13,391 3,053 4,222 615 151 963 The projected benefit obligations for the qualified and non-qualified pension plans at December 31, 2020 are shown in the following table. All pension plan assets are related to the qualified pension plan. Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Projected benefit obligations: Qualified pension plan $ 15,818 $ 3,719 $ 4,977 $ 718 $ 187 $ 1,114 Non-qualified pension plan 828 135 150 36 30 75 |
Changes in projected benefit obligations and fair value of plan assets | Changes in the projected benefit obligations and the fair value of plan assets during the plan years ended December 31, 2020 and 2019 were as follows: 2020 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Change in benefit obligation Benefit obligation at beginning of year $ 14,788 $ 3,404 $ 4,610 $ 671 $ 185 $ 1,067 Service cost 376 89 96 15 8 33 Interest cost 432 100 133 20 6 31 Benefits paid (629) (132) (202) (27) (6) (69) Actuarial (gain) loss 1,679 393 490 75 24 127 Balance at end of year 16,646 3,854 5,127 754 217 1,189 Change in plan assets Fair value of plan assets at beginning of year 14,057 3,357 4,442 641 169 1,050 Actual return (loss) on plan assets 1,881 450 594 85 22 139 Employer contributions 58 9 10 2 1 3 Benefits paid (629) (132) (202) (27) (6) (69) Fair value of plan assets at end of year 15,367 3,684 4,844 701 186 1,123 Accrued liability $ (1,279) $ (170) $ (283) $ (53) $ (31) $ (66) 2019 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Change in benefit obligation Benefit obligation at beginning of year $ 12,763 $ 2,816 $ 3,905 $ 557 $ 123 $ 907 Dispositions (509) — — — — — Service cost 292 69 74 12 7 25 Interest cost 492 114 156 22 5 36 Benefits paid (596) (125) (194) (26) (4) (64) Actuarial (gain) loss 2,346 530 669 106 54 163 Balance at end of year 14,788 3,404 4,610 671 185 1,067 Change in plan assets Fair value of plan assets at beginning of year 11,611 2,575 3,663 505 123 798 Dispositions (509) — — — — — Actual return (loss) on plan assets 2,343 524 730 103 43 172 Employer contributions 1,208 383 243 59 7 144 Benefits paid (596) (125) (194) (26) (4) (64) Fair value of plan assets at end of year 14,057 3,357 4,442 641 169 1,050 Accrued liability $ (731) $ (47) $ (168) $ (30) $ (16) $ (17) |
Amounts recognized in balance sheets | Amounts recognized in the balance sheets at December 31, 2020 and 2019 related to the Registrants' pension plans consist of the following: Southern Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) December 31, 2020: Other regulatory assets, deferred (*) $ 4,655 $ 1,286 $ 1,598 $ 235 $ — $ 205 Other deferred charges and assets — — — — — 70 Other current liabilities (52) (9) (10) (2) (2) (2) Employee benefit obligations (1,227) (161) (273) (51) (29) (134) Other regulatory liabilities, deferred (34) — — — — — AOCI 245 — — — 60 1 December 31, 2019: Prepaid pension costs $ 2 $ 71 $ — $ 2 $ 10 $ — Other regulatory assets, deferred (*) 4,072 1,130 1,416 204 — 172 Other deferred charges and assets — — — — — 82 Other current liabilities (54) (8) (11) (2) (2) (2) Employee benefit obligations (679) (110) (157) (30) (24) (97) Other regulatory liabilities, deferred (79) — — — — — AOCI 185 — — — 46 (14) (*) Amounts for Southern Company exclude regulatory assets of $224 million and $252 million at December 31, 2020 and 2019, respectively, associated with unamortized amounts in Southern Company Gas' pension plans prior to its acquisition by Southern Company. Presented below are the amounts included in regulatory assets at December 31, 2020 and 2019 related to the portion of the defined benefit pension plan attributable to Southern Company, the traditional electric operating companies, and Southern Company Gas that had not yet been recognized in net periodic pension cost. Southern Alabama Power Georgia Mississippi Power Southern Company Gas (in millions) Balance at December 31, 2020 Regulatory assets: Prior service cost $ 11 $ 5 $ 9 $ 2 $ (13) Net (gain) loss 4,610 1,281 1,589 233 135 Regulatory amortization — — — — 83 Total regulatory assets (*) $ 4,621 $ 1,286 $ 1,598 $ 235 $ 205 Balance at December 31, 2019 Regulatory assets: Prior service cost $ 13 $ 6 $ 10 $ 2 $ (15) Net (gain) loss 3,980 1,124 1,406 201 113 Regulatory amortization — — — — 74 Total regulatory assets (*) $ 3,993 $ 1,130 $ 1,416 $ 203 $ 172 (*) Amounts for Southern Company exclude regulatory assets of $224 million and $252 million at December 31, 2020 and 2019, respectively, associated with unamortized amounts in Southern Company Gas' pension plans prior to its acquisition by Southern Company. Amounts recognized in the balance sheets at December 31, 2020 and 2019 related to the Registrants' other postretirement benefit plans consist of the following: Southern Company Alabama Power Georgia Mississippi Power Southern Southern Company Gas (in millions) December 31, 2020: Other regulatory assets, deferred (a) $ 137 $ — $ 47 $ 5 $ — $ (23) Other current liabilities (5) — — — — — Employee benefit obligations (b) (785) (5) (272) (54) (12) (120) Other regulatory liabilities, deferred (86) (21) — — — — AOCI 8 — — — 3 — December 31, 2019: Other regulatory assets, deferred (a) $ 183 $ 3 $ 96 $ 10 $ — $ (11) Other current liabilities (5) — — — — — Employee benefit obligations (b) (919) (49) (339) (61) (11) (135) Other regulatory liabilities, deferred (62) (2) — — — — AOCI 2 — — — 2 (4) (a) Amounts for Southern Company exclude regulatory assets of $47 million and $50 million at December 31, 2020 and 2019, respectively, associated with unamortized amounts in Southern Company Gas' other postretirement benefit plans prior to its acquisition by Southern Company. (b) Included in other deferred credits and liabilities on Southern Power's consolidated balance sheets. Presented below are the amounts included in net regulatory assets (liabilities) at December 31, 2020 and 2019 related to the other postretirement benefit plans of Southern Company, the traditional electric operating companies, and Southern Company Gas that had not yet been recognized in net periodic other postretirement benefit cost. Southern Company Alabama Power Georgia Mississippi Power Southern Company Gas (in millions) Balance at December 31, 2020: Regulatory assets (liabilities): Prior service cost $ 12 $ 3 $ 5 $ — $ 1 Net (gain) loss 39 (24) 42 5 (49) Regulatory amortization — — — — 25 Total regulatory assets (liabilities) (*) $ 51 $ (21) $ 47 $ 5 $ (23) Balance at December 31, 2019: Regulatory assets (liabilities): Prior service cost $ 11 $ 3 $ 4 $ — $ 1 Net (gain) loss 110 (2) 92 10 (43) Regulatory amortization — — — — 31 Total regulatory assets (liabilities) (*) $ 121 $ 1 $ 96 $ 10 $ (11) (*) Amounts for Southern Company exclude regulatory assets of $47 million and $50 million at December 31, 2020 and 2019, respectively, associated with unamortized amounts in Southern Company Gas' other postretirement benefit plans prior to its acquisition by Southern Company. |
Changes in balances of regulatory assets and regulatory liabilities related to defined benefit pension plans | The changes in the balance of regulatory assets related to the portion of the defined benefit pension plan attributable to Southern Company, the traditional electric operating companies, and Southern Company Gas for the years ended December 31, 2020 and 2019 are presented in the following table: Southern Alabama Power Georgia Mississippi Power Southern Company Gas (in millions) Regulatory assets (liabilities): (*) Balance at December 31, 2018 $ 3,458 $ 955 $ 1,230 $ 167 $ 160 Net (gain) loss 801 213 231 42 30 Dispositions (144) — — — — Reclassification adjustments: Amortization of prior service costs (3) (1) (1) — 2 Amortization of net gain (loss) (119) (37) (44) (6) — Amortization of regulatory assets (*) — — — — (20) Total reclassification adjustments (122) (38) (45) (6) (18) Total change 535 175 186 36 12 Balance at December 31, 2019 $ 3,993 $ 1,130 $ 1,416 $ 203 $ 172 Net (gain) loss 884 228 269 45 45 Reclassification adjustments: Amortization of prior service costs (1) (1) (1) — 2 Amortization of net gain (loss) (255) (71) (86) (13) (8) Amortization of regulatory assets (*) — — — — (6) Total reclassification adjustments (256) (72) (87) (13) (12) Total change 628 156 182 32 33 Balance at December 31, 2020 $ 4,621 $ 1,286 $ 1,598 $ 235 $ 205 (*) Amounts for Southern Company exclude regulatory assets of $224 million and $252 million at December 31, 2020 and 2019, respectively, associated with unamortized amounts in Southern Company Gas' pension plans prior to its acquisition by Southern Company. The changes in the balance of net regulatory assets (liabilities) related to the other postretirement benefit plans for the plan years ended December 31, 2020 and 2019 are presented in the following table: Southern Company Alabama Power Georgia Mississippi Power Southern Company Gas (in millions) Net regulatory assets (liabilities): (*) Balance at December 31, 2018 $ 22 $ (9) $ 60 $ 4 $ (4) Net (gain) loss 90 14 37 6 (1) Dispositions 5 — — — — Change in prior service costs 5 — — — — Reclassification adjustments: Amortization of prior service costs (3) (4) — — — Amortization of net gain (loss) 2 — (1) — — Amortization of regulatory assets (*) — — — — (6) Total reclassification adjustments (1) (4) (1) — (6) Total change 99 10 36 6 (7) Balance at December 31, 2019 $ 121 $ 1 $ 96 $ 10 $ (11) Net (gain) loss (65) (22) (47) (5) (5) Reclassification adjustments: Amortization of prior service costs 1 — 1 — — Amortization of net gain (loss) (6) — (3) — — Amortization of regulatory assets (*) — — — — (7) Total reclassification adjustments (5) — (2) — (7) Total change (70) (22) (49) (5) (12) Balance at December 31, 2020 $ 51 $ (21) $ 47 $ 5 $ (23) (*) Amounts for Southern Company exclude regulatory assets of $47 million and $50 million at December 31, 2020 and 2019, respectively, associated with unamortized amounts in Southern Company Gas' other postretirement benefit plans prior to its acquisition by Southern Company. |
Amounts included in AOCI related to defined benefit pension plans | Presented below are the amounts included in AOCI at December 31, 2020 and 2019 related to the portion of the defined benefit pension plan attributable to Southern Company, Southern Power, and Southern Company Gas that had not yet been recognized in net periodic pension cost. Southern Southern Southern Company (in millions) Balance at December 31, 2020 AOCI: Prior service cost $ (3) $ — $ (4) Net (gain) loss 248 60 5 Total AOCI $ 245 $ 60 $ 1 Balance at December 31, 2019 AOCI: Prior service cost $ (3) $ — $ (6) Net (gain) loss 188 46 (8) Total AOCI $ 185 $ 46 $ (14) Presented below are the amounts included in AOCI at December 31, 2020 and 2019 related to the other postretirement benefit plans of Southern Company, Southern Power, and Southern Company Gas that had not yet been recognized in net periodic other postretirement benefit cost. Southern Southern Southern Company (in millions) Balance at December 31, 2020 AOCI: Prior service cost $ 1 $ — $ 1 Net (gain) loss 7 3 (1) Total AOCI $ 8 $ 3 $ — Balance at December 31, 2019 AOCI: Prior service cost $ 1 $ — $ 1 Net (gain) loss 1 2 (5) Total AOCI $ 2 $ 2 $ (4) |
Components of OCI related to defined benefit pension plan | The components of OCI related to the portion of the defined benefit pension plan attributable to Southern Company, Southern Power, and Southern Company Gas for the years ended December 31, 2020 and 2019 are presented in the following table: Southern Company Southern Southern Company (in millions) AOCI: Balance at December 31, 2018 $ 97 $ 26 $ (44) Net (gain) loss 88 20 30 Balance at December 31, 2019 $ 185 $ 46 $ (14) Net (gain) loss 74 16 15 Reclassification adjustments: Amortization of prior service costs — — 1 Amortization of net gain (loss) (14) (2) (1) Total reclassification adjustments (14) (2) — Total change 60 14 15 Balance at December 31, 2020 $ 245 $ 60 $ 1 The components of OCI related to the other postretirement benefit plans for the plan years ended December 31, 2020 and 2019 are presented in the following table: Southern Company Southern Southern Company Gas (in millions) AOCI: Balance at December 31, 2018 $ (4) $ 1 $ (4) Net (gain) loss 5 1 — Reclassification adjustments: Amortization of net gain (loss) 1 — — Total change 6 1 — Balance at December 31, 2019 $ 2 $ 2 $ (4) Net (gain) loss 2 1 — Reclassification adjustments: Amortization of net gain (loss) 4 — 4 Total change 6 1 4 Balance at December 31, 2020 $ 8 $ 3 $ — |
Components of net periodic benefit cost | Components of net periodic pension cost for the Registrants were as follows: Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) 2020 Service cost $ 376 $ 89 $ 96 $ 15 $ 8 $ 33 Interest cost 432 100 133 20 6 31 Expected return on plan assets (1,100) (264) (347) (51) (13) (75) Recognized net (gain) loss 269 71 86 13 2 6 Net amortization 1 1 1 — — 15 Prior service cost — — — — — (3) Net periodic pension cost $ (22) $ (3) $ (31) $ (3) $ 3 $ 7 2019 Service cost $ 292 $ 69 $ 74 $ 12 $ 7 $ 25 Interest cost 492 114 156 22 5 36 Expected return on plan assets (885) (206) (292) (40) (10) (60) Recognized net (gain) loss 120 37 44 6 1 2 Net amortization 2 — 1 — — 14 Prior service cost — — — — — (3) Net periodic pension cost $ 21 $ 14 $ (17) $ — $ 3 $ 14 2018 Service cost $ 359 $ 78 $ 87 $ 17 $ 9 $ 34 Interest cost 464 101 139 20 5 39 Expected return on plan assets (943) (207) (296) (41) (10) (75) Recognized net (gain) loss 213 54 69 10 1 12 Net amortization 4 1 2 — — 15 Prior service cost — — — — — (2) Net periodic pension cost $ 97 $ 27 $ 1 $ 6 $ 5 $ 23 Components of the other postretirement benefit plans' net periodic cost for the Registrants were as follows: Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) 2020 Service cost $ 22 $ 6 $ 6 $ 1 $ 1 $ 2 Interest cost 54 13 20 2 — 7 Expected return on plan assets (72) (29) (26) (1) — (10) Net amortization 1 — 2 — — 6 Net periodic postretirement benefit cost $ 5 $ (10) $ 2 $ 2 $ 1 $ 5 2019 Service cost $ 18 $ 5 $ 5 $ 1 $ 1 $ 1 Interest cost 69 16 26 3 — 9 Expected return on plan assets (65) (26) (25) (2) — (7) Net amortization — 4 1 — — 6 Net periodic postretirement benefit cost $ 22 $ (1) $ 7 $ 2 $ 1 $ 9 2018 Service cost $ 24 $ 6 $ 6 $ 1 $ 1 $ 2 Interest cost 75 17 28 3 — 10 Expected return on plan assets (69) (26) (25) (2) — (7) Net amortization 21 5 10 1 — 6 Net periodic postretirement benefit cost $ 51 $ 2 $ 19 $ 3 $ 1 $ 11 |
Estimated pension benefit payments | At December 31, 2020, estimated benefit payments were as follows: Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Benefit Payments: 2021 $ 651 $ 141 $ 208 $ 29 $ 6 $ 66 2022 678 147 215 30 6 66 2023 702 154 222 31 6 66 2024 725 158 229 32 6 65 2025 748 165 235 33 7 65 2026 to 2030 4,024 895 1,244 181 38 330 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Benefit payments: 2021 $ 115 $ 25 $ 42 $ 6 $ — $ 18 2022 113 25 41 5 — 18 2023 111 25 40 5 — 18 2024 110 24 38 4 1 17 2025 113 25 40 5 1 17 2026 to 2030 550 127 199 23 3 76 |
Changes in the APBO and the fair value of plan assets | Changes in the APBO and the fair value of the Registrants' plan assets during the plan years ended December 31, 2020 and 2019 were as follows: 2020 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Change in benefit obligation Benefit obligation at beginning of year $ 1,985 $ 462 $ 742 $ 87 $ 11 $ 250 Service cost 22 6 6 1 1 2 Interest cost 54 13 20 2 — 7 Benefits paid (126) (29) (46) (6) — (17) Actuarial (gain) loss 7 9 (26) (3) — 6 Retiree drug subsidy 6 2 3 — — — Balance at end of year 1,948 463 699 81 12 248 Change in plan assets Fair value of plan assets at beginning of year 1,061 413 403 26 — 115 Actual return (loss) on plan assets 145 60 50 3 — 18 Employer contributions 72 12 17 4 — 12 Benefits paid (120) (27) (43) (6) — (17) Fair value of plan assets at end of year 1,158 458 427 27 — 128 Accrued liability $ (790) $ (5) $ (272) $ (54) $ (12) $ (120) 2019 Southern Company Alabama Power Georgia Mississippi Power Southern Power Southern Company Gas (in millions) Change in benefit obligation Benefit obligation at beginning of year $ 1,865 $ 403 $ 675 $ 81 $ 9 $ 244 Dispositions (69) — — — — — Service cost 18 5 5 1 1 1 Interest cost 69 16 26 3 — 9 Benefits paid (126) (27) (47) (6) (1) (17) Actuarial (gain) loss 223 63 80 8 2 13 Retiree drug subsidy 5 2 3 — — — Balance at end of year 1,985 462 742 87 11 250 Change in plan assets Fair value of plan assets at beginning of year 928 360 344 23 — 98 Dispositions (18) — — — — — Actual return (loss) on plan assets 189 76 68 4 — 21 Employer contributions 83 2 35 5 1 13 Benefits paid (121) (25) (44) (6) (1) (17) Fair value of plan assets at end of year 1,061 413 403 26 — 115 Accrued liability $ (924) $ (49) $ (339) $ (61) $ (11) $ (135) |
Summary of investment strategies and benefit plan asset fair values | A description of the major asset classes that the pension and other postretirement benefit plans are comprised of, along with the valuation methods used for fair value measurement, is provided below: Description Valuation Methodology Domestic equity: A mix of large and small capitalization stocks with generally an equal distribution of value and growth attributes, managed both actively and through passive index approaches. International equity: A mix of large and small capitalization growth and value stocks with developed and emerging markets exposure, managed both actively and through fundamental indexing approaches. Domestic and international equities such as common stocks, American depositary receipts, and real estate investment trusts that trade on public exchanges are classified as Level 1 investments and are valued at the closing price in the active market. Equity funds with unpublished prices that are comprised of publicly traded securities (such as commingled/pooled funds) are also valued at the closing price in the active market, but are classified as Level 2. Fixed income: A mix of domestic and international bonds. Investments in fixed income securities, including fixed income pooled funds, are generally classified as Level 2 investments and are valued based on prices reported in the market place. Additionally, the value of fixed income securities takes into consideration certain items such as broker quotes, spreads, yield curves, interest rates, and discount rates that apply to the term of a specific instrument. Trust-owned life insurance (TOLI): Investments of taxable trusts aimed at minimizing the impact of taxes on the portfolio. Investments in TOLI policies are classified as Level 2 investments and are valued based on the underlying investments held in the policy's separate accounts. The underlying assets are equity and fixed income pooled funds that are comprised of Level 1 and Level 2 securities. Special situations: Investments in opportunistic strategies with the objective of diversifying and enhancing returns and exploiting short-term inefficiencies, as well as investments in promising new strategies of a longer-term nature. Real estate: Investments in traditional private market, equity-oriented investments in real properties (indirectly through pooled funds or partnerships) and in publicly traded real estate securities. Private equity: Investments in private partnerships that invest in private or public securities typically through privately-negotiated and/or structured transactions, including leveraged buyouts, venture capital, and distressed debt. Investments in real estate, private equity, and special situations are generally classified as Net Asset Value as a Practical Expedient, since the underlying assets typically do not have publicly available observable inputs. The fund manager values the assets using various inputs and techniques depending on the nature of the underlying investments. Techniques may include purchase multiples for comparable transactions, comparable public company trading multiples, discounted cash flow analysis, prevailing market capitalization rates, recent sales of comparable investments, and independent third-party appraisals. The fair value of partnerships is determined by aggregating the value of the underlying assets less liabilities. |
Fair values of plan assets | The fair values, and actual allocations relative to the target allocations, of the Southern Company system's pension plans at December 31, 2020 and 2019 are presented below. Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Net Asset Value as a Practical Expedient Target Allocation Actual Allocation At December 31, 2020: (Level 1) (Level 2) (NAV) Total (in millions) Southern Company Assets: Equity: 51 % 56 % Domestic equity $ 2,852 $ 1,247 $ — $ 4,099 International equity 2,660 1,497 — 4,157 Fixed income: 23 23 U.S. Treasury, government, and agency bonds — 951 — 951 Mortgage- and asset-backed securities — 9 — 9 Corporate bonds — 1,673 — 1,673 Pooled funds — 772 — 772 Cash equivalents and other 356 5 — 361 Real estate investments 542 — 1,596 2,138 14 13 Special situations — — 166 166 3 1 Private equity — — 1,104 1,104 9 7 Total $ 6,410 $ 6,154 $ 2,866 $ 15,430 100 % 100 % Alabama Power Assets: Equity: 51 % 56 % Domestic equity $ 685 $ 299 $ — $ 984 International equity 638 359 — 997 Fixed income: 23 23 U.S. Treasury, government, and agency bonds — 228 — 228 Mortgage- and asset-backed securities — 2 — 2 Corporate bonds — 401 — 401 Pooled funds — 185 — 185 Cash equivalents and other 85 1 — 86 Real estate investments 130 — 382 512 14 13 Special situations — — 40 40 3 1 Private equity — — 264 264 9 7 Total $ 1,538 $ 1,475 $ 686 $ 3,699 100 % 100 % Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Net Asset Value as a Practical Expedient Target Allocation Actual Allocation At December 31, 2020: (Level 1) (Level 2) (NAV) Total (in millions) Georgia Power Assets: Equity: 51 % 56 % Domestic equity $ 899 $ 393 $ — $ 1,292 International equity 839 472 — 1,311 Fixed income: 23 23 U.S. Treasury, government, and agency bonds — 300 — 300 Mortgage- and asset-backed securities — 3 — 3 Corporate bonds — 527 — 527 Pooled funds — 243 — 243 Cash equivalents and other 112 1 — 113 Real estate investments 171 — 503 674 14 13 Special situations — — 53 53 3 1 Private equity — — 348 348 9 7 Total $ 2,021 $ 1,939 $ 904 $ 4,864 100 % 100 % Mississippi Power Assets: Equity: 51 % 56 % Domestic equity $ 131 $ 57 $ — $ 188 International equity 122 68 — 190 Fixed income: 23 23 U.S. Treasury, government, and agency bonds — 43 — 43 Corporate bonds — 76 — 76 Pooled funds — 35 — 35 Cash equivalents and other 16 — — 16 Real estate investments 25 — 73 98 14 13 Special situations — — 8 8 3 1 Private equity — — 50 50 9 7 Total $ 294 $ 279 $ 131 $ 704 100 % 100 % Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Net Asset Value as a Practical Expedient Target Allocation Actual Allocation At December 31, 2020: (Level 1) (Level 2) (NAV) Total (in millions) Southern Power Assets: Equity: 51 % 56 % Domestic equity $ 35 $ 15 $ — $ 50 International equity 32 19 — 51 Fixed income: 23 23 U.S. Treasury, government, and agency bonds — 12 — 12 Corporate bonds — 20 — 20 Pooled funds — 9 — 9 Cash equivalents and other 4 — — 4 Real estate investments 7 — 19 26 14 13 Special situations — — 2 2 3 1 Private equity — — 13 13 9 7 Total $ 78 $ 75 $ 34 $ 187 100% 100 % Southern Company Gas Assets: Equity: 51 % 56 % Domestic equity $ 209 $ 91 $ — $ 300 International equity 195 109 — 304 Fixed income: 23 23 U.S. Treasury, government, and agency bonds — 69 — 69 Mortgage- and asset-backed securities — 1 — 1 Corporate bonds — 122 — 122 Pooled funds — 56 — 56 Cash equivalents and other 26 — — 26 Real estate investments 40 — 117 157 14 13 Special situations — — 12 12 3 1 Private equity — — 81 81 9 7 Total $ 470 $ 448 $ 210 $ 1,128 100 % 100 % Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Net Asset Value as a Practical Expedient Target Allocation Actual Allocation At December 31, 2019: (Level 1) (Level 2) (NAV) Total (in millions) Southern Company Assets: Equity: 51 % 51 % Domestic equity $ 2,220 $ 898 $ — $ 3,118 International equity 2,360 1,286 — 3,646 Fixed income: 23 29 U.S. Treasury, government, and agency bonds — 965 — 965 Mortgage- and asset-backed securities — 9 — 9 Corporate bonds — 1,315 — 1,315 Pooled funds — 684 — 684 Cash equivalents and other 1,317 — — 1,317 Real estate investments 539 — 1,418 1,957 14 12 Special situations — — 155 155 3 1 Private equity — — 953 953 9 7 Total $ 6,436 $ 5,157 $ 2,526 $ 14,119 100 % 100 % Alabama Power Assets: Equity: 51 % 51 % Domestic equity $ 530 $ 214 $ — $ 744 International equity 564 307 — 871 Fixed income: 23 29 U.S. Treasury, government, and agency bonds — 230 — 230 Mortgage- and asset-backed securities — 2 — 2 Corporate bonds — 314 — 314 Pooled funds — 163 — 163 Cash equivalents and other 315 — — 315 Real estate investments 129 — 339 468 14 12 Special situations — — 37 37 3 1 Private equity — — 228 228 9 7 Total $ 1,538 $ 1,230 $ 604 $ 3,372 100 % 100 % Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Net Asset Value as a Practical Expedient Target Allocation Actual Allocation At December 31, 2019: (Level 1) (Level 2) (NAV) Total (in millions) Georgia Power Assets: Equity: 51 % 51 % Domestic equity $ 701 $ 284 $ — $ 985 International equity 746 407 — 1,153 Fixed income: 23 29 U.S. Treasury, government, and agency bonds — 305 — 305 Mortgage- and asset-backed securities — 3 — 3 Corporate bonds — 415 — 415 Pooled funds — 216 — 216 Cash equivalents and other 416 — — 416 Real estate investments 170 — 448 618 14 12 Special situations — — 49 49 3 1 Private equity — — 301 301 9 7 Total $ 2,033 $ 1,630 $ 798 $ 4,461 100 % 100 % Mississippi Power Assets: Equity: 51 % 51 % Domestic equity $ 101 $ 41 $ — $ 142 International equity 108 59 — 167 Fixed income: 23 29 U.S. Treasury, government, and agency bonds — 44 — 44 Corporate bonds — 60 — 60 Pooled funds — 31 — 31 Cash equivalents and other 60 — — 60 Real estate investments 25 — 65 90 14 12 Special situations — — 7 7 3 1 Private equity — — 43 43 9 7 Total $ 294 $ 235 $ 115 $ 644 100 % 100 % Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Net Asset Value as a Practical Expedient Target Allocation Actual Allocation At December 31, 2019: (Level 1) (Level 2) (NAV) Total (in millions) Southern Power Assets: Equity: 51 % 51 % Domestic equity $ 27 $ 11 $ — $ 38 International equity 28 16 — 44 Fixed income: 23 29 U.S. Treasury, government, and agency bonds — 12 — 12 Corporate bonds — 16 — 16 Pooled funds — 8 — 8 Cash equivalents and other 16 — — 16 Real estate investments 6 — 17 23 14 12 Special situations — — 2 2 3 1 Private equity — — 11 11 9 7 Total $ 77 $ 63 $ 30 $ 170 100 % 100 % Southern Company Gas Assets: Equity: 51 % 51 % Domestic equity $ 166 $ 67 $ — $ 233 International equity 176 96 — 272 Fixed income: 23 29 U.S. Treasury, government, and agency bonds — 72 — 72 Mortgage- and asset-backed securities — 1 — 1 Corporate bonds — 98 — 98 Pooled funds — 51 — 51 Cash equivalents and other 98 — — 98 Real estate investments 40 — 106 146 14 12 Special situations — — 12 12 3 1 Private equity — — 71 71 9 7 Total $ 480 $ 385 $ 189 $ 1,054 100 % 100 % The fair values, and actual allocations relative to the target allocations, of the applicable Registrants' other postretirement benefit plan assets at December 31, 2020 and 2019 are presented below. Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Net Asset Value as a Practical Expedient Total Target Allocation Actual Allocation At December 31, 2020: (Level 1) (Level 2) (NAV) (in millions) Southern Company Assets: Equity: 63 % 66 % Domestic equity $ 113 $ 98 $ — $ 211 International equity 71 102 — 173 Fixed income: 28 27 U.S. Treasury, government, and agency bonds — 32 — 32 Corporate bonds — 44 — 44 Pooled funds — 86 — 86 Cash equivalents and other 15 — — 15 Trust-owned life insurance — 508 — 508 Real estate investments 15 — 42 57 5 5 Special situations — — 4 4 1 — Private equity — — 29 29 3 2 Total $ 214 $ 870 $ 75 $ 1,159 100 % 100 % Alabama Power Assets: Equity: 68 % 69 % Domestic equity $ 26 $ 11 $ — $ 37 International equity 23 13 — 36 Fixed income: 24 25 U.S. Treasury, government, and agency bonds — 11 — 11 Corporate bonds — 14 — 14 Pooled funds — 7 — 7 Cash equivalents and other 5 — — 5 Trust-owned life insurance — 321 — 321 Real estate investments 5 — 13 18 4 4 Special situations — — 1 1 1 — Private equity — — 9 9 3 2 Total $ 59 $ 377 $ 23 $ 459 100 % 100 % Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Net Asset Value as a Practical Expedient Total Target Allocation Actual Allocation At December 31, 2020: (Level 1) (Level 2) (NAV) (in millions) Georgia Power Assets: Equity: 60 % 64 % Domestic equity $ 58 $ 10 $ — $ 68 International equity 21 50 — 71 Fixed income: 33 30 U.S. Treasury, government, and agency bonds — 8 — 8 Corporate bonds — 13 — 13 Pooled funds — 46 — 46 Cash equivalents and other 5 — — 5 Trust-owned life insurance — 188 — 188 Real estate investments 5 — 13 18 4 4 Special situations — — 1 1 1 — Private equity — — 9 9 2 2 Total $ 89 $ 315 $ 23 $ 427 100 % 100 % Mississippi Power Assets: Equity: 43 % 46 % Domestic equity $ 4 $ 2 $ — $ 6 International equity 4 2 — 6 Fixed income: 37 36 U.S. Treasury, government, and agency bonds — 5 — 5 Corporate bonds — 2 — 2 Pooled funds — 1 — 1 Cash equivalents and other 1 — — 1 Real estate investments 1 — 2 3 11 11 Special situations — — — — 2 1 Private equity — — 2 2 7 6 Total $ 10 $ 12 $ 4 $ 26 100 % 100 % Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Net Asset Value as a Practical Expedient Total Target Allocation Actual Allocation At December 31, 2020: (Level 1) (Level 2) (NAV) (in millions) Southern Company Gas Assets: Equity: 72 % 76 % Domestic equity $ 2 $ 66 $ — $ 68 International equity 2 25 — 27 Fixed income: 26 22 U.S. Treasury, government, and agency bonds — 1 — 1 Corporate bonds — 1 — 1 Pooled funds — 25 — 25 Cash equivalents and other 1 — — 1 Real estate investments — — 1 1 1 1 Private equity — — 1 1 1 1 Total $ 5 $ 118 $ 2 $ 125 100 % 100 % Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Net Asset Value as a Practical Expedient Target Allocation Actual Allocation At December 31, 2019: (Level 1) (Level 2) (NAV) Total (in millions) Southern Company Assets: Equity: 63 % 64 % Domestic equity $ 95 $ 81 $ — $ 176 International equity 69 80 — 149 Fixed income: 28 30 U.S. Treasury, government, and agency bonds — 31 — 31 Corporate bonds — 35 — 35 Pooled funds — 82 — 82 Cash equivalents and other 42 — — 42 Trust-owned life insurance — 463 — 463 Real estate investments 15 — 38 53 5 4 Special situations — — 4 4 1 — Private equity — — 25 25 3 2 Total $ 221 $ 772 $ 67 $ 1,060 100 % 100 % Alabama Power Assets: Equity: 68 % 67 % Domestic equity $ 26 $ 8 $ — $ 34 International equity 21 11 — 32 Fixed income: 24 27 U.S. Treasury, government, and agency bonds — 10 — 10 Corporate bonds — 11 — 11 Pooled funds — 6 — 6 Cash equivalents and other 12 — — 12 Trust-owned life insurance — 281 — 281 Real estate investments 5 — 12 17 4 4 Special situations — — 1 1 1 — Private equity — — 8 8 3 2 Total $ 64 $ 327 $ 21 $ 412 100 % 100 % Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Net Asset Value as a Practical Expedient Target Allocation Actual Allocation At December 31, 2019: (Level 1) (Level 2) (NAV) Total (in millions) Georgia Power Assets: Equity: 60 % 61 % Domestic equity $ 48 $ 7 $ — $ 55 International equity 25 36 — 61 Fixed income: 33 34 U.S. Treasury, government, and agency bonds — 7 — 7 Corporate bonds — 11 — 11 Pooled funds — 45 — 45 Cash equivalents and other 16 — — 16 Trust-owned life insurance — 182 — 182 Real estate investments 5 — 11 16 4 3 Special situations — — 1 1 1 — Private equity — — 8 8 2 2 Total $ 94 $ 288 $ 20 $ 402 100 % 100 % Mississippi Power Assets: Equity: 43 % 41 % Domestic equity $ 3 $ 1 $ — $ 4 International equity 4 2 — 6 Fixed income: 37 42 U.S. Treasury, government, and agency bonds — 6 — 6 Corporate bonds — 2 — 2 Pooled funds — 1 — 1 Cash equivalents and other 2 — — 2 Real estate investments 1 — 2 3 11 10 Special situations — — — — 2 1 Private equity — — 1 1 7 6 Total $ 10 $ 12 $ 3 $ 25 100 % 100 % Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Net Asset Value as a Practical Expedient Target Allocation Actual Allocation At December 31, 2019: (Level 1) (Level 2) (NAV) Total (in millions) Southern Company Gas Assets: Equity: 72 % 73 % Domestic equity $ 2 $ 58 $ — $ 60 International equity 2 21 — 23 Fixed income: 26 25 U.S. Treasury, government, and agency bonds — 1 — 1 Corporate bonds — 1 — 1 Pooled funds — 25 — 25 Cash equivalents and other 2 — — 2 Real estate investments — — 1 1 1 1 Private equity — — 1 1 1 1 Total $ 6 $ 106 $ 2 $ 114 100 % 100 % |
Total matching contributions | Total matching contributions made to the plans for 2020, 2019, and 2018 were as follows: Southern Company Alabama Georgia Mississippi Southern Southern Company Gas (in millions) 2020 $ 120 $ 26 $ 29 $ 5 $ 2 $ 16 2019 113 25 27 4 2 15 2018 119 24 26 5 3 18 |
STOCK COMPENSATION (Tables)
STOCK COMPENSATION (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Share-based Payment Arrangement [Abstract] | |
Schedule of employees participating in stock-based compensation programs | At December 31, 2020, the number of current and former employees participating in stock-based compensation programs for the Registrants was as follows: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas Number of employees 1,958 263 295 86 46 204 |
Assumptions used in the pricing model and the weighted average grant-date fair value of performance share award units granted | The following table shows the assumptions used in the pricing model and the weighted average grant-date fair value of TSR awards granted: Year Ended December 31 2020 2019 2018 Expected volatility 15.4% 15.6% 14.9% Expected term (in years) 3 3 3 Interest rate 1.4% 2.4% 2.4% Weighted average grant-date fair value $77.65 $62.71 $43.75 |
Schedule of compensation costs and related tax benefits | Total PSU compensation cost, and the related tax benefit recognized in income, for the years ended December 31, 2020, 2019, and 2018 are as follows: 2020 2019 2018 (in millions) Southern Company Compensation cost recognized in income $ 84 $ 77 $ 91 Tax benefit of compensation cost recognized in income 22 20 24 Southern Company Gas Compensation cost recognized in income $ 13 $ 14 $ 11 Tax benefit of compensation cost recognized in income 4 4 3 Total intrinsic value of options exercised, and the related tax benefit, for the years ended December 31, 2020, 2019, and 2018 are presented below: Year Ended December 31 2020 2019 2018 (in millions) Southern Company Intrinsic value of options exercised $ 38 $ 167 $ 9 Tax benefit of options exercised 9 35 2 Alabama Power Intrinsic value of options exercised $ 5 $ 21 $ 2 Tax benefit of options exercised 1 4 — Georgia Power Intrinsic value of options exercised $ 9 $ 30 $ 2 Tax benefit of options exercised 2 6 — |
Share-based compensation, stock options, activity | Southern Company's activity in the stock option program for 2020 is summarized below: Shares Subject to Option Weighted Average Exercise Price (in millions) Outstanding at December 31, 2019 5.9 $ 42.52 Exercised 1.6 41.13 Outstanding and Exercisable at December 31, 2020 4.3 $ 43.04 |
Schedule of aggregate and total intrinsic value of options exercised | At December 31, 2020, the aggregate intrinsic value for the options outstanding and exercisable was as follows: Southern Company Alabama Power Georgia Power Southern Company Gas (in millions) Total intrinsic value for outstanding and exercisable options $ 78 $ 8 $ 25 $ 6 |
FAIR VALUE MEASUREMENTS (Tables
FAIR VALUE MEASUREMENTS (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Fair Value Disclosures [Abstract] | |
Assets and liabilities measured at fair value on a recurring basis | The fair value increases (decreases) of the Funds, including unrealized gains (losses) and reinvested interest and dividends and excluding the Funds' expenses, for 2020, 2019, and 2018 are shown in the table below. Southern Company Alabama Georgia (in millions) Fair value increases (decreases) 2020 $ 280 $ 142 $ 138 2019 344 194 150 2018 (67) (38) (29) Unrealized gains (losses) At December 31, 2020 $ 220 $ 121 $ 99 At December 31, 2019 259 149 110 At December 31, 2018 (183) (96) (87) At December 31, 2020, assets and liabilities measured at fair value on a recurring basis during the period, together with their associated level of the fair value hierarchy, were as follows: Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2020: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Southern Company Assets: Energy-related derivatives (a) $ 401 $ 271 $ 32 $ — $ 704 Interest rate derivatives — 20 — — 20 Foreign currency derivatives — 87 — — 87 Investments in trusts: (b)(c) Domestic equity 862 151 — — 1,013 Foreign equity 85 253 — — 338 U.S. Treasury and government agency securities — 284 — — 284 Municipal bonds — 85 — — 85 Pooled funds – fixed income — 17 — — 17 Corporate bonds 13 386 — — 399 Mortgage and asset backed securities — 83 — — 83 Private equity — — — 76 76 Cash and cash equivalents 1 — — — 1 Other 28 7 — — 35 Cash equivalents 575 9 — — 584 Other investments 9 24 — — 33 Total $ 1,974 $ 1,677 $ 32 $ 76 $ 3,759 Liabilities: Energy-related derivatives (a) $ 389 $ 204 $ 4 $ — $ 597 Foreign currency derivatives — 23 — — 23 Contingent consideration — — 17 — 17 Total $ 389 $ 227 $ 21 $ — $ 637 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2020: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Alabama Power Assets: Energy-related derivatives $ — $ 12 $ — $ — $ 12 Nuclear decommissioning trusts: (b) Domestic equity 543 141 — — 684 Foreign equity 85 73 — — 158 U.S. Treasury and government agency securities — 21 — — 21 Municipal bonds — 1 — — 1 Corporate bonds 13 167 — — 180 Mortgage and asset backed securities — 29 — — 29 Private equity — — — 76 76 Other 7 — — — 7 Cash equivalents 311 9 — — 320 Other investments — 24 — — 24 Total $ 959 $ 477 $ — $ 76 $ 1,512 Liabilities: Energy-related derivatives $ — $ 7 $ — $ — $ 7 Georgia Power Assets: Energy-related derivatives $ — $ 15 $ — $ — $ 15 Nuclear decommissioning trusts: (b)(c) Domestic equity 319 1 — — 320 Foreign equity — 177 — — 177 U.S. Treasury and government agency securities — 263 — — 263 Municipal bonds — 84 — — 84 Corporate bonds — 219 — — 219 Mortgage and asset backed securities — 54 — — 54 Other 21 7 — — 28 Total $ 340 $ 820 $ — $ — $ 1,160 Liabilities: Energy-related derivatives $ — $ 13 $ — $ — $ 13 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2020: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Mississippi Power Assets: Energy-related derivatives $ — $ 9 $ — $ — $ 9 Cash equivalents 21 — — — 21 Total $ 21 $ 9 $ — $ — $ 30 Liabilities: Energy-related derivatives $ — $ 9 $ — $ — $ 9 Southern Power Assets: Energy-related derivatives $ — $ 2 $ — $ — $ 2 Foreign currency derivatives — 87 — — 87 Total $ — $ 89 $ — $ — $ 89 Liabilities: Energy-related derivatives $ — $ 3 $ — $ — $ 3 Foreign currency derivatives — 23 — — 23 Contingent consideration — — 17 — 17 Total $ — $ 26 $ 17 $ — $ 43 Southern Company Gas Assets: Energy-related derivatives (a) $ 401 $ 233 $ 32 $ — $ 666 Non-qualified deferred compensation trusts: Domestic equity — 9 — — 9 Foreign equity — 3 — — 3 Pooled funds - fixed income — 17 — — 17 Cash equivalents 1 — — — 1 Total $ 402 $ 262 $ 32 $ — $ 696 Liabilities: Energy-related derivatives (a)(b) $ 389 $ 172 $ 4 $ — $ 565 (a) Excludes $6 million associated with premiums and certain weather derivatives accounted for based on intrinsic value rather than fair value and cash collateral of $28 million. (b) Excludes receivables related to investment income, pending investment sales, payables related to pending investment purchases, and currencies. See Note 6 under "Nuclear Decommissioning" for additional information. (c) Includes investment securities pledged to creditors and collateral received and excludes payables related to the securities lending program. See Note 6 under "Nuclear Decommissioning" for additional information. At December 31, 2019, assets and liabilities measured at fair value on a recurring basis during the period, together with their associated level of the fair value hierarchy, were as follows: Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2019: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Southern Company Assets: Energy-related derivatives (a) $ 388 $ 267 $ 22 $ — $ 677 Interest rate derivatives — 2 — — 2 Foreign currency derivatives — 16 — — 16 Investments in trusts: (b)(c) Domestic equity 751 135 — — 886 Foreign equity 68 220 — — 288 U.S. Treasury and government agency securities — 307 — — 307 Municipal bonds — 85 — — 85 Pooled funds – fixed income — 17 — — 17 Corporate bonds 23 297 — — 320 Mortgage and asset backed securities — 87 — — 87 Private equity — — — 56 56 Cash and cash equivalents 1 — — — 1 Other 17 5 — — 22 Cash equivalents 1,393 2 — — 1,395 Other investments 9 21 — — 30 Total $ 2,650 $ 1,461 $ 22 $ 56 $ 4,189 Liabilities: Energy-related derivatives (a) $ 442 $ 254 $ 7 $ — $ 703 Interest rate derivatives — 24 — — 24 Foreign currency derivatives — 24 — — 24 Contingent consideration — — 19 — 19 Total $ 442 $ 302 $ 26 $ — $ 770 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2019: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Alabama Power Assets: Energy-related derivatives $ — $ 4 $ — $ — $ 4 Nuclear decommissioning trusts: (b) Domestic equity 488 123 — — 611 Foreign equity 68 64 — — 132 U.S. Treasury and government agency securities — 21 — — 21 Municipal bonds — 1 — — 1 Corporate bonds 23 144 — — 167 Mortgage and asset backed securities — 29 — — 29 Private equity — — — 56 56 Other 3 1 — — 4 Cash equivalents 691 2 — — 693 Other investments — 21 — — 21 Total $ 1,273 $ 410 $ — $ 56 $ 1,739 Liabilities: Energy-related derivatives $ — $ 24 $ — $ — $ 24 Georgia Power Assets: Energy-related derivatives $ — $ 4 $ — $ — $ 4 Nuclear decommissioning trusts: (b)(c) Domestic equity 263 1 — — 264 Foreign equity — 152 — — 152 U.S. Treasury and government agency securities — 286 — — 286 Municipal bonds — 84 — — 84 Corporate bonds — 153 — — 153 Mortgage and asset backed securities — 57 — — 57 Other 13 4 — — 17 Total $ 276 $ 741 $ — $ — $ 1,017 Liabilities: Energy-related derivatives $ — $ 53 $ — $ — $ 53 Interest rate derivatives — 17 — — 17 Total $ — $ 70 $ — $ — $ 70 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Net Asset Value as a Practical Expedient At December 31, 2019: (Level 1) (Level 2) (Level 3) (NAV) Total (in millions) Mississippi Power Assets: Energy-related derivatives $ — $ 1 $ — $ — $ 1 Cash equivalents 281 — — — 281 Total $ 281 $ 1 $ — $ — $ 282 Liabilities: Energy-related derivatives $ — $ 27 $ — $ — $ 27 Southern Power Assets: Energy-related derivatives $ — $ 3 $ — $ — $ 3 Foreign currency derivatives — 16 — — 16 Cash equivalents 113 — — — 113 Total $ 113 $ 19 $ — $ — $ 132 Liabilities: Energy-related derivatives $ — $ 3 $ — $ — $ 3 Foreign currency derivatives — 24 — — 24 Contingent consideration — — 19 — 19 Total $ — $ 27 $ 19 $ — $ 46 Southern Company Gas Assets: Energy-related derivatives (a) $ 388 $ 255 $ 22 $ — $ 665 Interest rate derivatives — 2 — — 2 Non-qualified deferred compensation trusts: Domestic equity — 11 — — 11 Foreign equity — 4 — — 4 Pooled funds - fixed income — 17 — — 17 Cash equivalents 1 — — — 1 Cash equivalents 8 — — — 8 Total $ 397 $ 289 $ 22 $ — $ 708 Liabilities: Energy-related derivatives (a)(b) $ 442 $ 147 $ 7 $ — $ 596 (a) Excludes $4 million associated with premiums and certain weather derivatives accounted for based on intrinsic value rather than fair value and cash collateral of $99 million. (c) Excludes receivables related to investment income, pending investment sales, payables related to pending investment purchases, and currencies. See Note 6 under "Nuclear Decommissioning" for additional information. (d) Includes investment securities pledged to creditors and collateral received and excludes payables related to the securities lending program. See Note 6 under "Nuclear Decommissioning" for additional information. |
Financial instruments not having carrying amount equal to fair value | At December 31, 2020 and 2019, other financial instruments for which the carrying amount did not equal fair value were as follows: Southern Company (*) Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (*) (in millions) At December 31, 2020: Long-term debt, including securities due within one year: Carrying amount $ 48,349 $ 8,864 $ 12,825 $ 1,400 $ 3,692 $ 6,626 Fair value 56,264 10,702 15,198 1,590 4,165 7,973 At December 31, 2019: Long-term debt, including securities due within one year: Carrying amount $ 44,561 $ 8,517 $ 11,660 $ 1,589 $ 4,398 $ 5,845 Fair value 48,339 9,525 12,680 1,671 4,708 6,509 (*) The long-term debt of Southern Company Gas is recorded at amortized cost, including the fair value adjustments at the effective date of the 2016 merger with Southern Company. Southern Company Gas amortizes the fair value adjustments over the remaining lives of the respective bonds, the latest being through 2043. |
Schedule of transfers to Level 3 | The following table includes transfers to Level 3, which represent the fair value of Southern Company Gas' commodity derivative contracts that include a significant unobservable component for the first time during the period. 2020 (in millions) Beginning balance $ 14 Transfers to Level 3 70 Transfers from Level 3 (34) Instruments realized or otherwise settled during period (16) Changes in fair value (6) Ending balance $ 28 |
DERIVATIVES (Tables)
DERIVATIVES (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Derivative Instruments and Hedging Activities Disclosure [Abstract] | |
Schedule of energy-related derivatives | At December 31, 2020, the net volume of energy-related derivative contracts for natural gas positions, together with the longest hedge date over which the respective entity is hedging its exposure to the variability in future cash flows for forecasted transactions and the longest non-hedge date for derivatives not designated as hedges, were as follows: Net Longest Longest (in millions) Southern Company (*) 835 2024 2031 Alabama Power 78 2024 — Georgia Power 135 2023 — Mississippi Power 89 2024 — Southern Power 10 2022 2021 Southern Company Gas (*) 523 2022 2031 (*) Southern Company Gas' derivative instruments include both long and short natural gas positions. A long position is a contract to purchase natural gas and a short position is a contract to sell natural gas. Southern Company Gas' volume represents the net of long natural gas positions of 4,421 million mmBtu and short natural gas positions of 3,898 million mmBtu at December 31, 2020, which is also included in Southern Company's total volume. |
Notional amount of interest rate derivatives | At December 31, 2020, the following interest rate derivatives were outstanding: Notional Interest Weighted Average Interest Hedge Fair Value (in millions) (in millions) Cash Flow Hedges of Existing Debt Mississippi Power $ 60 1-month LIBOR 0.58% December 2021 $ — Fair Value Hedges of Existing Debt Southern Company parent 1,500 2.35% 1-month LIBOR + 0.87% July 2021 20 Southern Company $ 1,560 $ 20 |
Schedule of foreign exchange contracts | At December 31, 2020, the following foreign currency derivatives were outstanding: Pay Notional Pay Rate Receive Notional Receive Rate Hedge Fair Value (in millions) (in millions) (in millions) Cash Flow Hedges of Existing Debt Southern Power $ 677 2.95% € 600 1.00% June 2022 $ 40 Southern Power 564 3.78% 500 1.85% June 2026 25 Total $ 1,241 € 1,100 $ 65 |
Fair value of energy-related derivatives and interest rate derivatives | At December 31, 2020 and 2019, the fair value of energy-related derivatives, interest rate derivatives, and foreign currency derivatives was reflected in the balance sheets as follows: 2020 2019 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) Southern Company Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Assets from risk management activities/Other current liabilities $ 24 $ 11 $ 3 $ 70 Other deferred charges and assets/Other deferred credits and liabilities 18 19 6 44 Total derivatives designated as hedging instruments for regulatory purposes $ 42 $ 30 $ 9 $ 114 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Assets from risk management activities/Other current liabilities $ 3 $ 5 $ 1 $ 6 Interest rate derivatives: Assets from risk management activities/Other current liabilities 20 — 2 23 Other deferred charges and assets/Other deferred credits and liabilities — — — 1 Foreign currency derivatives: Assets from risk management activities/Other current liabilities — 23 — 24 Other deferred charges and assets/Other deferred credits and liabilities 87 — 16 — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 110 $ 28 $ 19 $ 54 Derivatives not designated as hedging instruments Energy-related derivatives: Assets from risk management activities/Other current liabilities $ 388 $ 331 $ 461 $ 358 Other deferred charges and assets/Other deferred credits and liabilities 270 232 207 225 Total derivatives not designated as hedging instruments $ 658 $ 563 $ 668 $ 583 Gross amounts recognized $ 810 $ 621 $ 696 $ 751 Gross amounts offset (a) $ (529) $ (557) $ (463) $ (562) Net amounts recognized in the Balance Sheets (b) $ 281 $ 64 $ 233 $ 189 2020 2019 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) Alabama Power Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets/Other current liabilities $ 7 $ 2 $ 2 $ 14 Other deferred charges and assets/Other deferred credits and liabilities 5 5 2 10 Total derivatives designated as hedging instruments for regulatory purposes $ 12 $ 7 $ 4 $ 24 Gross amounts recognized $ 12 $ 7 $ 4 $ 24 Gross amounts offset $ (7) $ (7) $ (2) $ (2) Net amounts recognized in the Balance Sheets $ 5 $ — $ 2 $ 22 Georgia Power Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets/Other current liabilities $ 7 $ 5 $ 1 $ 32 Other deferred charges and assets/Other deferred credits and liabilities 8 8 3 21 Total derivatives designated as hedging instruments for regulatory purposes $ 15 $ 13 $ 4 $ 53 Derivatives designated as hedging instruments in cash flow and fair value hedges Interest rate derivatives: Other current assets/Other current liabilities $ — $ — $ — $ 17 Gross amounts recognized $ 15 $ 13 $ 4 $ 70 Gross amounts offset $ (12) $ (12) $ (3) $ (3) Net amounts recognized in the Balance Sheets $ 3 $ 1 $ 1 $ 67 2020 2019 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) Mississippi Power Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets/Other current liabilities $ 4 $ 3 $ — $ 15 Other deferred charges and assets/Other deferred credits and liabilities 5 6 1 12 Total derivatives designated as hedging instruments for regulatory purposes $ 9 $ 9 $ 1 $ 27 Gross amounts recognized $ 9 $ 9 $ 1 $ 27 Gross amounts offset $ (7) $ (7) $ (1) $ (1) Net amounts recognized in the Balance Sheets $ 2 $ 2 $ — $ 26 Southern Power Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets/Other current liabilities $ 2 $ 2 $ 1 $ 2 Foreign currency derivatives: Other current assets/Other current liabilities — 23 — 24 Other deferred charges and assets/Other deferred credits and liabilities 87 — 16 — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 89 $ 25 $ 17 $ 26 Derivatives not designated as hedging instruments Energy-related derivatives: Other current assets/Other current liabilities $ — $ 1 $ 2 $ 1 Net amounts recognized in the Balance Sheets $ 89 $ 26 $ 19 $ 27 2020 2019 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) Southern Company Gas Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Assets from risk management activities/Other current liabilities $ 6 $ 1 $ — $ 9 Other deferred charges and assets/Other deferred credits and liabilities — — — 1 Total derivatives designated as hedging instruments for regulatory purposes $ 6 $ 1 $ — $ 10 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Assets from risk management activities/Other current liabilities $ 1 $ 3 $ — $ 4 Interest rate derivatives: Assets from risk management activities/Other current liabilities — — 2 — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 1 $ 3 $ 2 $ 4 Derivatives not designated as hedging instruments Energy-related derivatives: Assets from risk management activities/Other current liabilities $ 388 $ 330 $ 459 $ 357 Other deferred charges and assets/Other deferred credits and liabilities 270 232 207 225 Total derivatives not designated as hedging instruments $ 658 $ 562 $ 666 $ 582 Gross amounts recognized $ 665 $ 566 $ 668 $ 596 Gross amounts offset (a) $ (503) $ (531) $ (456) $ (555) Net amounts recognized in the Balance Sheets (b) $ 162 $ 35 $ 212 $ 41 (a) Gross amounts offset include cash collateral held on deposit in broker margin accounts of $28 million and $99 million at December 31, 2020 and 2019, respectively. (b) Net amounts of derivative instruments outstanding exclude immaterial premium and intrinsic value associated with weather derivatives for all periods presented. |
Pre-tax effects on the balance sheets | At December 31, 2020 and 2019, the pre-tax effects of unrealized derivative gains (losses) arising from energy-related derivative instruments designated as regulatory hedging instruments and deferred were as follows: Regulatory Hedge Unrealized Gain (Loss) Recognized in the Balance Sheet at December 31, 2020 Derivative Category and Balance Sheet Southern Alabama Georgia Mississippi Southern Company Gas (in millions) Energy-related derivatives: Other regulatory assets, deferred $ (2) $ — $ (1) $ (1) $ — Other regulatory liabilities, current 12 5 2 1 4 Other regulatory liabilities, deferred 2 1 1 — — Total energy-related derivative gains (losses) $ 12 $ 6 $ 2 $ — $ 4 Regulatory Hedge Unrealized Gain (Loss) Recognized in the Balance Sheet at December 31, 2019 Derivative Category and Balance Sheet Southern Alabama Georgia Mississippi Southern Company Gas (in millions) Energy-related derivatives: Other regulatory assets, current $ (63) $ (14) $ (31) $ (15) $ (3) Other regulatory assets, deferred (37) (8) (18) (11) — Other regulatory liabilities, current 6 2 — — 4 Total energy-related derivative gains (losses) $ (94) $ (20) $ (49) $ (26) $ 1 |
Pre-tax effects of interest rate derivatives, designated as cash flow hedging instruments | For the years ended December 31, 2020, 2019, and 2018, the pre-tax effects of cash flow hedge accounting on AOCI for the applicable Registrants were as follows: Gain (Loss) Recognized in OCI on Derivative 2020 2019 2018 (in millions) Southern Company Energy-related derivatives $ (8) $ (13) $ 17 Interest rate derivatives (26) (57) (1) Foreign currency derivatives 48 (84) (78) Total $ 14 $ (154) $ (62) Georgia Power Interest rate derivatives $ (3) $ (59) $ — Southern Power Energy-related derivatives $ (2) $ (4) $ 10 Foreign currency derivatives 48 (84) (78) Total $ 46 $ (88) $ (68) Southern Company Gas Energy-related derivatives $ (6) $ (9) $ 7 Interest rate derivatives (23) 2 — Total $ (29) $ (7) $ 7 |
Pre-tax effect of interest rate and energy related derivatives | The pre-tax effects of cash flow and fair value hedge accounting on income for the years ended December 31, 2020, 2019, and 2018 were as follows: Location and Amount of Gain (Loss) Recognized in Income on Cash Flow and Fair Value Hedging Relationships 2020 2019 2018 (in millions) Southern Company Total cost of natural gas $ 972 $ 1,319 $ 1,539 Gain (loss) on energy-related cash flow hedges (a) (8) (2) 2 Total depreciation and amortization 3,518 3,038 3,131 Gain (loss) on energy-related cash flow hedges (a) (3) (6) 7 Total interest expense, net of amounts capitalized (1,821) (1,736) (1,842) Gain (loss) on interest rate cash flow hedges (a) (26) (20) (21) Gain (loss) on foreign currency cash flow hedges (a) (23) (24) (24) Gain (loss) on interest rate fair value hedges (b) 27 42 (12) Total other income (expense), net 336 252 114 Gain (loss) on foreign currency cash flow hedges (a)(c) 114 (24) (60) Southern Power Total depreciation and amortization $ 494 $ 479 $ 493 Gain (loss) on energy-related cash flow hedges (a) (3) (6) 7 Total interest expense, net of amounts capitalized (151) (169) (183) Gain (loss) on foreign currency cash flow hedges (a) (23) (24) (24) Total other income (expense), net 19 47 23 Gain (loss) on foreign currency cash flow hedges (a)(c) 114 (24) (60) (a) Reclassified from AOCI into earnings. (b) For fair value hedges, changes in the fair value of the derivative contracts are generally equal to changes in the fair value of the underlying debt and have no material impact on income. (c) The reclassification from AOCI into other income (expense), net completely offsets currency gains and losses arising from changes in the U.S. currency exchange rates used to record the euro-denominated notes. |
Schedule of fair value hedging instruments, statements of financial performance and financial position, location | At December 31, 2020 and 2019, the following amounts were recorded on the balance sheets related to cumulative basis adjustments for fair value hedges: Carrying Amount of the Hedged Item Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item Balance Sheet Location of Hedged Items At December 31, 2020 At December 31, 2019 At December 31, 2020 At December 31, 2019 (in millions) (in millions) Southern Company Securities due within one year $ (1,509) $ (599) $ (10) $ — Long-term debt — (1,494) — 3 |
Pre-tax effect of interest rate and energy related derivatives | The pre-tax effects of energy-related derivatives not designated as hedging instruments on the statements of income of Southern Company and Southern Company Gas for the years ended December 31, 2020, 2019, and 2018 were as follows: Gain (Loss) Derivatives in Non-Designated Hedging Relationships Statements of Income Location 2020 2019 2018 (in millions) Energy-related derivatives Natural gas revenues (*) $ 134 $ 223 $ (122) Cost of natural gas 15 10 (6) Total derivatives in non-designated hedging relationships $ 149 $ 233 $ (128) (*) Excludes the impact of weather derivatives recorded in natural gas revenues of $9 million, $3 million, and $5 million for the years ended December 31, 2020, 2019, and 2018, respectively, as they are accounted for based on intrinsic value rather than fair value. |
ACQUISITIONS AND DISPOSITIONS (
ACQUISITIONS AND DISPOSITIONS (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Business Combinations [Abstract] | |
Schedule of business acquisitions, by acquisition | Project Resource Seller Approximate Nameplate Capacity ( MW ) Location Southern COD PPA Contract Period Asset Acquisitions During 2020 Beech Ridge II Wind Invenergy Renewables LLC 56 Greenbrier County, WV 100% of Class A (a) May 12 years Asset Acquisitions During 2019 DSGP (b) Fuel Cell Bloom Energy 28 Delaware 100% of Class B N/A (c) 15 years (d) Asset Acquisitions During 2018 Gaskell West 1 Solar Recurrent Energy Development Holdings, LLC 20 Kern County, CA 100% of Class B (e) March 2018 20 years (a) In May 2020, Southern Power purchased a controlling interest and now consolidates the project's operating results in its financial statements. The Class B member owns the noncontrolling interest. (b) During 2019, Southern Power purchased a controlling interest and now consolidates the project's operating results in its financial statements. The Class A and Class C members each own a noncontrolling interest. Southern Power records net income attributable to noncontrolling interests for approximately 10 MWs of the facility. (c) Southern Power's 18-MW share of the facility was repowered between June and August 2019. In December 2019, a Class C member joined the existing partnership between the Class A member and Southern Power and made an investment to repower the remaining 10 MWs. (d) Remaining PPA contract period at the time of acquisition. (e) Southern Power owns a controlling interest under a tax equity partnership. |
Schedule of construction projects | During 2020, Southern Power completed construction of and placed in service the Reading and Skookumchuck wind facilities, commenced construction of the Garland and Tranquillity battery energy storage facilities, and acquired and commenced construction of the Glass Sands wind facility. Total aggregate construction costs, excluding acquisition costs, are expected to be between $392 million and $460 million for the facilities under construction. At December 31, 2020, the total costs of construction incurred and included in CWIP for these projects were $34 million. The ultimate outcome of these matters cannot be determined at this time. Project Resource Approximate Nameplate Capacity ( MW ) Location Actual/Expected PPA Contract Period Projects Under Construction at December 31, 2020 Garland Solar Storage (a) Battery energy storage system 88 Kern County, CA Third quarter 2021 20 years Tranquillity Solar Storage (a) Battery energy storage system 72 Fresno County, CA Fourth quarter 2021 20 years Glass Sands (b) Wind 118 Murray County, OK Fourth quarter 2021 12 years Projects Completed During 2020 Skookumchuck (c) Wind 136 Lewis and Thurston Counties, WA November 2020 20 years Reading (d) Wind 200 Osage and Lyon Counties, KS May 2020 12 years Projects Completed During 2019 (e) Wildhorse Mountain (f) Wind 100 Pushmataha County, OK December 2019 20 years (a) In December 2020, Southern Power restructured its ownership of the project by contributing the Class A membership interests to an existing partnership and selling 100% of the Class B membership interests while retaining the controlling interest. Prior to commercial operation, Southern Power may restructure the project ownership again and enter into additional partnerships, but expects to retain the controlling interest. The ultimate outcome of this matter cannot be determined at this time. (b) In December 2020, Southern Power purchased 100% of the membership interests of the Glass Sands facility. (c) In October 2019, Southern Power purchased 100% of the membership interests of the Skookumchuck facility pursuant to a joint development arrangement. In November 2020, Southern Power completed a tax equity transaction whereby it received $121 million, resulting in 100% ownership of the Class B membership interests. Southern Power subsequently sold a noncontrolling interest in the Class B membership interests and now retains the controlling ownership interest in the facility. (d) In 2018, Southern Power purchased 100% of the membership interests of the Reading facility pursuant to a joint development arrangement. In June 2020, Southern Power completed a tax equity transaction whereby it received $156 million and owns 100% of the Class B membership interests. (e) During 2019, Southern Power also completed the expansion of Plant Mankato, which was sold to a subsidiary of Xcel on January 17, 2020. See "Sales of Natural Gas and Biomass Plants" below for additional information. (f) In 2018, Southern Power purchased 100% of the membership interests of the Wildhorse Mountain facility. In December 2019, Southern Power entered into a tax equity partnership and owns 100% of the Class B membership interests. |
Disposal groups, including discontinued operations | The following table provides the major classes of assets and liabilities classified as held for sale for Southern Company, Southern Power, and Southern Company Gas at December 31, 2020 and/or 2019: Southern Southern Southern Company Gas At December 31, At December 31, At December 31, 2020 2019 2019 2019 (in millions) Assets Held for Sale: Current assets $ — $ 19 $ 17 $ 2 Total property, plant, and equipment 8 565 547 18 Goodwill and other intangible assets — 40 40 — Equity investments in unconsolidated subsidiaries — 151 — 151 Leveraged leases 52 — — — Other non-current assets — 14 14 — Total Assets Held for Sale $ 60 $ 789 $ 618 $ 171 Liabilities Held for Sale (all current): $ — $ 5 $ 3 $ 2 2020 2019 2018 (in millions) Earnings before income taxes: Gulf Power N/A N/A $ 140 Southern Power's Florida Plants (a)(b) N/A N/A $ 49 Southern Power's Plant Nacogdoches (a)(c) N/A $ 13 $ 27 Southern Power's Plant Mankato (a)(d) $ 2 $ 29 N/M N/M - Not material (a) Earnings before income taxes reflect the cessation of depreciation and amortization on the long-lived assets being sold upon classification as held for sale. (b) 2018 amount represents the period from January 1, 2018 to December 4, 2018 (the divestiture date). (c) 2019 amount represents the period from January 1, 2019 to June 13, 2019 (the divestiture date). (d) 2020 amount represents the period from January 1, 2020 to January 17, 2020 (the divestiture date). |
SEGMENT AND RELATED INFORMATI_2
SEGMENT AND RELATED INFORMATION (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Segment Reporting [Abstract] | |
Financial data for business segments | Financial data for business segments and products and services for the years ended December 31, 2020, 2019, and 2018 was as follows: Electric Utilities Traditional Southern Eliminations Total Southern Company Gas All Eliminations Consolidated (in millions) 2020 Operating revenues $ 15,135 $ 1,733 $ (371) $ 16,497 $ 3,434 $ 596 $ (152) $ 20,375 Depreciation and amortization 2,447 494 — 2,941 500 77 — 3,518 Interest income 26 4 — 30 5 6 (4) 37 Earnings from equity method investments — — — — 141 12 — 153 Interest expense 825 151 — 976 231 614 — 1,821 Income taxes (benefit) 514 3 — 517 173 (297) — 393 Segment net income (loss) (a)(b)(c)(d)(e) 2,877 238 — 3,115 590 (592) 6 3,119 Goodwill — 2 — 2 5,015 263 — 5,280 Total assets 85,486 13,235 (680) 98,041 22,630 3,168 (904) 122,935 2019 Operating revenues $ 15,569 $ 1,938 $ (412) $ 17,095 $ 3,792 $ 690 $ (158) $ 21,419 Depreciation and amortization 1,993 479 — 2,472 487 79 — 3,038 Interest income 38 9 — 47 3 16 (6) 60 Earnings from equity method investments 2 3 — 5 157 — — 162 Interest expense 818 169 — 987 232 517 — 1,736 Income taxes (benefit) 764 (56) — 708 130 960 — 1,798 Segment net income (loss) (a)(f)(g)(h) 2,929 339 — 3,268 585 908 (22) 4,739 Goodwill — 2 — 2 5,015 263 — 5,280 Total assets 81,063 14,300 (713) 94,650 21,687 3,511 (1,148) 118,700 2018 Operating revenues $ 16,843 $ 2,205 $ (477) $ 18,571 $ 3,909 $ 1,213 $ (198) $ 23,495 Depreciation and amortization 2,072 493 — 2,565 500 66 — 3,131 Interest income 23 8 — 31 4 8 (5) 38 Earnings from equity method investments (1) — — (1) 148 2 (1) 148 Interest expense 852 183 — 1,035 228 580 (1) 1,842 Income taxes (benefit) 371 (164) — 207 464 (222) — 449 Segment net income (loss) (a)(b)(i)(j) 2,117 187 — 2,304 372 (453) 3 2,226 Goodwill — 2 — 2 5,015 298 — 5,315 Total assets 79,382 14,883 (306) 93,959 21,448 3,285 (1,778) 116,914 (a) Attributable to Southern Company. (b) For the traditional electric operating companies, includes pre-tax charges at Georgia Power for estimated loss on Plant Vogtle Units 3 and 4 of $325 million ($242 million after tax) in 2020 and $1.1 billion ($0.8 billion after tax) in 2018. See Note 2 under "Georgia Power – Nuclear Construction" for additional information. (c) For Southern Power, includes a $39 million pre-tax gain ($23 million gain after tax) on the sale of Plant Mankato. See Note 15 under "Southern Power" for additional information. (d) For Southern Company Gas, includes a $22 million pre-tax gain ($16 million gain after tax) on the sale of Jefferson Island. See Note 15 under "Southern Company Gas" for additional information. (e) For the "All Other" column, includes pre-tax impairment charges totaling $206 million ($105 million after tax) related to leveraged lease investments. See Note 3 under "Other Matters – Southern Company" for additional information. (f) For Southern Power, includes a $23 million pre-tax gain ($88 million gain after tax) on the sale of Plant Nacogdoches. See Note 15 under "Southern Power" for additional information. (g) For Southern Company Gas, includes pre-tax impairment charges totaling $115 million ($86 million after tax). See Notes 3 and 15 under "Other Matters – Southern Company Gas" and "Southern Company Gas – Sale of Pivotal LNG and Atlantic Coast Pipeline," respectively, for additional information. (h) For the "All Other" column, includes the pre-tax gain associated with the sale of Gulf Power of $2.6 billion ($1.4 billion after tax), the pre-tax loss, including related impairment charges, on the sales of certain PowerSecure business units totaling $58 million ($52 million after tax), and a pre-tax impairment charge of $17 million ($13 million after tax) related to a leveraged lease investment. See Notes 3 and 15 under "Other Matters – Southern Company" and "Southern Company," respectively, for additional information. (i) For Southern Power, includes pre-tax impairment charges of $156 million ($117 million after tax). See Note 15 under "Southern Power" for additional information. (j) For Southern Company Gas, includes a net gain on dispositions of $291 million ($51 million loss after tax), as well as a goodwill impairment charge of $42 million related to the sale of Pivotal Home Solutions. See Note 15 under "Southern Company Gas" for additional information. Financial data for business segments for the years ended December 31, 2020, 2019, and 2018 was as follows: Gas Distribution Operations (a) Gas Pipeline Investments Wholesale Gas Services (b) Gas Marketing Services (c) Total All Other (d) Eliminations Consolidated (in millions) 2020 Operating revenues $ 2,952 $ 32 $ 74 $ 408 $ 3,466 $ 36 $ (68) $ 3,434 Depreciation and amortization 442 5 1 22 470 30 — 500 Operating income (loss) 655 20 20 119 814 (7) 5 812 Earnings from equity method investments — 141 — — 141 — — 141 Interest expense 192 29 4 3 228 3 — 231 Income taxes (benefit) 114 33 3 28 178 (5) — 173 Segment net income (loss) 390 99 14 89 592 (2) — 590 Total assets at December 31, 2020 19,090 1,597 850 1,503 23,040 11,336 (11,746) 22,630 2019 Operating revenues $ 3,028 $ 32 $ 294 $ 456 $ 3,810 $ 44 $ (62) $ 3,792 Depreciation and amortization 422 5 1 26 454 33 — 487 Operating income (loss) 573 20 219 112 924 (154) — 770 Earnings from equity method investments — 162 — — 162 (5) — 157 Interest expense 187 30 5 3 225 7 — 232 Income taxes (benefit) 63 58 52 27 200 (70) — 130 Segment net income (loss) 337 94 163 83 677 (92) — 585 Total assets at December 31, 2019 18,204 1,678 850 1,496 22,228 10,759 (11,300) 21,687 2018 Operating revenues $ 3,186 $ 32 $ 144 $ 568 $ 3,930 $ 55 $ (76) $ 3,909 Depreciation and amortization 409 5 2 37 453 47 — 500 Operating income (loss) 904 20 70 19 1,013 (98) — 915 Earnings from equity method investments — 145 — — 145 3 — 148 Interest expense 178 34 9 6 227 1 — 228 Income taxes (benefit) 409 28 4 54 495 (31) — 464 Segment net income (loss) 334 103 38 (40) 435 (63) — 372 Total assets at December 31, 2018 17,266 1,763 1,302 1,587 21,918 11,112 (11,582) 21,448 (a) Operating revenues for the three gas distribution operations dispositions were $244 million for 2018. Segment net income for gas distribution operations includes a gain on dispositions of $324 million ($16 million after tax) in 2018. (b) The revenues for wholesale gas services are netted with costs associated with its energy and risk management activities. A reconciliation of operating revenues and intercompany revenues is shown in the following table. Third Party Gross Revenues Intercompany Revenues Total Gross Revenues Less Gross Gas Costs Operating Revenues (in millions) 2020 $ 4,544 $ 115 $ 4,659 $ 4,585 $ 74 2019 5,703 275 5,978 5,684 294 2018 6,955 451 7,406 7,262 144 (c) Operating revenues for the gas marketing services disposition were $55 million in 2018. Segment net income for gas marketing services includes a loss on disposition of $33 million ($67 million loss after tax) and a goodwill impairment charge of $42 million in 2018 recorded in contemplation of the sale of Pivotal Home Solutions. (d) Segment net income (loss) for the "All Other" column include s a $22 million pre-tax gain ($16 million g ain after tax) on the sale of Jefferson Island in 2020 and pre-tax impairment charges totaling $115 million ($86 million after tax) in 2019. See Note 3 under "Other Matters – Southern Company Gas" for additional information. |
Financial data for products and services | Products and Services Electric Utilities' Revenues Year Retail Wholesale Other Total (in millions) 2020 $ 13,643 $ 1,945 $ 909 $ 16,497 2019 14,084 2,152 859 17,095 2018 15,222 2,516 833 18,571 Southern Company Gas' Revenues Year Gas Gas All Other Total (in millions) 2020 $ 2,902 $ 408 $ 124 $ 3,434 2019 3,001 456 335 3,792 2018 3,155 568 186 3,909 |
Schedule of reconciliation of operating revenues and intercompany revenues | A reconciliation of operating revenues and intercompany revenues is shown in the following table. Third Party Gross Revenues Intercompany Revenues Total Gross Revenues Less Gross Gas Costs Operating Revenues (in millions) 2020 $ 4,544 $ 115 $ 4,659 $ 4,585 $ 74 2019 5,703 275 5,978 5,684 294 2018 6,955 451 7,406 7,262 144 |
SUMMARY OF SIGNIFICANT ACCOUN_4
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - General (Narrative) (Details) | Dec. 31, 2020electric_companystate |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |
Number of traditional electric operating companies | electric_company | 3 |
Traditional Operating Companies | |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |
Number of states in which entity provides utilities | state | 3 |
SUMMARY OF SIGNIFICANT ACCOUN_5
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Costs for Affiliate Transactions (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Alabama Power | Southern Company Services, Inc. | |||
Related Party Transaction [Line Items] | |||
Costs for services | $ 478 | $ 527 | $ 508 |
Alabama Power | Southern Natural Gas Company, LLC | |||
Related Party Transaction [Line Items] | |||
Costs for services | 15 | 17 | 8 |
Georgia Power | Southern Company Services, Inc. | |||
Related Party Transaction [Line Items] | |||
Costs for services | 639 | 704 | 653 |
Georgia Power | Southern Natural Gas Company, LLC | |||
Related Party Transaction [Line Items] | |||
Costs for services | 108 | 99 | 101 |
Georgia Power | Southern Company Gas | |||
Related Party Transaction [Line Items] | |||
Costs for services | 0 | 4 | 21 |
Mississippi Power | Southern Company Services, Inc. | |||
Related Party Transaction [Line Items] | |||
Costs for services | 149 | 118 | 104 |
Mississippi Power | Alabama Power | Power Pool | |||
Related Party Transaction [Line Items] | |||
Costs for services | 4 | 3 | 15 |
Southern Power | Southern Company Services, Inc. | |||
Related Party Transaction [Line Items] | |||
Costs for services | 87 | 90 | 98 |
Southern Power | Alabama Power | Power Pool | |||
Related Party Transaction [Line Items] | |||
Costs for services | 8 | 14 | 41 |
Southern Power | Southern Natural Gas Company, LLC | |||
Related Party Transaction [Line Items] | |||
Costs for services | 29 | 28 | 25 |
Southern Power | Southern Company Gas | |||
Related Party Transaction [Line Items] | |||
Costs for services | 26 | 64 | 119 |
Southern Company Gas | Southern Company Services, Inc. | |||
Related Party Transaction [Line Items] | |||
Costs for services | 237 | 183 | 194 |
Southern Company Gas | Southern Natural Gas Company, LLC | |||
Related Party Transaction [Line Items] | |||
Costs for services | $ 29 | $ 31 | $ 32 |
SUMMARY OF SIGNIFICANT ACCOUN_6
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Affiliate Transactions (Narrative) (Details) - USD ($) | 1 Months Ended | 12 Months Ended | ||
Jan. 31, 2020 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Southern Company Gas | ||||
Related Party Transaction [Line Items] | ||||
Proceeds from affiliate | $ 71,000,000 | |||
Southern Nuclear Operating Company, Inc. | Alabama Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | $ 262,000,000 | $ 256,000,000 | $ 247,000,000 | |
Southern Nuclear Operating Company, Inc. | Georgia Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 883,000,000 | 760,000,000 | 780,000,000 | |
Southern Power | Georgia Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 141,000,000 | 177,000,000 | 216,000,000 | |
Southern Natural Gas Company, LLC | Alabama Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 15,000,000 | 17,000,000 | 8,000,000 | |
Southern Natural Gas Company, LLC | Georgia Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 108,000,000 | 99,000,000 | 101,000,000 | |
Proceeds from affiliate | $ 142,000,000 | |||
Southern Natural Gas Company, LLC | Southern Company Gas | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 29,000,000 | 31,000,000 | 32,000,000 | |
Southern Natural Gas Company, LLC | Southern Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 29,000,000 | 28,000,000 | 25,000,000 | |
Gulf Power | Alabama Power | ||||
Related Party Transaction [Line Items] | ||||
Amounts received related to tariff | 11,000,000 | |||
Gulf Power | Georgia Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 8,000,000 | |||
Gulf Power | Mississippi Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 31,000,000 | |||
PowerSecure International, Inc. | Alabama Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 0 | 7,000,000 | 24,000,000 | |
PowerSecure International, Inc. | Georgia Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 11,000,000 | 0 | 0 | |
Southern Company Services, Inc. | Alabama Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 478,000,000 | 527,000,000 | 508,000,000 | |
Southern Company Services, Inc. | Georgia Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 639,000,000 | 704,000,000 | 653,000,000 | |
Southern Company Services, Inc. | Southern Company Gas | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 237,000,000 | 183,000,000 | 194,000,000 | |
Southern Company Services, Inc. | Mississippi Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 149,000,000 | 118,000,000 | 104,000,000 | |
Southern Company Services, Inc. | Southern Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 87,000,000 | 90,000,000 | 98,000,000 | |
Non-Fuel Expense | Mississippi Power | Alabama Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 9,000,000 | 9,000,000 | 8,000,000 | |
Purchased Power from Affiliates | Southern Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 139,000,000 | 174,000,000 | 215,000,000 | |
Operating Lease PPA | Southern Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | 115,000,000 | 116,000,000 | 65,000,000 | |
Electric Transmission | Southern Company Services, Inc. | Southern Power | ||||
Related Party Transaction [Line Items] | ||||
Costs for services | $ 15,000,000 | $ 15,000,000 | $ 12,000,000 | |
Plant Scherer (coal) Unit 3 | Gulf Power | Georgia Power | ||||
Related Party Transaction [Line Items] | ||||
Proportionate share of related non-fuel expenses (percent) | 25.00% | |||
Plant Daniel | Gulf Power | Georgia Power | ||||
Related Party Transaction [Line Items] | ||||
Proportionate share of related non-fuel expenses (percent) | 50.00% |
SUMMARY OF SIGNIFICANT ACCOUN_7
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Revenues (Narrative) (Details) | 12 Months Ended |
Dec. 31, 2020 | |
Southern Company Gas | |
Disaggregation of Revenue [Line Items] | |
Period for collection of revenue prior to billings | 24 months |
SUMMARY OF SIGNIFICANT ACCOUN_8
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Concentration of Credit Risk (Narrative) (Details) $ in Millions | 12 Months Ended | |
Dec. 31, 2020USD ($)counterpartycustomer | Dec. 31, 2019USD ($) | |
Concentration Risk [Line Items] | ||
Accounts Receivables | $ 2,614 | $ 2,413 |
Southern Company Gas | ||
Concentration Risk [Line Items] | ||
Accounts Receivables | $ 788 | $ 749 |
Atlanta Gas Light | ||
Concentration Risk [Line Items] | ||
Number of customers in Georgia | customer | 16 | |
Percent of highest month's estimated bill | 200.00% | |
Credit Concentration Risk | Wholesale gas services | Accounts Receivable | Southern Company Gas | ||
Concentration Risk [Line Items] | ||
Number of top counterparties | counterparty | 20 | |
Credit risk exposure, measurement period | 30 days | |
Concentration risk (as percent) | 58.00% | |
Accounts Receivables | $ 234 |
SUMMARY OF SIGNIFICANT ACCOUN_9
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Concentration of Revenue (Narrative) (Details) - Mississippi Power | 12 Months Ended |
Dec. 31, 2020 | |
Concentration Risk [Line Items] | |
Wholesale customers representing total operating revenues (percent) | 15.30% |
Period of cancellation notices | 10 years |
SUMMARY OF SIGNIFICANT ACCOU_10
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Concentration of Revenue (Details) - Southern Power - Sales Revenue, Goods, Net - Customer Concentration Risk | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Southern California Edison | |||
Concentration Risk [Line Items] | |||
Percentage of total revenues | 9.40% | 6.80% | 6.20% |
Georgia Power | |||
Concentration Risk [Line Items] | |||
Percentage of total revenues | 8.00% | 9.00% | 9.80% |
Duke Energy Corporation | |||
Concentration Risk [Line Items] | |||
Percentage of total revenues | 6.70% | 6.80% | |
Morgan Stanley Capital Group | |||
Concentration Risk [Line Items] | |||
Percentage of total revenues | 4.90% |
SUMMARY OF SIGNIFICANT ACCOU_11
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Income and Other Taxes (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Southern Power | |||
Tax Credit Carryforward [Line Items] | |||
Percentage reduction in tax basis of assets | 50.00% | ||
Southern Company Gas | |||
Tax Credit Carryforward [Line Items] | |||
Excise taxes collected | $ 107 | $ 117 | $ 114 |
Included In Operating Expenses | Southern Company Gas | |||
Tax Credit Carryforward [Line Items] | |||
Excise taxes collected | $ 104 | $ 114 | $ 111 |
SUMMARY OF SIGNIFICANT ACCOU_12
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Total AFUDC and Interest Capitalized (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Capitalized Contract Cost [Line Items] | |||
Total AFUDC and interest capitalized | $ 230 | $ 202 | $ 210 |
Alabama Power | |||
Capitalized Contract Cost [Line Items] | |||
Total AFUDC and interest capitalized | 61 | 71 | 84 |
Georgia Power | |||
Capitalized Contract Cost [Line Items] | |||
Total AFUDC and interest capitalized | 138 | 103 | 94 |
Mississippi Power | |||
Capitalized Contract Cost [Line Items] | |||
Total AFUDC and interest capitalized | 1 | 0 | 0 |
Southern Power | |||
Capitalized Contract Cost [Line Items] | |||
Total AFUDC and interest capitalized | 11 | 15 | 17 |
Southern Company Gas | |||
Capitalized Contract Cost [Line Items] | |||
Total AFUDC and interest capitalized | $ 18 | $ 13 | $ 14 |
SUMMARY OF SIGNIFICANT ACCOU_13
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Average AFUDC Composite Rates (Details) | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 |
Alabama Power | |||
Capitalized Contract Cost [Line Items] | |||
Composite rate | 8.10% | 8.40% | 8.30% |
Georgia Power | |||
Capitalized Contract Cost [Line Items] | |||
Composite rate | 6.90% | 6.90% | 7.30% |
Mississippi Power | |||
Capitalized Contract Cost [Line Items] | |||
Composite rate | 5.40% | 7.30% | 3.30% |
Atlanta Gas Light | |||
Capitalized Contract Cost [Line Items] | |||
Composite rate | 7.70% | 7.80% | 7.90% |
Chattanooga Gas | |||
Capitalized Contract Cost [Line Items] | |||
Composite rate | 7.10% | 7.10% | 7.40% |
Nicor Gas | |||
Capitalized Contract Cost [Line Items] | |||
Composite rate | 0.70% | 2.30% | 2.10% |
SUMMARY OF SIGNIFICANT ACCOU_14
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Goodwill and Other Intangible Assets and Liabilities (Narrative) (Details) - USD ($) | 3 Months Ended | ||||
Dec. 31, 2020 | Sep. 30, 2019 | Jun. 30, 2019 | Dec. 31, 2019 | Dec. 31, 2018 | |
Finite-Lived Intangible Assets [Line Items] | |||||
Goodwill impairment | $ 0 | ||||
Goodwill | 5,280,000,000 | $ 5,280,000,000 | $ 5,315,000,000 | ||
Intangible liabilities included in other deferred credits and liabilities | 480,000,000 | 609,000,000 | |||
Southern Company Gas | |||||
Finite-Lived Intangible Assets [Line Items] | |||||
Goodwill impairment | 0 | ||||
Goodwill | 5,015,000,000 | 5,015,000,000 | |||
Intangible liabilities included in other deferred credits and liabilities | 54,000,000 | $ 51,000,000 | |||
Intangible liabilities | Southern Company Gas | |||||
Finite-Lived Intangible Assets [Line Items] | |||||
Intangible liabilities included in other deferred credits and liabilities | 91,000,000 | ||||
Disposal Group, Held-for-sale, Not Discontinued Operations | PowerSecure Utility Infrastructure Services Unit | |||||
Finite-Lived Intangible Assets [Line Items] | |||||
Goodwill impairment | $ 32,000,000 | ||||
Disposal Group, Held-for-sale, Not Discontinued Operations | PowerSecure Utility Infrastructure Services Unit | COVID-19 | |||||
Finite-Lived Intangible Assets [Line Items] | |||||
Goodwill | $ 263,000,000 | ||||
Disposal Group, Held-for-sale, Not Discontinued Operations | PowerSecure International, Inc. Lighting Business | |||||
Finite-Lived Intangible Assets [Line Items] | |||||
Goodwill impairment | $ 2,000,000 | ||||
Impairment of intangible assets | $ 3,000,000 |
SUMMARY OF SIGNIFICANT ACCOU_15
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Goodwill Balances (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 |
Goodwill [Line Items] | |||
Goodwill | $ 5,280 | $ 5,280 | $ 5,315 |
Southern Company Gas | |||
Goodwill [Line Items] | |||
Goodwill | 5,015 | 5,015 | |
Gas distribution operations | Southern Company Gas | |||
Goodwill [Line Items] | |||
Goodwill | 4,034 | 4,034 | |
Gas marketing services | Southern Company Gas | |||
Goodwill [Line Items] | |||
Goodwill | $ 981 | $ 981 |
SUMMARY OF SIGNIFICANT ACCOU_16
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Other Intangible Assets (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Finite-Lived Intangible Assets [Line Items] | ||
Gross Carrying Amount | $ 740 | $ 741 |
Accumulated Amortization | (328) | (280) |
Other Intangible Assets, Net | 412 | 461 |
Intangible assets, gross | 815 | 816 |
Intangible assets, net | 487 | 536 |
Federal Communications Commission licenses | ||
Finite-Lived Intangible Assets [Line Items] | ||
Gross Carrying Amount | 75 | 75 |
Accumulated Amortization | 0 | 0 |
Other Intangible Assets, Net | 75 | 75 |
Customer relationships | ||
Finite-Lived Intangible Assets [Line Items] | ||
Gross Carrying Amount | 212 | 212 |
Accumulated Amortization | (135) | (116) |
Other Intangible Assets, Net | 77 | 96 |
Trade names | ||
Finite-Lived Intangible Assets [Line Items] | ||
Gross Carrying Amount | 64 | 64 |
Accumulated Amortization | (31) | (25) |
Other Intangible Assets, Net | 33 | 39 |
Storage and transportation contracts | ||
Finite-Lived Intangible Assets [Line Items] | ||
Gross Carrying Amount | 64 | 64 |
Accumulated Amortization | (64) | (62) |
Other Intangible Assets, Net | 0 | 2 |
PPA fair value adjustments | ||
Finite-Lived Intangible Assets [Line Items] | ||
Gross Carrying Amount | 390 | 390 |
Accumulated Amortization | (89) | (69) |
Other Intangible Assets, Net | 301 | 321 |
Other | ||
Finite-Lived Intangible Assets [Line Items] | ||
Gross Carrying Amount | 10 | 11 |
Accumulated Amortization | (9) | (8) |
Other Intangible Assets, Net | 1 | 3 |
Southern Power | ||
Finite-Lived Intangible Assets [Line Items] | ||
Accumulated Amortization | (89) | (69) |
Southern Power | PPA fair value adjustments | ||
Finite-Lived Intangible Assets [Line Items] | ||
Gross Carrying Amount | 390 | 390 |
Accumulated Amortization | (89) | (69) |
Other Intangible Assets, Net | 301 | 321 |
Southern Company Gas | ||
Finite-Lived Intangible Assets [Line Items] | ||
Gross Carrying Amount | 246 | 246 |
Accumulated Amortization | (195) | (176) |
Other Intangible Assets, Net | 51 | 70 |
Intangible assets, net | 51 | 70 |
Southern Company Gas | Customer relationships | ||
Finite-Lived Intangible Assets [Line Items] | ||
Gross Carrying Amount | 156 | 156 |
Accumulated Amortization | (119) | (104) |
Other Intangible Assets, Net | 37 | 52 |
Southern Company Gas | Trade names | ||
Finite-Lived Intangible Assets [Line Items] | ||
Gross Carrying Amount | 26 | 26 |
Accumulated Amortization | (12) | (10) |
Other Intangible Assets, Net | 14 | 16 |
Southern Company Gas | Storage and transportation contracts | ||
Finite-Lived Intangible Assets [Line Items] | ||
Gross Carrying Amount | 64 | 64 |
Accumulated Amortization | (64) | (62) |
Other Intangible Assets, Net | $ 0 | $ 2 |
SUMMARY OF SIGNIFICANT ACCOU_17
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Amortization of Other Intangible Assets (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Finite-Lived Intangible Assets [Line Items] | |||
Amortization associated with other intangible assets | $ 49 | $ 61 | $ 89 |
Estimated future amortization | |||
2021 | 43 | ||
2022 | 39 | ||
2023 | 37 | ||
2024 | 35 | ||
2025 | 32 | ||
Southern Power | |||
Finite-Lived Intangible Assets [Line Items] | |||
Amortization associated with other intangible assets | 20 | 19 | 25 |
Estimated future amortization | |||
2021 | 20 | ||
2022 | 20 | ||
2023 | 20 | ||
2024 | 20 | ||
2025 | 20 | ||
Southern Company Gas | |||
Finite-Lived Intangible Assets [Line Items] | |||
Amortization associated with other intangible assets | 19 | 31 | 52 |
Estimated future amortization | |||
2021 | 14 | ||
2022 | 11 | ||
2023 | 9 | ||
2024 | 7 | ||
2025 | 6 | ||
Southern Company Gas | Gas marketing services | |||
Finite-Lived Intangible Assets [Line Items] | |||
Amortization associated with other intangible assets | 17 | 23 | 32 |
Southern Company Gas | Wholesale gas services | |||
Finite-Lived Intangible Assets [Line Items] | |||
Amortization associated with other intangible assets | 2 | 8 | 20 |
Operating Revenues | |||
Finite-Lived Intangible Assets [Line Items] | |||
Amortization associated with other intangible assets | $ 22 | $ 27 | $ 45 |
SUMMARY OF SIGNIFICANT ACCOU_18
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Transmission Receivables/Prepayments (Narrative) (Details) | 12 Months Ended |
Dec. 31, 2020 | |
Southern Power | |
Revenue Recognition, Multiple-deliverable Arrangements [Line Items] | |
Period of reimbursement for transmission costs | 5 years |
SUMMARY OF SIGNIFICANT ACCOU_19
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Restricted Cash (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Other Accounts and Notes Receivable | Southern Company Gas | ||
Restricted Cash and Cash Equivalents Items [Line Items] | ||
Restricted cash | $ 2 | $ 3 |
SUMMARY OF SIGNIFICANT ACCOU_20
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Storm Damage Reserves (Details) - Major storms - USD ($) | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Liability for Catastrophe Claims [Line Items] | |||
Storm damage reserves | $ 326,000,000 | $ 170,000,000 | $ 74,000,000 |
Alabama Power | |||
Liability for Catastrophe Claims [Line Items] | |||
Additional accruals authorized by state PSCs | 100,000,000 | 84,000,000 | 0 |
Storm damage reserves | 112,000,000 | 139,000,000 | 16,000,000 |
Georgia Power | |||
Liability for Catastrophe Claims [Line Items] | |||
Storm damage reserves | 213,000,000 | 30,000,000 | 30,000,000 |
Mississippi Power | |||
Liability for Catastrophe Claims [Line Items] | |||
Storm damage reserves | $ 1,000,000 | 1,000,000 | 1,000,000 |
Gulf Power | |||
Liability for Catastrophe Claims [Line Items] | |||
Storm damage reserves | $ 26,900,000 | ||
Accumulated Deferred Income Taxes | Alabama Power | |||
Liability for Catastrophe Claims [Line Items] | |||
Storm damage reserves | $ 39,000,000 |
SUMMARY OF SIGNIFICANT ACCOU_21
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Leveraged Leases (Narrative) (Details) - leveraged_lease | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Leveraged Lease [Line Items] | ||
Number of leveraged leases | 4 | 4 |
Maximum | ||
Leveraged Lease [Line Items] | ||
Original term (up to) | 45 years | 45 years |
SUMMARY OF SIGNIFICANT ACCOU_22
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Net Investment in Domestic and International Leveraged Leases (Details) - Domestic and international leveraged leases - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Leveraged Lease [Line Items] | ||
Net rentals receivable | $ 734 | $ 1,410 |
Unearned income | (178) | (622) |
Investment in leveraged leases | 556 | 788 |
Deferred taxes from leveraged leases | (7) | (238) |
Net investment in leveraged leases | $ 549 | $ 550 |
SUMMARY OF SIGNIFICANT ACCOU_23
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Summary of the Components of Income from Leveraged Leases (Details) - Domestic and international leveraged leases - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Leveraged Lease [Line Items] | |||
Pretax leveraged lease income (loss) | $ (180) | $ 11 | $ 25 |
Income tax benefit (expense) | 98 | 0 | (6) |
Net leveraged lease income (loss) | $ (82) | $ 11 | $ 19 |
SUMMARY OF SIGNIFICANT ACCOU_24
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Natural Gas for Sale (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Nicor Gas | |||
Inventory [Line Items] | |||
LIFO inventory balance | $ 178 | ||
Estimated replacement cost of inventory | 259 | ||
Southern Company Gas | |||
Inventory [Line Items] | |||
LOCOM adjustments | $ 1 | $ 21 | $ 10 |
SUMMARY OF SIGNIFICANT ACCOU_25
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Energy Marketing Receivables and Payables (Narrative) (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Accounting Policies [Abstract] | ||
Required collateral in the event of a credit rating downgrade | $ 5 | $ 11 |
SUMMARY OF SIGNIFICANT ACCOU_26
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Provision for Uncollectible Accounts (Narrative) (Details) | 12 Months Ended |
Dec. 31, 2020 | |
Accounting Policies [Abstract] | |
Uncollectible accounts, average percent of revenues (less than) | 1.00% |
SUMMARY OF SIGNIFICANT ACCOU_27
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Financial Instruments (Narrative) (Details) | Dec. 31, 2020USD ($) |
Alabama Power | |
Derivative [Line Items] | |
Derivative collateral obligation to return cash | $ 0 |
SUMMARY OF SIGNIFICANT ACCOU_28
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of AOCI (Loss) Balances, Net of Tax Effects (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Beginning balance | $ 31,759 | $ 29,039 | $ 25,528 |
Current period change | (75) | (118) | 26 |
Ending balance | 32,234 | 31,759 | 29,039 |
Qualifying Hedges | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Beginning balance | (179) | ||
Current period change | (30) | ||
Ending balance | (209) | (179) | |
Pension and Other Postretirement Benefit Plans | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Beginning balance | (142) | ||
Current period change | (45) | ||
Ending balance | (187) | (142) | |
Accumulated Other Comprehensive Income (Loss) | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Beginning balance | (321) | (203) | (189) |
Current period change | (75) | ||
Ending balance | (395) | (321) | (203) |
Southern Power | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Beginning balance | 6,622 | 7,284 | 6,498 |
Current period change | (42) | (42) | 14 |
Ending balance | 6,631 | 6,622 | 7,284 |
Southern Power | Qualifying Hedges | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Beginning balance | 11 | ||
Current period change | (32) | ||
Ending balance | (21) | 11 | |
Southern Power | Pension and Other Postretirement Benefit Plans | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Beginning balance | (37) | ||
Current period change | (10) | ||
Ending balance | (47) | (37) | |
Southern Power | Accumulated Other Comprehensive Income (Loss) | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Beginning balance | (26) | 16 | (2) |
Current period change | (42) | ||
Ending balance | (67) | (26) | 16 |
Southern Company Gas | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Beginning balance | 9,506 | 8,570 | 9,022 |
Current period change | (29) | (19) | 2 |
Ending balance | 9,767 | 9,506 | 8,570 |
Southern Company Gas | Qualifying Hedges | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Beginning balance | (6) | ||
Current period change | (14) | ||
Ending balance | (20) | (6) | |
Southern Company Gas | Pension and Other Postretirement Benefit Plans | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Beginning balance | 13 | ||
Current period change | (15) | ||
Ending balance | (2) | 13 | |
Southern Company Gas | Accumulated Other Comprehensive Income (Loss) | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Beginning balance | 7 | 26 | 20 |
Current period change | (29) | ||
Ending balance | $ (22) | $ 7 | $ 26 |
REGULATORY MATTERS - Schedule o
REGULATORY MATTERS - Schedule of Regulatory Assets and Liabilities (Details) - USD ($) $ in Millions | Mar. 17, 2020 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 |
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 5,493 | $ 3,838 | ||
Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 1,481 | 810 | ||
Alabama Power | Maximum | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 28 years | |||
Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 4,252 | 3,507 | ||
Costs recovered annually | 12 | 2 | $ 2 | |
Recoveries for storm damage | $ 213 | |||
Georgia Power | Maximum | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 32 years | |||
Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 136 | 64 | ||
Regulatory asset amortization period | 4 years | |||
Regulatory liability amortization period | 3 years | |||
Mississippi Power | Maximum | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 8 years | |||
Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ (1,925) | (1,874) | ||
Southern Company Gas | Maximum | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 7 years | |||
Deferred Income Tax Credits | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ (6,016) | (6,301) | ||
Deferred Income Tax Credits | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | (2,016) | (1,960) | ||
Deferred Income Tax Credits | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | (2,805) | (3,078) | ||
Deferred Income Tax Credits | Georgia Power | Plant Vogtle Units 3 And 4 | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory liabilities | 440 | |||
Deferred Income Tax Credits | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | (320) | (358) | ||
Regulatory liabilities | 74 | |||
Deferred Income Tax Credits | Mississippi Power | Retail electric revenues | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory liabilities | $ 66 | |||
Regulatory liability amortization period | 3 years | |||
Deferred Income Tax Credits | Mississippi Power | Wholesale electric revenues | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory liabilities | $ 9 | |||
Regulatory liability amortization period | 2 years | |||
Deferred Income Tax Credits | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ (847) | (874) | ||
Other Cost of Removal Obligations | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | (1,999) | (2,084) | ||
Other Cost of Removal Obligations | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | (335) | (412) | ||
Other Cost of Removal Obligations | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 212 | 156 | ||
Other Cost of Removal Obligations | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | (194) | (189) | ||
Other Cost of Removal Obligations | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | (1,649) | (1,606) | ||
Over Recovered Regulatory Clause Revenues | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | (185) | (205) | ||
Over Recovered Regulatory Clause Revenues | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ (46) | (112) | ||
Regulatory liability amortization period | 9 years | |||
Over Recovered Regulatory Clause Revenues | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ (44) | (10) | ||
Regulatory liability amortization period | 2 years | |||
Over Recovered Regulatory Clause Revenues | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 0 | 0 | ||
Over Recovered Regulatory Clause Revenues | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ (95) | (82) | ||
Regulatory liability amortization period | 5 years | |||
Storm/Property Damage Reserves | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ (81) | (204) | ||
Storm/Property Damage Reserves | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | (77) | (150) | ||
Storm/Property Damage Reserves | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Storm/Property Damage Reserves | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | (4) | (55) | ||
Storm/Property Damage Reserves | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Customer Refunds | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | (56) | (285) | ||
Customer Refunds | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | (50) | (56) | ||
Regulatory liabilities | 50 | 53 | ||
Customer Refunds | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | (6) | (229) | ||
Regulatory liabilities | 110 | |||
Customer Refunds | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Customer Refunds | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Other Regulatory Liabilities | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | (149) | (70) | ||
Other Regulatory Liabilities | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ (37) | (19) | ||
Regulatory liability amortization period | 17 years | |||
Other Regulatory Liabilities | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ (30) | (6) | ||
Regulatory liability amortization period | 12 years | |||
Other Regulatory Liabilities | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ (6) | (10) | ||
Regulatory liability amortization period | 3 years | |||
Other Regulatory Liabilities | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ (54) | (22) | ||
Regulatory liability amortization period | 20 years | |||
Excess Deferred Income Tax Liabilities Not Subject To Normalization | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 8 | |||
Tax Reform Settlement Agreement | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory liabilities | 105 | |||
AROs | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 5,147 | 4,381 | ||
AROs | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 1,470 | 1,043 | ||
AROs | Alabama Power | Maximum | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 53 years | |||
AROs | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 3,457 | 3,119 | ||
AROs | Georgia Power | Maximum | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 60 years | |||
AROs | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 212 | 210 | ||
AROs | Mississippi Power | Maximum | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 55 years | |||
AROs | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 0 | 0 | ||
AROs | Southern Company Gas | Maximum | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 80 years | |||
Retiree Benefit Plans | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 4,958 | 4,423 | ||
Retiree Benefit Plans | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 1,265 | 1,131 | ||
Retiree Benefit Plans | Alabama Power | Maximum | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 13 years | |||
Retiree Benefit Plans | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 1,647 | 1,516 | ||
Retiree Benefit Plans | Georgia Power | Maximum | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 13 years | |||
Retiree Benefit Plans | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 238 | 213 | ||
Retiree Benefit Plans | Mississippi Power | Maximum | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 14 years | |||
Retiree Benefit Plans | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 187 | 167 | ||
Retiree Benefit Plans | Southern Company Gas | Maximum | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 13 years | |||
Remaining Net Book Value of Retired Assets | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 1,183 | 1,275 | ||
Remaining Net Book Value of Retired Assets | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 632 | 649 | ||
Remaining Net Book Value of Retired Assets | Alabama Power | Plant Gorgas Units 8, 9, And 10 | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 585 | |||
Remaining Net Book Value of Retired Assets | Alabama Power | Maximum | Plant Gorgas Units 8, 9, And 10 | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 17 years | |||
Remaining Net Book Value of Retired Assets | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 527 | $ 596 | ||
Remaining Net Book Value of Retired Assets | Georgia Power | Plant Hammond Units 1 - 4 and Plant Branch Units 2 - 4 | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 503 | |||
Remaining Net Book Value of Retired Assets | Georgia Power | Plant McIntosh Unit 1 and Plant Mitchell Unit 3 | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 24 | |||
Remaining Net Book Value of Retired Assets | Georgia Power | Maximum | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 3 years | |||
Remaining Net Book Value of Retired Assets | Georgia Power | Maximum | Plant Hammond Units 1 - 4 and Plant Branch Units 2 - 4 | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 15 years | |||
Remaining Net Book Value of Retired Assets | Georgia Power | Minimum | Plant Hammond Units 1 - 4 and Plant Branch Units 2 - 4 | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 2 years | |||
Remaining Net Book Value of Retired Assets | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 24 | $ 30 | ||
Remaining Net Book Value of Retired Assets | Mississippi Power | Plant Watson and Plant Greene County | Retail electric revenues | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 11 | |||
Regulatory asset amortization period | 4 years | |||
Remaining Net Book Value of Retired Assets | Mississippi Power | Plant Watson and Plant Greene County | Wholesale electric revenues | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 13 | |||
Regulatory asset amortization period | 10 years | |||
Remaining Net Book Value of Retired Assets | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 0 | 0 | ||
Deferred Income Tax Charges | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 801 | 803 | ||
Deferred Income Tax Charges | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 235 | 245 | ||
Deferred Income Tax Charges | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 531 | 523 | ||
Deferred Income Tax Charges | Georgia Power | Plant Vogtle Units 3 And 4 | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset | 145 | |||
Deferred Income Tax Charges | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 32 | 33 | ||
Deferred Income Tax Charges | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Environmental Remediation | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 310 | 349 | ||
Environmental Remediation | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Environmental Remediation | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 41 | 52 | ||
Environmental Remediation | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Environmental Remediation | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 269 | 296 | ||
Loss on Reacquired Debt | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 304 | 323 | ||
Loss on Reacquired Debt | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 47 | 52 | ||
Loss on Reacquired Debt | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 248 | 262 | ||
Loss on Reacquired Debt | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 6 | 6 | ||
Loss on Reacquired Debt | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 3 | 4 | ||
Storm Damage | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 262 | 410 | ||
Storm Damage | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Storm Damage | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 262 | 410 | ||
Storm Damage | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Storm Damage | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Vacation Pay | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 207 | 186 | ||
Regulatory asset amortization period | 1 year | |||
Vacation Pay | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 80 | 72 | ||
Vacation Pay | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 104 | 93 | ||
Vacation Pay | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 10 | 9 | ||
Vacation Pay | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 13 | 11 | ||
Under Recovered Regulatory Clause Revenues | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 185 | 159 | ||
Under Recovered Regulatory Clause Revenues | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 58 | 40 | ||
Regulatory asset amortization period | 9 years | |||
Under Recovered Regulatory Clause Revenues | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 0 | 0 | ||
Regulatory asset amortization period | 2 years | |||
Under Recovered Regulatory Clause Revenues | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 52 | 47 | ||
Under Recovered Regulatory Clause Revenues | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 75 | 72 | ||
Regulatory asset amortization period | 5 years | |||
Regulatory Clauses | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 142 | 142 | ||
Regulatory Clauses | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 142 | 142 | ||
Regulatory Clauses | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Regulatory Clauses | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Regulatory Clauses | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Nuclear Outage | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 101 | 105 | ||
Nuclear Outage | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 61 | 78 | ||
Regulatory asset amortization period | 18 months | |||
Nuclear Outage | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 40 | 27 | ||
Nuclear Outage | Georgia Power | Maximum | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 24 months | |||
Nuclear Outage | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 0 | 0 | ||
Nuclear Outage | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 0 | 0 | ||
Fuel Hedging (Realized And Unrealized) Losses | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 102 | |||
Fuel Hedging (Realized And Unrealized) Losses | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 22 | |||
Regulatory asset amortization period | 3 years 6 months | |||
Fuel Hedging (Realized And Unrealized) Losses | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 53 | |||
Regulatory asset amortization period | 3 years | |||
Fuel Hedging (Realized And Unrealized) Losses | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 27 | |||
Regulatory asset amortization period | 5 years | |||
Fuel Hedging (Realized And Unrealized) Losses | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | |||
Long Term Debt Fair Value Adjustment | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 92 | 107 | ||
Long Term Debt Fair Value Adjustment | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Long Term Debt Fair Value Adjustment | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Long Term Debt Fair Value Adjustment | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Long Term Debt Fair Value Adjustment | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 92 | 107 | ||
Long Term Debt Fair Value Adjustment | Southern Company Gas | Maximum | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 18 years | |||
Kemper County energy facility assets, net | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 50 | 61 | ||
Kemper County energy facility assets, net | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Kemper County energy facility assets, net | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Kemper County energy facility assets, net | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 50 | 61 | ||
Regulatory asset | 62 | |||
Regulatory liabilities | 12 | |||
Kemper County energy facility assets, net | Mississippi Power | Retail electric revenues | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset | 50 | |||
Regulatory liabilities | 12 | |||
Kemper County energy facility assets, net | Mississippi Power | Wholesale electric revenues | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset | 12 | |||
Kemper County energy facility assets, net | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Plant Daniel Units 3 and 4 | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 32 | 34 | ||
Plant Daniel Units 3 and 4 | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Plant Daniel Units 3 and 4 | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Plant Daniel Units 3 and 4 | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 32 | 34 | ||
Plant Daniel Units 3 and 4 | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 0 | 0 | ||
Other Regulatory Assets | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 205 | 127 | ||
Other Regulatory Assets | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 52 | 45 | ||
Regulatory asset amortization period | 23 years | |||
Other Regulatory Assets | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 68 | 23 | ||
Regulatory asset amortization period | 3 years | |||
Other Regulatory Assets | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 4 | 6 | ||
Regulatory asset amortization period | 4 years | |||
Other Regulatory Assets | Southern Company Gas | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 81 | $ 53 | ||
Regulatory asset amortization period | 20 years | |||
CCR AROs | Georgia Power | Maximum | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Regulatory asset amortization period | 3 years | |||
Retiree Medicare Drug Subsidy | Alabama Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 8 | |||
Retiree Medicare Drug Subsidy | Georgia Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 9 | |||
Retiree Medicare Drug Subsidy | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | 1 | |||
Regulatory Clauses, Amortized Through PEP | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 37 | |||
Regulatory asset amortization period | 4 years | |||
Ad Valorem Tax Adjustment Clause | Mississippi Power | ||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||
Total regulatory assets (liabilities), net | $ 15 |
REGULATORY MATTERS - APC Petiti
REGULATORY MATTERS - APC Petition for Certificate of Convenience and Necessity (Details) $ in Millions | Dec. 31, 2020USD ($)MW | Aug. 14, 2020USD ($)MW | Dec. 31, 2019USD ($)MW |
Schedule of Regulatory Assets and Liabilities [Line Items] | |||
Construction work in progress | $ | $ 8,697 | $ 7,880 | |
Alabama Power | |||
Schedule of Regulatory Assets and Liabilities [Line Items] | |||
Approved additional generating capacity, demand-side management and distributed energy resource programs | 200 | ||
Additional generating capacity, petitioned megawatts, total | 2,400 | ||
Construction work in progress | $ | $ 866 | $ 890 | |
Alabama Power | Year 2020 | |||
Schedule of Regulatory Assets and Liabilities [Line Items] | |||
PPA, additional generating capacity (in MWs) | 240 | ||
Alabama Power | Years 2022 Through 2024 | |||
Schedule of Regulatory Assets and Liabilities [Line Items] | |||
PPA, additional generating capacity (in MWs) | 400 | ||
Plant Barry Unit 8 | Alabama Power | |||
Schedule of Regulatory Assets and Liabilities [Line Items] | |||
Approximate nameplate capacity (in MW) | 720 | ||
Costs incurred, percentage of estimated in-service cost | 5.00% | ||
Estimated in-service cost | $ | $ 652 | ||
Construction work in progress | $ | $ 66 |
REGULATORY MATTERS - APC Rate R
REGULATORY MATTERS - APC Rate RSE (Details) - Alabama Power - USD ($) $ in Millions | 1 Months Ended | 12 Months Ended | ||||||
Jan. 31, 2019 | Dec. 31, 2025 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 01, 2020 | Aug. 07, 2020 | Feb. 28, 2019 | Dec. 31, 2018 | |
Public Utilities, General Disclosures [Line Items] | ||||||||
Rate adjustment period | 2 years | |||||||
Maximum percentage of rate RSE | 4.00% | |||||||
Maximum annual percentage of ratio rate | 5.00% | |||||||
Adjusting point of weighted cost of equity | 5.98% | |||||||
Percent of basis points | 0.07% | |||||||
Percent of designated customer value benchmark survey | 33.33% | |||||||
Authorized ROE | 51.60% | 50.30% | ||||||
Weighted common equity return | 6.15% | 6.21% | ||||||
Customer refundable fees, refund payments, tranche one, percentage | 25.00% | |||||||
Customer refundable fees, refund payments, tranche two, percentage | 40.00% | |||||||
Customer refundable fees, refund payments, tranche two, percentage | 75.00% | |||||||
Customer refundable fees, refund payments, tranche one, review year with rate RSE upward adjustment, percentage | 50.00% | |||||||
Contract with customer, liability, bill credits | $ 50 | $ 100 | $ 267 | |||||
Rate RSE refund liability | $ 50 | $ 53 | $ 78 | |||||
Rate RSE increase | 4.09% | |||||||
Rate RSE increase amount | $ 228 | |||||||
Revenue Subject to Refund | ||||||||
Public Utilities, General Disclosures [Line Items] | ||||||||
Regulatory liabilities | $ 109 | |||||||
Rate ECR refunds | ||||||||
Public Utilities, General Disclosures [Line Items] | ||||||||
Contract with customer, liability, bill credits | $ 31 | |||||||
Minimum | ||||||||
Public Utilities, General Disclosures [Line Items] | ||||||||
Public utilities, actual weighted common equity return, threshold, percentage | 6.15% | |||||||
Public utilities, actual weighted common equity return, threshold for customer refundable fees, refund payments, percentage, tranche one | 6.15% | 6.15% | ||||||
Public utilities, actual weighted common equity return, threshold for customer refundable fees, refund payments, percentage, tranche two | 6.65% | |||||||
Public utilities, actual weighted common equity return, threshold for customer refundable fees, refund payments, percentage, tranche three | 7.15% | |||||||
Public utilities, actual weighted common equity return, threshold, review year with rate RSE upward adjustment, percentage | 6.15% | |||||||
Public utilities, actual weighted common equity return, threshold for customer refundable fees, refund payments, review year with rate RSE upward adjustment, percentage, tranche one | 6.15% | |||||||
Maximum | ||||||||
Public Utilities, General Disclosures [Line Items] | ||||||||
Public utilities, actual weighted common equity return, threshold, percentage | 7.65% | |||||||
Public utilities, actual weighted common equity return, threshold for customer refundable fees, refund payments, percentage, tranche one | 6.65% | |||||||
Public utilities, actual weighted common equity return, threshold for customer refundable fees, refund payments, percentage, tranche two | 7.15% | |||||||
Public utilities, actual weighted common equity return, threshold for customer refundable fees, refund payments, percentage, tranche three | 7.65% | |||||||
Customer refundable fees, refund payments, percentage | 7.65% | |||||||
Public utilities, actual weighted common equity return, threshold for customer refundable fees, refund payments, review year with rate RSE upward adjustment, percentage, tranche one | 6.90% | |||||||
Customer refundable fees, refund payments, review year with rate RSE upward adjustment, percentage | 6.90% | |||||||
Scenario, Forecast | ||||||||
Public Utilities, General Disclosures [Line Items] | ||||||||
Authorized ROE | 55.00% |
REGULATORY MATTERS - APC Rate C
REGULATORY MATTERS - APC Rate CNP (Details) - Alabama Power - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Schedule of Regulatory Assets and Liabilities [Line Items] | |||
Under recovered certified power purchase agreements | $ 58 | $ 40 | |
Retail revenue requirement for environmental compliance | 59 | 68 | $ 205 |
Over (under) recovered environmental clause | $ 28 | 62 | |
Regulatory Liabilities, Current | |||
Schedule of Regulatory Assets and Liabilities [Line Items] | |||
Over (under) recovered environmental clause | 55 | ||
Regulatory Liabilities, Noncurrent | |||
Schedule of Regulatory Assets and Liabilities [Line Items] | |||
Over (under) recovered environmental clause | $ 7 |
REGULATORY MATTERS - APC Rate E
REGULATORY MATTERS - APC Rate ERC (Details) - Alabama Power $ in Millions | Dec. 01, 2020USD ($)$ / KWH_Kilowatt_hour | Apr. 30, 2018$ / KWH_Kilowatt_hour | Jan. 31, 2022$ / KWH_Kilowatt_hour | Oct. 31, 2020USD ($) | Dec. 31, 2019USD ($)$ / KWH_Kilowatt_hour | May 31, 2018$ / KWH_Kilowatt_hour | Dec. 31, 2020USD ($)$ / KWH_Kilowatt_hour | Aug. 07, 2020USD ($) | Feb. 28, 2019USD ($) | Dec. 31, 2018USD ($) |
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||||||||
Current billing rates under rate ECR (usd per KWH) | $ / KWH_Kilowatt_hour | 1.960 | 0.02015 | 0.02160 | 0.02353 | 0.05910 | |||||
Rate RSE refund liability | $ 53 | $ 50 | $ 78 | |||||||
Current billing rates under rate ECR, percentage decrease | 1.84% | 1.82% | ||||||||
Current billing rates under rate ECR, decrease, amount | $ 103 | $ 102 | ||||||||
Reduction of over-collected fuel balance | $ 94.3 | |||||||||
Contract with customer, liability, bill credits | 50 | $ 100 | $ 267 | |||||||
Over (under) recovered fuel cost | 49 | $ 18 | ||||||||
Other regulatory liabilities, current | ||||||||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||||||||
Over (under) recovered fuel cost | 32 | |||||||||
Other regulatory liabilities, deferred | ||||||||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||||||||
Over (under) recovered fuel cost | $ 17 | |||||||||
Scenario, Forecast | ||||||||||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||||||||||
Current billing rates under rate ECR (usd per KWH) | $ / KWH_Kilowatt_hour | 0.05910 |
REGULATORY MATTERS - APC Accoun
REGULATORY MATTERS - APC Accounting Orders and Plant Greene County (Details) | 1 Months Ended | 12 Months Ended | ||
Dec. 31, 2019USD ($) | Dec. 31, 2020USD ($) | Dec. 31, 2018USD ($) | Dec. 17, 2020MW | |
Public Utilities, General Disclosures [Line Items] | ||||
Other deferred charges and assets | $ 15,469,000,000 | $ 16,298,000,000 | ||
Alabama Power | ||||
Public Utilities, General Disclosures [Line Items] | ||||
Tax Cuts and Jobs Act of 2017, change in tax rate, deferred tax liability, income tax benefit, maximum amount used to offset under recovered amounts | $ 30,000,000 | |||
Tax Cuts and Jobs Act of 2017, change in tax rate, deferred tax liability, income tax benefit | 69,000,000 | |||
Amount offset under recovered balance | 30,000,000 | |||
Tax Cuts and Jobs Act of 2017, change in tax rate, deferred tax liability, income tax benefit, amount increasing NDR balance | 39,000,000 | |||
Other deferred charges and assets | 3,680,000,000 | 4,262,000,000 | ||
Alabama Power | Software Accounting Order | ||||
Public Utilities, General Disclosures [Line Items] | ||||
Other deferred charges and assets | 6,000,000 | 17,000,000 | ||
Mississippi Power | ||||
Public Utilities, General Disclosures [Line Items] | ||||
Other deferred charges and assets | $ 775,000,000 | $ 805,000,000 | ||
Required fossil-stream generation retirements (in MWs) | MW | 950 | |||
Mississippi Power | Plant Greene County Units 1 And 2 | ||||
Public Utilities, General Disclosures [Line Items] | ||||
Alternative accelerated retirement period | 4 years | 4 years |
REGULATORY MATTERS - APC Rate N
REGULATORY MATTERS - APC Rate NDR (Details) - USD ($) | Jan. 01, 2021 | Dec. 31, 2020 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Mar. 31, 2020 |
Major storms | ||||||
Public Utilities, General Disclosures [Line Items] | ||||||
Storm damage reserves | $ 326,000,000 | $ 170,000,000 | $ 74,000,000 | |||
Alabama Power | ||||||
Public Utilities, General Disclosures [Line Items] | ||||||
Minimum natural disaster reserve balance, triggering establishment charge | $ 50,000,000 | 50,000,000 | ||||
Natural disaster reserve authorized limit | 75,000,000 | $ 75,000,000 | $ 75,000,000 | |||
Maximum period for recovery deferred stock related operations and maintenance costs and any future reserve deficits | 24 months | |||||
Maximum rate NDR charge per month, monthly nonresidential customer account | 10 | $ 10 | ||||
Maximum rate NDR charge per month, monthly residential customer account | 5 | 5 | ||||
Annual recovery amount | 5,000,000 | 16,000,000 | 16,000,000 | |||
Alabama Power | Scenario, Forecast | ||||||
Public Utilities, General Disclosures [Line Items] | ||||||
Natural disaster reserve authorized limit | $ 50,000,000 | |||||
Annual recovery amount | $ 3,000,000 | |||||
Alabama Power | Major storms | ||||||
Public Utilities, General Disclosures [Line Items] | ||||||
Additional accruals authorized by state PSCs | 100,000,000 | 84,000,000 | 0 | |||
Storm damage reserves | 112,000,000 | 139,000,000 | $ 16,000,000 | |||
Regulatory asset, amortization period | 113,000,000 | 113,000,000 | 150,000,000 | |||
Alabama Power | Major storms | Other regulatory liabilities, current | ||||||
Public Utilities, General Disclosures [Line Items] | ||||||
Regulatory asset, amortization period | 37,000,000 | 37,000,000 | ||||
Alabama Power | Major storms | Accumulated Deferred Income Taxes | ||||||
Public Utilities, General Disclosures [Line Items] | ||||||
Storm damage reserves | $ 39,000,000 | |||||
Alabama Power | Hurricane Sally And Zeta | Other regulatory liabilities, current | ||||||
Public Utilities, General Disclosures [Line Items] | ||||||
Regulatory asset, amortization period | 77,000,000 | $ 77,000,000 | ||||
Alabama Power | Hurricane Sally | ||||||
Public Utilities, General Disclosures [Line Items] | ||||||
Storm damage reserves | 51,000,000 | |||||
Alabama Power | Hurricane Zeta | ||||||
Public Utilities, General Disclosures [Line Items] | ||||||
Storm damage reserves | $ 67,000,000 |
REGULATORY MATTERS - GPC Regula
REGULATORY MATTERS - GPC Regulatory Matters - Tariffs (Details) - Georgia Power $ in Millions | Dec. 31, 2019USD ($) |
Public Utilities, General Disclosures [Line Items] | |
Rate increase 2020 | $ 342 |
Rate increase 2021 | 111 |
Traditional base | |
Public Utilities, General Disclosures [Line Items] | |
Rate increase 2020 | 0 |
Rate increase 2021 | 120 |
ECCR | |
Public Utilities, General Disclosures [Line Items] | |
Rate increase 2020 | 318 |
Rate increase 2021 | 2 |
DSM | |
Public Utilities, General Disclosures [Line Items] | |
Rate increase 2020 | 12 |
Rate increase 2021 | (15) |
MFF | |
Public Utilities, General Disclosures [Line Items] | |
Rate increase 2020 | 12 |
Rate increase 2021 | $ 4 |
REGULATORY MATTERS - GPC Rate P
REGULATORY MATTERS - GPC Rate Plans and COVID-19 Costs (Details) - Georgia Power - USD ($) $ in Millions | Sep. 17, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2013 | Oct. 31, 2020 | Jun. 30, 2020 |
Public Utilities, General Disclosures [Line Items] | |||||||
Retail rate of return on common equity | 10.50% | 10.95% | |||||
Portion of actual earnings above approved ROE band applied to reduce regulatory assets (percent) | 40.00% | ||||||
Portion of actual earnings above approved ROE band retained by subsidiary company | 20.00% | ||||||
Portion of actual earnings above approved ROE band refunded to customers | 40.00% | 50.00% | 50.00% | 66.67% | |||
Portion of actual earnings above approved ROE band retained by Georgia Power | 33.33% | ||||||
Portion of actual earnings above approved ROE band refunded to customers, used to reduce regulatory assets | 50.00% | 50.00% | |||||
Portion of actual earning above approved ROE band refunded to customers, used to reduce regulatory assets, value | $ 60 | $ 50 | |||||
Portion of actual earnings above approved ROE band refunded to customers, value | 50 | $ 60 | $ 60 | $ 50 | |||
Customer refund liability in absence of base rate case | 110 | ||||||
Incremental COVID-19 costs deferred | $ 38 | ||||||
Customer Refunds | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Portion of actual earnings above approved ROE band refunded to customers, value | $ 110 | ||||||
Maximum | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Regulatory asset amortization period | 32 years | ||||||
Retail rate of return on common equity | 12.00% | 12.00% | |||||
Maximum | Remaining Net Book Value of Retired Assets | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Regulatory asset amortization period | 3 years | ||||||
Minimum | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Retail rate of return on common equity | 9.50% | 10.00% |
REGULATORY MATTERS - GPC Fuel C
REGULATORY MATTERS - GPC Fuel Cost and Storm Damage Recovery (Details) - USD ($) $ in Millions | May 28, 2020 | Sep. 30, 2020 | Dec. 31, 2020 | Oct. 31, 2020 | Dec. 31, 2019 |
Public Utilities, General Disclosures [Line Items] | |||||
Net regulatory assets | $ 5,493 | $ 3,838 | |||
Other regulatory assets | 810 | 885 | |||
Other regulatory assets, deferred | 7,198 | 6,805 | |||
Georgia Power | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Approved decrease in annual billing based on fuel cost recovery rate | $ 740 | ||||
Approved decrease in annual billing based on fuel cost recovery rate, term | 2 years | ||||
Requested rate decrease, amount | $ 44 | ||||
Adjustment to fuel cost recovery rate if under recovered fuel balance exceeds budget thereafter | 200 | ||||
Over recovered fuel balance | $ 113 | 73 | |||
Required period for options and hedges | 36 months | ||||
Recoveries for storm damage | $ 213 | ||||
Net regulatory assets | 4,252 | 3,507 | |||
Other regulatory assets | 248 | 263 | |||
Other regulatory assets, deferred | 2,692 | 2,716 | |||
Georgia Power | Storm damage reserves | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Net regulatory assets | 262 | 410 | |||
Incremental restoration costs | $ 50 | ||||
Georgia Power | Storm/Property Damage Reserves | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Other regulatory assets | 213 | ||||
Other regulatory assets, deferred | $ 49 | $ 197 |
REGULATORY MATTERS - GPC Nuclea
REGULATORY MATTERS - GPC Nuclear Construction (Details) $ in Millions | Dec. 31, 2020USD ($) | Jun. 30, 2020USD ($) | Apr. 30, 2020 | Dec. 31, 2020USD ($) | Dec. 31, 2019USD ($) | Dec. 31, 2018USD ($) | Dec. 31, 2012utilityMW | Jun. 30, 2018USD ($) |
Public Utilities, General Disclosures [Line Items] | ||||||||
Estimated loss on Plant Vogtle Units 3 and 4 | $ 325 | $ 0 | $ 1,060 | |||||
Georgia Power | ||||||||
Public Utilities, General Disclosures [Line Items] | ||||||||
Number of construction units approved | utility | 2 | |||||||
Electric generating capacity (in MWs) | MW | 1,100 | |||||||
Estimated loss on Plant Vogtle Units 3 and 4 | $ 325 | $ 0 | $ 1,060 | |||||
Plant Vogtle Units 3 And 4 | Georgia Power | ||||||||
Public Utilities, General Disclosures [Line Items] | ||||||||
Percent ownership | 45.70% | 45.70% | ||||||
Estimated construction financing costs | $ 3,000 | $ 3,000 | ||||||
Construction financing costs incurred to date | 2,600 | 2,600 | ||||||
Construction contingency estimate, subject to rate recovery evaluation | $ 366 | |||||||
Estimated cost to complete, amount in excess of initial construction contingency estimate | 171 | 171 | $ 34 | |||||
Estimated cost to complete, additional construction contingency estimate | 5 | $ 5 | $ 115 | |||||
Estimated loss on Plant Vogtle Units 3 and 4, net of tax | 131 | 111 | ||||||
Estimated loss on Plant Vogtle Units 3 and 4 | 176 | $ 149 | ||||||
Expected number of positions reduced, percent | 20.00% | |||||||
Plant Vogtle Units 3 And 4 | Georgia Power | Minimum | COVID-19 | ||||||||
Public Utilities, General Disclosures [Line Items] | ||||||||
Estimated months of productivity loss | 3 months | |||||||
Construction financing costs | 150 | $ 150 | ||||||
Plant Vogtle Units 3 And 4 | Georgia Power | Maximum | COVID-19 | ||||||||
Public Utilities, General Disclosures [Line Items] | ||||||||
Estimated months of productivity loss | 4 months | |||||||
Construction financing costs | $ 190 | $ 190 | ||||||
Plant Vogtle Units 3 And 4 | Georgia Power | Vogtle Owners | ||||||||
Public Utilities, General Disclosures [Line Items] | ||||||||
Period of notice required in the event letters of credit are not renewed | 30 days |
REGULATORY MATTERS - GPC Schedu
REGULATORY MATTERS - GPC Schedule of Nuclear Construction Cost and Schedule (Details) - USD ($) $ in Millions | 6 Months Ended | 12 Months Ended | ||
Jun. 30, 2020 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Commitments [Line Items] | ||||
Total AFUDC and interest capitalized | $ 230 | $ 202 | $ 210 | |
Georgia Power | ||||
Commitments [Line Items] | ||||
Total AFUDC and interest capitalized | 138 | $ 103 | $ 94 | |
Georgia Power | Plant Vogtle Units 3 And 4 | ||||
Commitments [Line Items] | ||||
Base project capital cost forecast | 8,500 | |||
Construction contingency estimate | 200 | |||
Total project capital cost forecast | 8,700 | |||
Net investment | (7,200) | |||
Remaining estimate to complete | 1,500 | |||
Total AFUDC and interest capitalized | 246 | |||
Total AFUDC and interest capitalized, accrual amount | 93 | |||
Georgia Power | Plant Vogtle Unit | ||||
Commitments [Line Items] | ||||
Additional base capital costs per month | 25 | |||
Georgia Power | Plant Watson Unit 4 | ||||
Commitments [Line Items] | ||||
Additional base capital costs per month | $ 15 | |||
Twenty Third Vogtle Construction Monitoring Report | Georgia Power | Plant Vogtle Units 3 And 4 | ||||
Commitments [Line Items] | ||||
Maximum guarantee | $ 1,700 | |||
Customer refund | $ 188 |
REGULATORY MATTERS - GPC Amendm
REGULATORY MATTERS - GPC Amendments to the Vogtle Joint Ownership Agreements (Details) - Plant Vogtle Units 3 And 4 - Georgia Power - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2015 | Aug. 31, 2018 | |
Public Utilities, General Disclosures [Line Items] | |||
Production tax credits, aggregate purchase price (up to) | $ 300 | ||
Preliminary estimated cost to complete | $ 8,700 | ||
Additional construction capital costs | $ 3,300 | ||
Remaining share of construction costs, agreement to pay, percentage | 100.00% | ||
Ownership interest percentage required for voting for continuing construction | 90.00% | ||
Percentage of costs, disallowed for recovery | 6.00% | ||
Costs disallowed for recovery, period | 6 months | ||
Public utilities, extension project schedule, term | 1 year | ||
Category I | |||
Public Utilities, General Disclosures [Line Items] | |||
Preliminary estimated cost to complete | $ 8,400 | ||
Additional construction capital costs, threshold | $ 800 | ||
Category II | |||
Public Utilities, General Disclosures [Line Items] | |||
Percentage of construction costs responsible to pay | 55.70% | ||
Additional construction capital costs | $ 80 | ||
Category II | Vogtle Owners | |||
Public Utilities, General Disclosures [Line Items] | |||
Percentage of construction costs responsible to pay | 44.30% | ||
Category II | Minimum | |||
Public Utilities, General Disclosures [Line Items] | |||
Additional construction capital costs, threshold | $ 800 | ||
Category II | Maximum | |||
Public Utilities, General Disclosures [Line Items] | |||
Additional construction capital costs, threshold | $ 1,600 | ||
Category III | |||
Public Utilities, General Disclosures [Line Items] | |||
Percentage of construction costs responsible to pay | 65.70% | ||
Additional construction capital costs | $ 100 | ||
Category III | Vogtle Owners | |||
Public Utilities, General Disclosures [Line Items] | |||
Percentage of construction costs responsible to pay | 34.30% | ||
Category III | Maximum | |||
Public Utilities, General Disclosures [Line Items] | |||
Additional construction capital costs, threshold | $ 2,100 |
REGULATORY MATTERS - GPC Nucl_2
REGULATORY MATTERS - GPC Nuclear Construction Regulatory Matters (Details) - Georgia Power $ in Millions | Feb. 18, 2021USD ($) | Jan. 01, 2021 | Nov. 03, 2020USD ($) | Jan. 01, 2020 | Jan. 11, 2018USD ($) | Jan. 01, 2018 | Jan. 01, 2016 | Jun. 30, 2020USD ($)report | Dec. 31, 2022USD ($) | Dec. 31, 2021USD ($) | Dec. 31, 2020USD ($) | Dec. 31, 2019USD ($) | Dec. 31, 2018USD ($) | Dec. 31, 2015USD ($) | Dec. 31, 2009USD ($) | Sep. 17, 2019 | Dec. 31, 2013 |
Public Utilities, General Disclosures [Line Items] | |||||||||||||||||
Retail rate of return on common equity | 10.50% | 10.95% | |||||||||||||||
Plant Vogtle Units 3 And 4 | |||||||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||||||
Estimated in-service capital cost | $ 4,418 | ||||||||||||||||
Proceeds from recovery of financing costs | $ 2,500 | ||||||||||||||||
Project capital cost forecast | $ 7,300 | ||||||||||||||||
Requested decrease in NCCR tariff | $ 142 | ||||||||||||||||
Additional construction capital costs | $ 3,300 | ||||||||||||||||
Payments for contractor settlement agreement | 300 | ||||||||||||||||
Amendment to estimated in-service capital cost | $ 5,680 | ||||||||||||||||
Retail rate of return on common equity | 10.95% | ||||||||||||||||
Authorized ROE | 8.30% | 10.00% | 10.00% | ||||||||||||||
Potential decrease each month, percentage | 0.10% | ||||||||||||||||
Return on equity reduction, negative impact on earnings | $ 150 | $ 75 | $ 100 | ||||||||||||||
Plant Vogtle Units 3 And 4 | Subsequent Event | |||||||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||||||
Approval of construction capital costs | $ 670 | ||||||||||||||||
Plant Vogtle Units 3 And 4 | Twenty Third Vogtle Construction Monitoring Report | |||||||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||||||
Number of approved construction monitoring reports | report | 23 | ||||||||||||||||
Approval of construction capital costs | $ 8,100 | ||||||||||||||||
Maximum guarantee | 1,700 | ||||||||||||||||
Customer refund | $ 188 | ||||||||||||||||
Plant Vogtle Units 3 And 4 | Scenario, Forecast | |||||||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||||||
Authorized ROE | 5.30% | ||||||||||||||||
Return on equity reduction, negative impact on earnings | $ 200 | $ 260 |
REGULATORY MATTERS - MPC 2019 B
REGULATORY MATTERS - MPC 2019 Base Rate Case and Performance Evaluation Plan (Details) $ in Millions | Jun. 25, 2020USD ($) | Mar. 17, 2020USD ($) | Dec. 31, 2020USD ($)filing | Dec. 31, 2018USD ($) | Dec. 31, 2019USD ($) |
Public Utilities, General Disclosures [Line Items] | |||||
Net regulatory assets | $ 5,493 | $ 3,838 | |||
Mississippi Power | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Public utilities, approved rate increase (decrease), amount | $ (16.7) | $ 21.6 | |||
Approved rate decrease, percent | 1.85% | ||||
Base rate case filing, measurement input, average equity ratio | 53.00% | ||||
Base rate case filing, measurement input, maximum equity ratio | 55.00% | ||||
Base rate case filing, measurement input, return on investment | 7.57% | ||||
Regulatory asset amortization period | 4 years | ||||
Regulatory liability amortization period | 3 years | ||||
Annual base rate adjustment, increase in depreciation | $ 10 | ||||
Annual base rate adjustment, compensation costs excluded | $ 3.9 | ||||
Performance evaluation plan, number of filings per calendar year | filing | 2 | ||||
Requested rate increase, amount | $ 2 | $ 26 | |||
Authorized ROE | 9.33% | ||||
Regulatory equity ratio | 50.00% | ||||
Amount approved for recovery | $ 2 | ||||
Net regulatory assets | $ 136 | 64 | |||
Retail rate of return on common equity | 9.31% | ||||
Mississippi Power | Deferred Income Tax Charges | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Regulatory liabilities | $ 44 | ||||
Mississippi Power | Contested Compensation Costs | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Regulatory asset amortization period | 4 years | ||||
Net regulatory assets | $ 4 | $ 4 | |||
Mississippi Power | Weighted Average | Measurement Input, Average Customer Price | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Performance evaluation plan, measurement input | 0.40 | ||||
Mississippi Power | Weighted Average | Measurement Input, Service Reliability | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Performance evaluation plan, measurement input | 0.40 | ||||
Mississippi Power | Weighted Average | Measurement Input, Customer Satisfaction | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Performance evaluation plan, measurement input | 0.20 | ||||
Mississippi Power | Maximum | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Regulatory asset amortization period | 8 years | ||||
Allowed equity ratio | 51.00% |
REGULATORY MATTERS - MPC Reserv
REGULATORY MATTERS - MPC Reserve Margin and Environmental Compliance Overview Plans (Details) $ in Millions | Feb. 12, 2021USD ($) | Jun. 25, 2020USD ($) | Mar. 17, 2020 | Dec. 31, 2019 | Dec. 31, 2018USD ($) | Dec. 17, 2020MW | Oct. 31, 2019USD ($) |
Mississippi Power | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Required fossil-stream generation retirements (in MWs) | MW | 950 | ||||||
Requested rate increase, amount | $ 2 | $ 26 | |||||
Approved rate increase, percent | (1.85%) | ||||||
Mississippi Power | Subsequent Event | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Requested rate increase, amount | $ 28 | ||||||
Mississippi Power | Environmental Compliance Overview Plan | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Requested rate increase, amount | $ 17 | ||||||
Percent ownership | 50.00% | ||||||
Public utilities, requested cost to complete environmental compliance projects | $ 66 | ||||||
Mississippi Power | Environmental Compliance Overview Plan | Subsequent Event | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Requested rate increase, amount | $ 9 | ||||||
Mississippi Power | Maximum | Environmental Compliance Overview Plan | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Approved rate increase, percent | 2.00% | ||||||
Mississippi Power And Gulf Power | Environmental Compliance Overview Plan | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Public utilities, requested cost to complete environmental compliance projects | 125 | ||||||
Plant Watson Unit 4 | Mississippi Power | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Alternative accelerated retirement period | 2 years | ||||||
Plant Watson Unit 5 | Mississippi Power | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Alternative accelerated retirement period | 7 years | ||||||
Plant Greene County Units 1 And 2 | Mississippi Power | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Alternative accelerated retirement period | 4 years | 4 years | |||||
Ash Pond | Mississippi Power | Environmental Compliance Overview Plan | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Public utilities, requested cost to complete environmental compliance projects | $ 17 |
REGULATORY MATTERS - MPC Fuel C
REGULATORY MATTERS - MPC Fuel Cost Recovery and Ad Valorem Tax Adjustment (Details) - Mississippi Power - USD ($) $ in Millions | Feb. 12, 2021 | Jun. 25, 2020 | Mar. 17, 2020 | Feb. 28, 2021 | Jan. 31, 2021 | Feb. 29, 2020 | Jan. 31, 2020 | Feb. 28, 2019 | Jan. 31, 2019 | Feb. 28, 2018 | Dec. 31, 2018 | Dec. 31, 2020 | Dec. 31, 2019 |
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Public utilities, approved rate increase (decrease), amount | $ (16.7) | $ 21.6 | |||||||||||
PSC retail increase | 7 | $ 10 | $ 2 | ||||||||||
Requested rate increase, amount | $ 2 | $ 26 | |||||||||||
Subsequent Event | |||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Requested rate increase, amount | $ 28 | ||||||||||||
Retail electric revenues | |||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Public utilities, approved rate increase (decrease), amount | $ (24) | $ (35) | $ 39 | ||||||||||
Over recovered fuel cost | 24 | 23 | |||||||||||
Retail electric revenues | Scenario, Forecast | |||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Public utilities, approved rate increase (decrease), amount | $ 2 | ||||||||||||
MRA Revenue | |||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Public utilities, approved rate increase (decrease), amount | $ 1 | $ 16 | |||||||||||
Over recovered fuel cost | $ 10 | $ 6 | |||||||||||
MRA Revenue | Subsequent Event | |||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Public utilities, approved rate increase (decrease), amount | $ 5 |
REGULATORY MATTERS - MPC System
REGULATORY MATTERS - MPC System Restoration Rider (Details) - USD ($) | 12 Months Ended | |||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Oct. 28, 2020 | |
Major storms | ||||
Public Utilities, General Disclosures [Line Items] | ||||
Storm damage reserves | $ 326,000,000 | $ 170,000,000 | $ 74,000,000 | |
Mississippi Power | ||||
Public Utilities, General Disclosures [Line Items] | ||||
Threshold above which actual damages are charged to the reserve (individually exceed) | $ 50,000 | |||
SRR rate | 0.00% | 0.00% | 0.00% | |
Mississippi Power | Retail electric revenues | ||||
Public Utilities, General Disclosures [Line Items] | ||||
Property damage reserve | $ 4,000,000 | |||
Mississippi Power | Major storms | ||||
Public Utilities, General Disclosures [Line Items] | ||||
Storm damage reserves | $ 1,000,000 | $ 1,000,000 | $ 1,000,000 | |
Mississippi Power | Hurricane Zeta | ||||
Public Utilities, General Disclosures [Line Items] | ||||
Property damage reserve | $ 43,000,000 | |||
Mississippi Power | Mississippi Public Service Commission | ||||
Public Utilities, General Disclosures [Line Items] | ||||
Period to agree on system restoration rider | 3 years |
REGULATORY MATTERS - MPC Deferr
REGULATORY MATTERS - MPC Deferral of Incremental COVID-19 Costs and Municipal and Rural Associations Tariff (Details) $ in Millions | Apr. 01, 2021 | Feb. 12, 2021USD ($) | Jun. 25, 2020USD ($) | Jan. 01, 2019USD ($) | Dec. 31, 2020USD ($) | Dec. 31, 2018USD ($) | Apr. 01, 2018MW | Mar. 31, 2018MW |
Mississippi Power | ||||||||
Public Utilities, General Disclosures [Line Items] | ||||||||
Incremental COVID-19 costs deferred | $ 1 | |||||||
Requested rate increase, amount | $ 2 | $ 26 | ||||||
Mississippi Power | Subsequent Event | ||||||||
Public Utilities, General Disclosures [Line Items] | ||||||||
Requested rate increase, amount | $ 28 | |||||||
Mississippi Power | MRA Revenue | ||||||||
Public Utilities, General Disclosures [Line Items] | ||||||||
Decrease in base rate under cost based electric tariff due to settlement | $ 3.7 | |||||||
Mississippi Power | Cooperative Energy | ||||||||
Public Utilities, General Disclosures [Line Items] | ||||||||
Period of notice to cancel counterparty | 10 years | |||||||
Counterparty's option to decrease services, percentage | 2.50% | |||||||
Counterparty's option to reduce services, maximum percentage | 11.00% | |||||||
Counterparty's option to reduce services, maximum | $ 9 | |||||||
Approximate nameplate capacity (in MW) | MW | 286 | 86 | ||||||
Cooperative Energy | Southern Company Services, Inc. | ||||||||
Public Utilities, General Disclosures [Line Items] | ||||||||
Network integration transmission service agreement, term of agreement | 10 years | |||||||
Cooperative Energy | Southern Company Services, Inc. | Subsequent Event | Scenario, Forecast | ||||||||
Public Utilities, General Disclosures [Line Items] | ||||||||
Network integration transmission service agreement, renewal term | 10 years |
REGULATORY MATTERS - GAS Schedu
REGULATORY MATTERS - GAS Schedule of Utility Regulation and Rate Design (Details) | 1 Months Ended | 12 Months Ended | |||
Dec. 31, 2019 | Oct. 31, 2019 | Jan. 31, 2018 | Dec. 31, 2020 | Dec. 31, 2017 | |
Nicor Gas | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Authorized ROE | 9.73% | 9.80% | 9.73% | ||
Atlanta Gas Light | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Authorized ROE | 10.25% | 10.25% | |||
Virginia Natural Gas | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Authorized ROE | 9.50% | 9.50% | |||
Chattanooga Gas | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Authorized ROE | 9.80% |
REGULATORY MATTERS - GAS Infras
REGULATORY MATTERS - GAS Infrastructure Replacement Programs and Capital Projects (Details) $ in Millions | 12 Months Ended | 21 Months Ended | |||||
Dec. 31, 2020USD ($) | Dec. 31, 2019USD ($)mi | Dec. 31, 2018USD ($) | Dec. 31, 2014 | Dec. 31, 2013 | Sep. 30, 2019USD ($) | Dec. 15, 2020mi | |
Public Utilities, General Disclosures [Line Items] | |||||||
Capital expenditures related to qualifying projects | $ 7,441 | $ 7,555 | $ 8,001 | ||||
Southern Company Gas | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Capital expenditures related to qualifying projects | 1,471 | 1,408 | 1,388 | ||||
Nicor Gas | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Public utilities, approved rate increase, recovery of investment amount | $ 65 | ||||||
Capital expenditures related to qualifying projects | $ 396 | $ 409 | |||||
Nicor Gas | Regulatory Infrastructure Program | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Program duration period | 9 years | ||||||
Nicor Gas | Maximum | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Infrastructure investment, annual customer rate increase | 4.00% | ||||||
Infrastructure investment, annual customer rate increase in any given year | 5.50% | ||||||
Virginia Natural Gas | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Header improvement project, scope of project (in miles) | mi | 24.1 | 9.5 | |||||
Virginia Natural Gas | SAVE | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Program duration period | 6 years | ||||||
Approved infrastructure replacement program, approved investment amount, current fiscal year | 365 | ||||||
Infrastructure replacement program, approved investment variance amount | 5 | ||||||
Virginia Natural Gas | SAVE | Year 2018 | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Approved infrastructure replacement program, approved investment amount, current fiscal year | 35 | ||||||
Virginia Natural Gas | SAVE | Year 2019 | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Approved infrastructure replacement program, approved investment amount, current fiscal year | 40 | ||||||
Virginia Natural Gas | SAVE | Year 2020 | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Approved infrastructure replacement program, approved investment amount, current fiscal year | 50 | ||||||
Virginia Natural Gas | SAVE | Year 2021 | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Approved infrastructure replacement program, approved investment amount, current fiscal year | 60 | ||||||
Virginia Natural Gas | SAVE | Year 2022 | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Approved infrastructure replacement program, approved investment amount, current fiscal year | 70 | ||||||
Virginia Natural Gas | SAVE | Year 2023 | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Approved infrastructure replacement program, approved investment amount, current fiscal year | 70 | ||||||
Virginia Natural Gas | SAVE | Year 2024 | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Approved infrastructure replacement program, approved investment amount, current fiscal year | 70 | ||||||
Atlanta Gas Light | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Annual proceeds from strategic economic development projects | 15 | ||||||
Atlanta Gas Light | True Up Recovery | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Gain contingency, unrecorded amount | 113 | ||||||
Atlanta Gas Light | True-Up Recovery, Unrecognized Equity | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Gain contingency, unrecorded amount | 59 | ||||||
Operating Segments | Gas distribution operations | Southern Company Gas | |||||||
Public Utilities, General Disclosures [Line Items] | |||||||
Gross property additions | $ 1,500 |
REGULATORY MATTERS - GAS Sche_2
REGULATORY MATTERS - GAS Schedule of Infrastructure Replacement Programs and Capital Projects (Details) - Southern Company Gas $ in Millions | 12 Months Ended |
Dec. 31, 2020USD ($)mi | |
Public Utilities, General Disclosures [Line Items] | |
Expenditures in 2020 | $ | $ 438 |
Expenditures Since Project Inception | $ | $ 2,394 |
Pipe Installed Since Project Inception (in miles) | mi | 1,409 |
Scope of Program (in miles) | mi | 2,220 |
Investing In Illinois | |
Public Utilities, General Disclosures [Line Items] | |
Expenditures in 2020 | $ | $ 389 |
Expenditures Since Project Inception | $ | $ 2,101 |
Pipe Installed Since Project Inception (in miles) | mi | 996 |
Scope of Program (in miles) | mi | 1,450 |
Program Duration | 9 years |
SAVE | |
Public Utilities, General Disclosures [Line Items] | |
Expenditures in 2020 | $ | $ 49 |
Expenditures Since Project Inception | $ | $ 293 |
Pipe Installed Since Project Inception (in miles) | mi | 413 |
Scope of Program (in miles) | mi | 770 |
Program Duration | 13 years |
REGULATORY MATTERS - GAS Natura
REGULATORY MATTERS - GAS Natural Gas Cost Recovery (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Southern Company Gas | ||
Public Utilities, General Disclosures [Line Items] | ||
Over recovered fuel cost | $ 88 | $ 74 |
REGULATORY MATTERS - GAS Rate P
REGULATORY MATTERS - GAS Rate Proceedings and Infrastructure Replacement Programs and Capital Projects (Details) - USD ($) $ in Millions | Feb. 16, 2021 | Jan. 14, 2021 | Jul. 01, 2020 | Jun. 01, 2020 | May 05, 2018 | Dec. 31, 2019 | Oct. 31, 2019 | Jan. 31, 2018 | Dec. 31, 2020 | Dec. 31, 2018 | Dec. 31, 2017 | Oct. 31, 2018 | Jul. 31, 2018 |
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Net regulatory assets | $ 3,838 | $ 5,493 | |||||||||||
Nicor Gas | |||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Public utilities, approved rate increase (decrease), amount | $ (44) | $ 168 | $ 137 | ||||||||||
Authorized ROE | 9.73% | 9.80% | 9.73% | ||||||||||
Public utilities, approved equity capital structure, percentage | 54.20% | ||||||||||||
Nicor Gas | COVID-19 | |||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Net regulatory assets | $ 9 | ||||||||||||
Nicor Gas | Subsequent Event | |||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Requested rate increase, amount | $ 293 | ||||||||||||
Requested rate increase, amount, recovery of investments | $ 94 | ||||||||||||
Requested ROE | 10.35% | ||||||||||||
Requested equity ratio | 54.50% | ||||||||||||
Nicor Gas | Investing In Illinois | |||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Public utilities, approved rate increase amount recovery of investments | $ 65 | $ 93 | |||||||||||
Atlanta Gas Light | |||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Public utilities, approved rate increase (decrease), amount | $ 65 | $ (16) | |||||||||||
Authorized ROE | 10.25% | 10.25% | |||||||||||
Public utilities, approved equity capital structure, percentage | 56.00% | ||||||||||||
Requested rate increase, amount | $ 37.6 | ||||||||||||
Requested rate increase, projected test year, term | 12 months | ||||||||||||
Contract with customer, liability, bill credits | $ 8 | $ 8 | |||||||||||
Approved rate increase, percent | 4.00% | ||||||||||||
Regulatory equity ratio | 55.00% | ||||||||||||
Public utilities, maximum base rate percentage | 5.00% | 5.00% | |||||||||||
Atlanta Gas Light | Subsequent Event | |||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Integrated capacity delivery plan, interstate and intrastate capacity asset requirements, term | 10 years | ||||||||||||
Integrated capacity delivery plan, interstate and intrastate capacity asset requirements, detailed plan term | 3 years | ||||||||||||
Integrated capacity delivery plan, capital budgets and related operations and maintenance spending, term | 10 years | ||||||||||||
Atlanta Gas Light | Minimum | |||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Authorized ROE | 10.05% | 10.55% | |||||||||||
Atlanta Gas Light | Maximum | |||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Authorized ROE | 10.45% | 10.95% | |||||||||||
Virginia Natural Gas | |||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Public utilities, approved rate increase (decrease), amount | $ (14) | ||||||||||||
Authorized ROE | 9.50% | 9.50% | |||||||||||
Requested rate increase, amount | $ 49.6 | ||||||||||||
Requested rate increase, projected test year, term | 12 months | ||||||||||||
Requested ROE | 10.35% | ||||||||||||
Requested equity ratio | 54.00% | ||||||||||||
Contract with customer, liability, bill credits | $ 14 | ||||||||||||
Virginia Natural Gas | Minimum | |||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Authorized ROE | 9.00% | ||||||||||||
Virginia Natural Gas | Maximum | |||||||||||||
Public Utilities, General Disclosures [Line Items] | |||||||||||||
Authorized ROE | 10.00% |
REGULATORY MATTERS - GAS Sche_3
REGULATORY MATTERS - GAS Schedule of Unrecognized Ratemaking Amounts (Details) - Regulatory Asset Off Balance Sheet - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Atlanta Gas Light | ||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||
Regulatory asset | $ 59 | $ 70 |
Virginia Natural Gas | ||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||
Regulatory asset | 10 | 10 |
Nicor Gas | ||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||
Regulatory asset | 3 | 2 |
Southern Company Gas | ||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||
Regulatory asset | $ 72 | $ 82 |
CONTINGENCIES, COMMITMENTS, A_3
CONTINGENCIES, COMMITMENTS, AND GUARANTEES - SO Litigation (Details) - Shareholder Derivative Lawsuits - Pending Litigation - lawsuit | 12 Months Ended | |
Dec. 31, 2018 | Dec. 31, 2017 | |
Loss Contingencies [Line Items] | ||
Number of claims | 2 | |
Stay period | 30 days |
CONTINGENCIES, COMMITMENTS, A_4
CONTINGENCIES, COMMITMENTS, AND GUARANTEES - MPC Litigation (Details) $ in Millions | 1 Months Ended | 12 Months Ended |
Mar. 31, 2019plaintiff | Dec. 31, 2018USD ($)plaintiffdefendant | |
Schedule of Regulatory Assets and Liabilities [Line Items] | ||
Number of plaintiffs | 10 | |
Purported Violations Of Mississippi Consumer Protection Act | Pending Litigation | Mississippi Power | ||
Schedule of Regulatory Assets and Liabilities [Line Items] | ||
Number of plaintiffs | 4 | |
Loss contingency, number of defendants | defendant | 3 | |
Public utilities, underpayment of refunds | $ | $ 23.5 |
CONTINGENCIES, COMMITMENTS, A_5
CONTINGENCIES, COMMITMENTS, AND GUARANTEES - Environmental Remediation (Details) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020USD ($)sitestate | Dec. 31, 2019USD ($) | Dec. 31, 2018USD ($) | |
Accrual for Environmental Loss Contingencies, Balance Sheet Classification [Abstract] | |||
Accrued environmental remediation | $ 216 | $ 234 | |
Georgia Power | |||
Environmental Exit Cost [Line Items] | |||
Costs recovered annually | 12 | 2 | $ 2 |
Accrual for Environmental Loss Contingencies, Balance Sheet Classification [Abstract] | |||
Environmental remediation liability, current | 15 | 15 | |
Accrued environmental remediation | 0 | 0 | |
Under recovered environmental remediation costs, other regulatory assets, current | 12 | 12 | |
Under recovered environmental remediation costs, other regulatory assets, deferred | 29 | 40 | |
Southern Company | |||
Accrual for Environmental Loss Contingencies, Balance Sheet Classification [Abstract] | |||
Environmental remediation liability, current | 44 | 51 | |
Accrued environmental remediation | 216 | 234 | |
Under recovered environmental remediation costs, other regulatory assets, current | 46 | 49 | |
Under recovered environmental remediation costs, other regulatory assets, deferred | 265 | 300 | |
Southern Company Gas | |||
Accrual for Environmental Loss Contingencies, Balance Sheet Classification [Abstract] | |||
Environmental remediation liability, current | 29 | 36 | |
Accrued environmental remediation | 216 | 233 | |
Under recovered environmental remediation costs, other regulatory assets, current | 34 | 37 | |
Under recovered environmental remediation costs, other regulatory assets, deferred | $ 236 | $ 260 | |
Southern Company Gas | Manufactured Gas Plants | |||
Environmental Exit Cost [Line Items] | |||
Number of sites | site | 40 | ||
Number of states in which subject to environmental remediation liabilities | state | 4 |
CONTINGENCIES, COMMITMENTS, A_6
CONTINGENCIES, COMMITMENTS, AND GUARANTEES - Nuclear Fuel Disposal Costs and Nuclear Insurance (Details) | 12 Months Ended | 108 Months Ended |
Dec. 31, 2020USD ($)plant | Dec. 31, 2019USD ($) | |
Jointly Owned Utility Plant Interests [Line Items] | ||
Maximum fund for public liability claims arising from a single nuclear incident under price - anderson amendments act | $ 13,800,000,000 | |
Maximum insurance coverage provided by American Nuclear Insurers to each nuclear plant | 450,000,000 | |
Maximum amount that a company could be assessed per incident for each licensed reactor | 138,000,000 | |
Maximum aggregate amount that a reactor can assess in a calendar period for each incident | $ 20,000,000 | |
Block period considered for inflation adjustment against maximum assessment per reactor | 5 years | |
Maximum deductible waiting period | 182 days | |
Maximum coverage per occurrence per unit limit to obtain replacement power | $ 490,000,000 | |
Aggregate payment for claims resulting from terrorist acts in one year period | 3,200,000,000 | |
Vogtle Units 3 and 4 | ||
Jointly Owned Utility Plant Interests [Line Items] | ||
Maximum limits for accidental property damage occurring during construction | $ 2,750,000,000 | |
Alabama Power and Georgia Power | ||
Jointly Owned Utility Plant Interests [Line Items] | ||
Number of nuclear fuel plants | plant | 3 | |
Maximum property damage insurance provided to nuclear generating facilities | $ 1,500,000,000 | |
Maximum additional coverage provided for losses under excess insurance | 1,250,000,000 | |
Maximum additional coverage provided for losses under excess insurance, non-nuclear losses | $ 750,000,000 | |
Elected deductible waiting period | 84 days | |
Alabama Power | ||
Jointly Owned Utility Plant Interests [Line Items] | ||
Maximum assessment, excluding any applicable state premium taxes | $ 275,000,000 | |
Maximum aggregate amount to be paid in one year | 41,000,000 | |
Current maximum annual assessments under NEIL policies | 56,000,000 | |
Alabama Power | Positive Outcome of Litigation | ||
Jointly Owned Utility Plant Interests [Line Items] | ||
Outstanding claims | $ 110,000,000 | |
Georgia Power | ||
Jointly Owned Utility Plant Interests [Line Items] | ||
Maximum assessment, excluding any applicable state premium taxes | 267,000,000 | |
Maximum aggregate amount to be paid in one year | 40,000,000 | |
Current maximum annual assessments under NEIL policies | $ 84,000,000 | |
Georgia Power | Positive Outcome of Litigation | ||
Jointly Owned Utility Plant Interests [Line Items] | ||
Outstanding claims | $ 132,000,000 |
CONTINGENCIES, COMMITMENTS, A_7
CONTINGENCIES, COMMITMENTS, AND GUARANTEES - SO Other Matters (Details) $ in Millions | 3 Months Ended | 12 Months Ended | ||||
Dec. 31, 2020USD ($)leveraged_leaseassetnetworkheating_system | Jun. 30, 2020USD ($) | Dec. 31, 2019USD ($)leveraged_lease | Dec. 31, 2020USD ($)leveraged_leaseassetnetworkheating_system | Dec. 31, 2019USD ($)leveraged_lease | Dec. 31, 2018USD ($) | |
Commitments and Contingencies Disclosure [Abstract] | ||||||
Number of leveraged leases | 4 | 4 | 4 | 4 | ||
Number of domestic leveraged leases | 2 | 2 | 2 | 2 | ||
Number of international leveraged leases | 2 | 2 | 2 | 2 | ||
Lease, impairment loss | $ | $ 52 | $ 154 | $ 17 | $ 206 | $ 0 | $ 0 |
Lease, impairment loss, after tax | $ | $ 31 | $ 74 | $ 13 | |||
Leveraged leases, number of gas distribution networks | network | 9 | 9 | ||||
Leveraged leases, number of district heating systems | heating_system | 2 | 2 | ||||
Leveraged leases, number of assets remaining | asset | 10 | 10 | ||||
Leveraged leases, purchase option, notice period | 1 year |
CONTINGENCIES, COMMITMENTS, A_8
CONTINGENCIES, COMMITMENTS, AND GUARANTEES - MPC Other Matters (Details) | Dec. 31, 2019 | Jan. 01, 2019USD ($) | Dec. 31, 2020USD ($)MW | Dec. 31, 2019USD ($) | Dec. 31, 2018USD ($) | Dec. 31, 2025USD ($) | Jan. 15, 2024USD ($) | Dec. 31, 2016USD ($) | Dec. 31, 2010USD ($) |
Loss Contingencies [Line Items] | |||||||||
Period costs | $ 19,000,000 | $ 37,000,000 | |||||||
Mississippi Power | |||||||||
Loss Contingencies [Line Items] | |||||||||
Plant capacity under coal gasification combined cycle technology | MW | 582 | ||||||||
Period costs | $ 0 | 1,000,000 | |||||||
Kemper County energy facility assets, net | Mississippi Power | |||||||||
Loss Contingencies [Line Items] | |||||||||
Reduction in customer rates annually | $ 26,800,000 | ||||||||
Pre-tax charge to income | 4,000,000 | $ 24,000,000 | 37,000,000 | ||||||
After tax charge to income | $ 3,000,000 | 68,000,000 | |||||||
Firm transportation agreement, term | 15 years | ||||||||
Government grants expected | $ 137,000,000 | $ 270,000,000 | |||||||
Government grants received | $ 387,000,000 | ||||||||
Scenario, Forecast | Kemper County energy facility assets, net | Mississippi Power | Minimum | |||||||||
Loss Contingencies [Line Items] | |||||||||
Period costs | $ 10,000,000 | ||||||||
Scenario, Forecast | Kemper County energy facility assets, net | Mississippi Power | Maximum | |||||||||
Loss Contingencies [Line Items] | |||||||||
Period costs | $ 20,000,000 | ||||||||
Scenario, Forecast | Plant Daniel | Mississippi Power | |||||||||
Loss Contingencies [Line Items] | |||||||||
Payments to acquire businesses | $ 1 | ||||||||
Business combination, option to purchase, period | 120 days | ||||||||
Scenario, Forecast | Plant Daniel | Gulf Power | |||||||||
Loss Contingencies [Line Items] | |||||||||
Undivided ownership interest to be restructured | 50.00% | ||||||||
Percent ownership in individual unit | 100.00% | ||||||||
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Gulf Power | |||||||||
Loss Contingencies [Line Items] | |||||||||
Proceeds from divestiture of businesses, amount held back | $ 75,000,000 |
CONTINGENCIES, COMMITMENTS, A_9
CONTINGENCIES, COMMITMENTS, AND GUARANTEES - GAS Other Matters (Details) | Feb. 20, 2020 | Dec. 31, 2020USD ($) | Dec. 31, 2019USD ($) | Dec. 31, 2018USD ($) | Jan. 30, 2020phasemi | Dec. 31, 2015miBcf |
Loss Contingencies [Line Items] | ||||||
Equity investments in unconsolidated subsidiaries | $ 1,362,000,000 | $ 1,303,000,000 | ||||
Impairment charges | 0 | 168,000,000 | $ 210,000,000 | |||
Southern Company Gas | ||||||
Loss Contingencies [Line Items] | ||||||
Equity investments in unconsolidated subsidiaries | 1,290,000,000 | 1,251,000,000 | ||||
Impairment of long-lived assets | 0 | |||||
Impairment charges | 0 | 115,000,000 | $ 42,000,000 | |||
Southern Company Gas | PennEast Pipeline | ||||||
Loss Contingencies [Line Items] | ||||||
Ownership percentage, equity method investment | 20.00% | |||||
Pipeline infrastructure | mi | 118 | |||||
Equity investments in unconsolidated subsidiaries | $ 91,000,000 | 82,000,000 | ||||
Southern Company Gas | SNG | ||||||
Loss Contingencies [Line Items] | ||||||
Ownership percentage, equity method investment | 50.00% | |||||
Equity investments in unconsolidated subsidiaries | $ 1,167,000,000 | 1,137,000,000 | ||||
PennEast Pipeline | ||||||
Loss Contingencies [Line Items] | ||||||
Extension request, term | 2 years | |||||
Construction amendment, number of phases | phase | 2 | |||||
Construction amendment, number of miles of pipe, phase one | mi | 68 | |||||
Minimum | Southern Company Gas | PennEast Pipeline | ||||||
Loss Contingencies [Line Items] | ||||||
Natural gas pipeline capacity (volume) | Bcf | 1 | |||||
Maximum | PennEast Pipeline | Southern Company Gas | ||||||
Loss Contingencies [Line Items] | ||||||
Construction contingency estimate | $ 300,000,000 | |||||
Natural Gas Storage Facility | Southern Company Gas | ||||||
Loss Contingencies [Line Items] | ||||||
Impairment charges | 91,000,000 | |||||
Impairment charges, after tax | $ 69,000,000 |
CONTINGENCIES, COMMITMENTS, _10
CONTINGENCIES, COMMITMENTS, AND GUARANTEES - Commitments (Details) - Georgia Power - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
MEAG Power | |||
Loss Contingencies [Line Items] | |||
Percent ownership | 5.00% | ||
Plant Vogtle Units 1 and 2 | |||
Loss Contingencies [Line Items] | |||
Capacity payments | $ 5 | $ 6 | $ 8 |
Recorded Unconditional Purchase Obligation, Fiscal Year Maturity Schedule [Abstract] | |||
Recorded unconditional purchase obligation | 49 | ||
2021 | 5 | ||
2022 | 4 | ||
2023 | 3 | ||
2024 | 3 | ||
2025 | 3 | ||
2026 and thereafter | $ 31 |
CONTINGENCIES, COMMITMENTS, _11
CONTINGENCIES, COMMITMENTS, AND GUARANTEES - GAS Commitments (Details) MMBTU in Millions, $ in Millions | 12 Months Ended |
Dec. 31, 2020USD ($)MMBTU | |
Pipeline Charges, Storage Capacity, and Gas Supply | |
Debt maturing in June 2021 | $ 3,506 |
Southern Company Gas | |
Long-term Purchase Commitment [Line Items] | |
Natural gas pipeline capacity | MMBTU | 31 |
Long-term purchase commitment amount | $ 72 |
Pipeline Charges, Storage Capacity, and Gas Supply | |
Debt maturing in June 2021 | $ 330 |
Southern Company Gas | SNG | |
Pipeline Charges, Storage Capacity, and Gas Supply | |
Ownership percentage, equity method investment | 50.00% |
Commitment to fund contingent capital contribution | $ 150 |
SNG | |
Pipeline Charges, Storage Capacity, and Gas Supply | |
Debt maturing in June 2021 | 300 |
Pipeline Charges, Storage Capacity, and Gas Supply | Southern Company Gas | |
Pipeline Charges, Storage Capacity, and Gas Supply | |
2021 | 719 |
2022 | 529 |
2023 | 441 |
2024 | 311 |
2025 | 285 |
Thereafter | 1,035 |
Total | $ 3,320 |
CONTINGENCIES, COMMITMENTS, _12
CONTINGENCIES, COMMITMENTS, AND GUARANTEES - Guarantees (Details) - USD ($) $ in Millions | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Recorded Unconditional Purchase Obligation [Line Items] | ||
Short-term debt | $ 609 | $ 2,055 |
Alabama Power | ||
Recorded Unconditional Purchase Obligation [Line Items] | ||
Jointly owned affiliate equity | 85 | |
Jointly owned affiliate long term debt | 100 | |
SEGCO | Alabama Power | ||
Recorded Unconditional Purchase Obligation [Line Items] | ||
Short-term debt | 25 | |
SEGCO | Maturity December 1, 2018 | Alabama Power | ||
Recorded Unconditional Purchase Obligation [Line Items] | ||
Guarantee of unsecured senior notes | $ 100 |
REVENUE FROM CONTRACTS WITH C_3
REVENUE FROM CONTRACTS WITH CUSTOMERS - Disaggregate Revenue Sources (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | $ 21,097 | $ 22,596 | $ 25,241 |
Total operating revenues | 20,375 | 21,419 | 23,495 |
Retail electric revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 13,677 | 14,445 | 15,087 |
Residential | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 6,113 | 6,164 | 6,586 |
Commercial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 4,699 | 5,065 | 5,255 |
Industrial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 2,775 | 3,126 | 3,152 |
Other | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 90 | 90 | 94 |
Natural gas distribution revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 2,888 | 2,989 | 3,175 |
Residential | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 1,338 | 1,413 | 1,525 |
Commercial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 340 | 389 | 436 |
Transportation | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 971 | 907 | 944 |
Industrial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 30 | 35 | 40 |
Other | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 209 | 245 | 230 |
Wholesale electric revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 1,399 | 1,518 | 1,711 |
PPA energy revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 735 | 833 | 950 |
PPA capacity revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 454 | 453 | 498 |
Non-PPA revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 210 | 232 | 263 |
Other natural gas revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 2,151 | 2,609 | 3,739 |
Gas pipeline investments | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 32 | 32 | |
Wholesale gas services | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 1,727 | 2,095 | 3,083 |
Gas marketing services | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 391 | 440 | 571 |
Other natural gas revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 33 | 42 | 53 |
Other revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 982 | 1,035 | 1,529 |
Other revenue sources | |||
Disaggregation of Revenue [Line Items] | |||
Other | 3,764 | 4,266 | 5,108 |
Other adjustments | |||
Disaggregation of Revenue [Line Items] | |||
Other | (4,486) | (5,443) | (6,854) |
Alabama Power | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 5,646 | 6,152 | 5,803 |
Total operating revenues | 5,830 | 6,125 | 6,032 |
Alabama Power | Retail electric revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 5,203 | 5,671 | 5,215 |
Alabama Power | Residential | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 2,377 | 2,509 | 2,285 |
Alabama Power | Commercial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 1,512 | 1,677 | 1,541 |
Alabama Power | Industrial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 1,293 | 1,460 | 1,364 |
Alabama Power | Other | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 21 | 25 | 25 |
Alabama Power | Natural gas distribution revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Alabama Power | Residential | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Alabama Power | Commercial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Alabama Power | Transportation | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Alabama Power | Industrial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Alabama Power | Other | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Alabama Power | Wholesale electric revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 284 | 328 | 378 |
Alabama Power | PPA energy revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 133 | 145 | 158 |
Alabama Power | PPA capacity revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 108 | 102 | 101 |
Alabama Power | Non-PPA revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 43 | 81 | 119 |
Alabama Power | Other natural gas revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Alabama Power | Gas pipeline investments | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | |
Alabama Power | Wholesale gas services | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Alabama Power | Gas marketing services | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Alabama Power | Other natural gas revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Alabama Power | Other revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 159 | 153 | 210 |
Alabama Power | Other revenue sources | |||
Disaggregation of Revenue [Line Items] | |||
Other | 184 | (27) | 229 |
Alabama Power | Other adjustments | |||
Disaggregation of Revenue [Line Items] | |||
Other | 0 | 0 | 0 |
Georgia Power | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 8,215 | 8,418 | 8,091 |
Total operating revenues | 8,309 | 8,408 | 8,420 |
Georgia Power | Retail electric revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 7,666 | 7,888 | 7,697 |
Georgia Power | Residential | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 3,476 | 3,377 | 3,295 |
Georgia Power | Commercial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 2,933 | 3,097 | 3,025 |
Georgia Power | Industrial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 1,197 | 1,360 | 1,321 |
Georgia Power | Other | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 60 | 54 | 56 |
Georgia Power | Natural gas distribution revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Georgia Power | Residential | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Georgia Power | Commercial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Georgia Power | Transportation | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Georgia Power | Industrial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Georgia Power | Other | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Georgia Power | Wholesale electric revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 102 | 123 | 158 |
Georgia Power | PPA energy revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 42 | 60 | 81 |
Georgia Power | PPA capacity revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 50 | 54 | 53 |
Georgia Power | Non-PPA revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 10 | 9 | 24 |
Georgia Power | Other natural gas revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Georgia Power | Gas pipeline investments | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | |
Georgia Power | Wholesale gas services | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Georgia Power | Gas marketing services | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Georgia Power | Other natural gas revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Georgia Power | Other revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 447 | 407 | 236 |
Georgia Power | Other revenue sources | |||
Disaggregation of Revenue [Line Items] | |||
Other | 94 | (10) | 329 |
Georgia Power | Other adjustments | |||
Disaggregation of Revenue [Line Items] | |||
Other | 0 | 0 | 0 |
Mississippi Power | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 1,157 | 1,271 | 1,274 |
Total operating revenues | 1,172 | 1,264 | 1,265 |
Mississippi Power | Retail electric revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 808 | 886 | 902 |
Mississippi Power | Residential | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 260 | 278 | 277 |
Mississippi Power | Commercial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 254 | 291 | 290 |
Mississippi Power | Industrial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 285 | 306 | 326 |
Mississippi Power | Other | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 9 | 11 | 9 |
Mississippi Power | Natural gas distribution revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Mississippi Power | Residential | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Mississippi Power | Commercial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Mississippi Power | Transportation | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Mississippi Power | Industrial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Mississippi Power | Other | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Mississippi Power | Wholesale electric revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 323 | 366 | 350 |
Mississippi Power | PPA energy revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 9 | 11 | 15 |
Mississippi Power | PPA capacity revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 3 | 3 | 6 |
Mississippi Power | Non-PPA revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 311 | 352 | 329 |
Mississippi Power | Other natural gas revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Mississippi Power | Gas pipeline investments | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | |
Mississippi Power | Wholesale gas services | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Mississippi Power | Gas marketing services | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Mississippi Power | Other natural gas revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Mississippi Power | Other revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 26 | 19 | 22 |
Mississippi Power | Other revenue sources | |||
Disaggregation of Revenue [Line Items] | |||
Other | 15 | (7) | (9) |
Mississippi Power | Other adjustments | |||
Disaggregation of Revenue [Line Items] | |||
Other | 0 | 0 | 0 |
Southern Power | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 1,119 | 1,220 | 1,364 |
Total operating revenues | 1,733 | 1,938 | 2,205 |
Southern Power | Retail electric revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Power | Residential | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Power | Commercial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Power | Industrial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Power | Other | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Power | Natural gas distribution revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Power | Residential | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Power | Commercial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Power | Transportation | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Power | Industrial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Power | Other | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Power | Wholesale electric revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 1,105 | 1,208 | 1,351 |
Southern Power | PPA energy revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 570 | 648 | 727 |
Southern Power | PPA capacity revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 296 | 322 | 394 |
Southern Power | Non-PPA revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 239 | 238 | 230 |
Southern Power | Other natural gas revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Power | Gas pipeline investments | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | |
Southern Power | Wholesale gas services | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Power | Gas marketing services | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Power | Other natural gas revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Power | Other revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 14 | 12 | 13 |
Southern Power | Other revenue sources | |||
Disaggregation of Revenue [Line Items] | |||
Other | 614 | 718 | 841 |
Southern Power | Other adjustments | |||
Disaggregation of Revenue [Line Items] | |||
Other | 0 | 0 | 0 |
Southern Company Gas | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 5,039 | 5,598 | 6,914 |
Total operating revenues | 3,434 | 3,792 | 3,909 |
Southern Company Gas | Retail electric revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Company Gas | Residential | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Company Gas | Commercial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Company Gas | Industrial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Company Gas | Other | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Company Gas | Natural gas distribution revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 2,888 | 2,989 | 3,175 |
Southern Company Gas | Residential | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 1,338 | 1,413 | 1,525 |
Southern Company Gas | Commercial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 340 | 389 | 436 |
Southern Company Gas | Transportation | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 971 | 907 | 944 |
Southern Company Gas | Industrial | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 30 | 35 | 40 |
Southern Company Gas | Other | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 209 | 245 | 230 |
Southern Company Gas | Wholesale electric revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Company Gas | PPA energy revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Company Gas | PPA capacity revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Company Gas | Non-PPA revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Company Gas | Other natural gas revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 2,151 | 2,609 | 3,739 |
Southern Company Gas | Gas pipeline investments | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 32 | 32 | |
Southern Company Gas | Wholesale gas services | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 1,727 | 2,095 | 3,083 |
Southern Company Gas | Gas marketing services | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 391 | 440 | 571 |
Southern Company Gas | Other natural gas revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 33 | 42 | 53 |
Southern Company Gas | Other revenues | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from contracts with customers | 0 | 0 | 0 |
Southern Company Gas | Other revenue sources | |||
Disaggregation of Revenue [Line Items] | |||
Other | 2,881 | 3,637 | 3,849 |
Southern Company Gas | Other adjustments | |||
Disaggregation of Revenue [Line Items] | |||
Other | $ (4,486) | $ (5,443) | $ (6,854) |
REVENUE FROM CONTRACTS WITH C_4
REVENUE FROM CONTRACTS WITH CUSTOMERS - Contract Balances (Details) - USD ($) $ in Millions | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] | ||
Accounts Receivables | $ 2,614 | $ 2,413 |
Contract Assets | 158 | 117 |
Contract Liabilities | 61 | 52 |
Revenue Recognized | 33 | 30 |
Unregulated Distributed Generation | ||
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] | ||
Contract Assets | 81 | 40 |
Contract Liabilities | 27 | 28 |
Alabama Power | ||
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] | ||
Accounts Receivables | 632 | 586 |
Contract Assets | 2 | 0 |
Contract Liabilities | 6 | 10 |
Revenue Recognized | 10 | 11 |
Georgia Power | ||
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] | ||
Accounts Receivables | 806 | 688 |
Contract Assets | 71 | 69 |
Contract Liabilities | $ 27 | 13 |
Performance obligation, expected timing of satisfaction | Georgia Power had contract assets primarily related to unregulated service agreements, where payment is contingent on project completion, and fixed retail customer bill programs, where the payment is contingent upon Georgia Power's continued performance and the customer's continued participation in the program over a one-year contract term. Contract liabilities for Georgia Power relate to cash collections recognized in advance of revenue for certain unregulated service agreements. Alabama Power had contract liabilities for outstanding performance obligations primarily related to pole attachment and extended service agreements. | |
Revenue Recognized | $ 8 | 6 |
Mississippi Power | ||
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] | ||
Accounts Receivables | 77 | 79 |
Contract Assets | 0 | 0 |
Contract Liabilities | 1 | 0 |
Southern Power | ||
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] | ||
Accounts Receivables | 112 | 97 |
Contract Assets | 0 | 0 |
Contract Liabilities | 1 | 1 |
Revenue Recognized | 1 | 11 |
Southern Company Gas | ||
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] | ||
Accounts Receivables | 788 | 749 |
Contract Assets | 0 | 0 |
Contract Liabilities | 1 | 1 |
Revenue Recognized | $ 1 | $ 2 |
REVENUE FROM CONTRACTS WITH C_5
REVENUE FROM CONTRACTS WITH CUSTOMERS - Performance Obligations (Details) $ in Millions | Dec. 31, 2020USD ($) |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 547 |
Expected timing of satisfaction | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 395 |
Expected timing of satisfaction | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 338 |
Expected timing of satisfaction | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 326 |
Expected timing of satisfaction | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 306 |
Expected timing of satisfaction | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 2,634 |
Expected timing of satisfaction | |
Alabama Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 33 |
Expected timing of satisfaction | 1 year |
Alabama Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 31 |
Expected timing of satisfaction | 1 year |
Alabama Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 24 |
Expected timing of satisfaction | 1 year |
Alabama Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 7 |
Expected timing of satisfaction | 1 year |
Alabama Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 5 |
Expected timing of satisfaction | 1 year |
Alabama Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 0 |
Expected timing of satisfaction | |
Georgia Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 75 |
Expected timing of satisfaction | 1 year |
Georgia Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 46 |
Expected timing of satisfaction | 1 year |
Georgia Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 35 |
Expected timing of satisfaction | 1 year |
Georgia Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 24 |
Expected timing of satisfaction | 1 year |
Georgia Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 21 |
Expected timing of satisfaction | 1 year |
Georgia Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 42 |
Expected timing of satisfaction | |
Southern Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 285 |
Expected timing of satisfaction | 1 year |
Southern Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 287 |
Expected timing of satisfaction | 1 year |
Southern Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 280 |
Expected timing of satisfaction | 1 year |
Southern Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 296 |
Expected timing of satisfaction | 1 year |
Southern Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 280 |
Expected timing of satisfaction | 1 year |
Southern Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, remaining performance obligation | $ 2,610 |
Expected timing of satisfaction |
PROPERTY, PLANT, AND EQUIPMEN_3
PROPERTY, PLANT, AND EQUIPMENT - Property, Plant and Equipment (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Electric utilities: | ||
Generation | $ 52,179 | $ 50,329 |
Transmission | 12,879 | 12,157 |
Distribution | 20,958 | 19,846 |
General/other | 5,072 | 4,650 |
Electric utilities' plant in service | 91,088 | 86,982 |
Southern Company Gas: | ||
Natural gas distribution utilities transportation and distribution | 14,610 | 13,518 |
Storage facilities | 1,752 | 1,634 |
Other | 1,249 | 1,192 |
Southern Company Gas plant in service | 17,611 | 16,344 |
Other plant in service | 1,817 | 1,788 |
Total plant in service | 110,516 | 105,114 |
Alabama Power | ||
Electric utilities: | ||
Generation | 16,201 | 15,329 |
Transmission | 5,033 | 4,719 |
Distribution | 8,248 | 7,798 |
General/other | 2,334 | 2,177 |
Electric utilities' plant in service | 31,816 | 30,023 |
Southern Company Gas: | ||
Natural gas distribution utilities transportation and distribution | 0 | 0 |
Storage facilities | 0 | 0 |
Other | 0 | 0 |
Southern Company Gas plant in service | 0 | 0 |
Other plant in service | 0 | 0 |
Total plant in service | 31,816 | 30,023 |
Georgia Power | ||
Electric utilities: | ||
Generation | 18,675 | 18,341 |
Transmission | 6,951 | 6,590 |
Distribution | 11,622 | 11,024 |
General/other | 2,434 | 2,182 |
Electric utilities' plant in service | 39,682 | 38,137 |
Southern Company Gas: | ||
Natural gas distribution utilities transportation and distribution | 0 | 0 |
Storage facilities | 0 | 0 |
Other | 0 | 0 |
Southern Company Gas plant in service | 0 | 0 |
Other plant in service | 0 | 0 |
Total plant in service | 39,682 | 38,137 |
Mississippi Power | ||
Electric utilities: | ||
Generation | 2,819 | 2,786 |
Transmission | 856 | 808 |
Distribution | 1,088 | 1,024 |
General/other | 248 | 239 |
Electric utilities' plant in service | 5,011 | 4,857 |
Southern Company Gas: | ||
Natural gas distribution utilities transportation and distribution | 0 | 0 |
Storage facilities | 0 | 0 |
Other | 0 | 0 |
Southern Company Gas plant in service | 0 | 0 |
Other plant in service | 0 | 0 |
Total plant in service | 5,011 | 4,857 |
Southern Power | ||
Electric utilities: | ||
Generation | 13,872 | 13,241 |
Transmission | 0 | 0 |
Distribution | 0 | 0 |
General/other | 32 | 29 |
Electric utilities' plant in service | 13,904 | 13,270 |
Southern Company Gas: | ||
Natural gas distribution utilities transportation and distribution | 0 | 0 |
Storage facilities | 0 | 0 |
Other | 0 | 0 |
Southern Company Gas plant in service | 0 | 0 |
Other plant in service | 0 | 0 |
Total plant in service | 13,904 | 13,270 |
Southern Company Gas | ||
Electric utilities: | ||
Generation | 0 | 0 |
Transmission | 0 | 0 |
Distribution | 0 | 0 |
General/other | 0 | 0 |
Electric utilities' plant in service | 0 | 0 |
Southern Company Gas: | ||
Natural gas distribution utilities transportation and distribution | 14,610 | 13,518 |
Storage facilities | 1,752 | 1,634 |
Other | 1,249 | 1,192 |
Southern Company Gas plant in service | 17,611 | 16,344 |
Other plant in service | 0 | 0 |
Total plant in service | $ 17,611 | $ 16,344 |
PROPERTY, PLANT, AND EQUIPMEN_4
PROPERTY, PLANT, AND EQUIPMENT - Additional Information (Narrative) (Details) | 12 Months Ended |
Dec. 31, 2020 | |
Alabama Power | Maximum | |
Property, Plant and Equipment [Line Items] | |
Regulatory asset amortization period | 28 years |
Alabama Power | Nuclear Outage | |
Property, Plant and Equipment [Line Items] | |
Regulatory asset amortization period | 18 months |
Georgia Power | Maximum | |
Property, Plant and Equipment [Line Items] | |
Regulatory asset amortization period | 32 years |
Georgia Power | Nuclear Outage | Maximum | |
Property, Plant and Equipment [Line Items] | |
Regulatory asset amortization period | 24 months |
Plant Vogtle Units 1 and 2 | Georgia Power | |
Property, Plant and Equipment [Line Items] | |
Unit operating cycle | 18 months |
PROPERTY, PLANT, AND EQUIPMEN_5
PROPERTY, PLANT, AND EQUIPMENT - Composite Straight-Line Rates (Details) - Utility plant in service | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Alabama Power | |||
Property, Plant and Equipment [Line Items] | |||
Composite rate | 2.60% | 3.10% | 3.00% |
Georgia Power | |||
Property, Plant and Equipment [Line Items] | |||
Composite rate | 3.00% | 2.60% | 2.60% |
Mississippi Power | |||
Property, Plant and Equipment [Line Items] | |||
Composite rate | 3.70% | 3.70% | 4.20% |
Southern Company Gas | |||
Property, Plant and Equipment [Line Items] | |||
Composite rate | 2.80% | 2.90% | 2.90% |
PROPERTY, PLANT, AND EQUIPMEN_6
PROPERTY, PLANT, AND EQUIPMENT - Deferred Cloud Implementation Costs (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Property, Plant and Equipment [Line Items] | ||
Deferred cloud implementation costs | $ 16,298 | $ 15,469 |
Deferred Cloud Implementation Costs | ||
Property, Plant and Equipment [Line Items] | ||
Deferred cloud implementation costs | 162 | |
Alabama Power | ||
Property, Plant and Equipment [Line Items] | ||
Deferred cloud implementation costs | 4,262 | 3,680 |
Alabama Power | Deferred Cloud Implementation Costs | ||
Property, Plant and Equipment [Line Items] | ||
Deferred cloud implementation costs | 38 | |
Georgia Power | ||
Property, Plant and Equipment [Line Items] | ||
Deferred cloud implementation costs | 8,297 | 8,028 |
Georgia Power | Deferred Cloud Implementation Costs | ||
Property, Plant and Equipment [Line Items] | ||
Deferred cloud implementation costs | 58 | |
Mississippi Power | ||
Property, Plant and Equipment [Line Items] | ||
Deferred cloud implementation costs | 805 | 775 |
Mississippi Power | Deferred Cloud Implementation Costs | ||
Property, Plant and Equipment [Line Items] | ||
Deferred cloud implementation costs | 7 | |
Southern Power | ||
Property, Plant and Equipment [Line Items] | ||
Deferred cloud implementation costs | 1,150 | 1,870 |
Southern Power | Deferred Cloud Implementation Costs | ||
Property, Plant and Equipment [Line Items] | ||
Deferred cloud implementation costs | 9 | |
Southern Company Gas | ||
Property, Plant and Equipment [Line Items] | ||
Deferred cloud implementation costs | 931 | $ 918 |
Southern Company Gas | Deferred Cloud Implementation Costs | ||
Property, Plant and Equipment [Line Items] | ||
Deferred cloud implementation costs | $ 17 |
PROPERTY, PLANT, AND EQUIPMEN_7
PROPERTY, PLANT, AND EQUIPMENT - Depreciation and Amortization (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Property, Plant and Equipment [Line Items] | ||
Accumulated depreciation | $ 32,397 | $ 30,765 |
Utility plant in service | ||
Property, Plant and Equipment [Line Items] | ||
Accumulated depreciation | 31,600 | 30,000 |
Other plant in service | ||
Property, Plant and Equipment [Line Items] | ||
Accumulated depreciation | $ 817 | 732 |
Other plant in service | Maximum | ||
Property, Plant and Equipment [Line Items] | ||
Depreciation period of original cost | 37 years | |
Southern Company Gas | ||
Property, Plant and Equipment [Line Items] | ||
Accumulated depreciation | $ 4,821 | 4,650 |
Southern Company Gas | Utility plant in service | ||
Property, Plant and Equipment [Line Items] | ||
Accumulated depreciation | 4,600 | 4,500 |
Southern Company Gas | Other plant in service | ||
Property, Plant and Equipment [Line Items] | ||
Accumulated depreciation | $ 195 | $ 155 |
Southern Company Gas | Transportation equipment | Maximum | ||
Property, Plant and Equipment [Line Items] | ||
Depreciation period of original cost | 12 years | |
Southern Company Gas | Transportation equipment | Minimum | ||
Property, Plant and Equipment [Line Items] | ||
Depreciation period of original cost | 5 years | |
Southern Company Gas | Storage facilities | Maximum | ||
Property, Plant and Equipment [Line Items] | ||
Depreciation period of original cost | 75 years | |
Southern Company Gas | Storage facilities | Minimum | ||
Property, Plant and Equipment [Line Items] | ||
Depreciation period of original cost | 30 years | |
Southern Company Gas | Other assets | Maximum | ||
Property, Plant and Equipment [Line Items] | ||
Depreciation period of original cost | 75 years |
PROPERTY, PLANT, AND EQUIPMEN_8
PROPERTY, PLANT, AND EQUIPMENT - Southern Power Useful Lives (Details) - Southern Power - Maximum | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Natural Gas Generating Facility | ||
Property, Plant and Equipment [Line Items] | ||
Useful life | 50 years | 45 years |
Solar Generating Facility | ||
Property, Plant and Equipment [Line Items] | ||
Useful life | 35 years | |
Wind Generating Facility | ||
Property, Plant and Equipment [Line Items] | ||
Useful life | 30 years |
PROPERTY, PLANT, AND EQUIPMEN_9
PROPERTY, PLANT, AND EQUIPMENT - Ownership and Investment in Jointly-Owned Facilities (Details) $ in Millions | 12 Months Ended |
Dec. 31, 2020USD ($)mi | |
Alabama Power | |
Other Ownership Interests [Line Items] | |
Percent Ownership | 14.00% |
Alabama Power | Greene County (natural gas) Units 1 and 2 | |
Other Ownership Interests [Line Items] | |
Percent Ownership | 60.00% |
Plant in Service | $ 189 |
Accumulated Depreciation | 76 |
CWIP | $ 2 |
Alabama Power | Plant Miller (coal) Units 1 and 2 | |
Other Ownership Interests [Line Items] | |
Percent Ownership | 91.80% |
Plant in Service | $ 2,107 |
Accumulated Depreciation | 650 |
CWIP | $ 24 |
Georgia Power | Plant Hatch (nuclear) | |
Other Ownership Interests [Line Items] | |
Percent Ownership | 50.10% |
Plant in Service | $ 1,352 |
Accumulated Depreciation | 624 |
CWIP | $ 37 |
Georgia Power | Plant Vogtle (nuclear) Units 1 and 2 | |
Other Ownership Interests [Line Items] | |
Percent Ownership | 45.70% |
Plant in Service | $ 3,592 |
Accumulated Depreciation | 2,221 |
CWIP | $ 55 |
Georgia Power | Plant Scherer (coal) Units 1 and 2 | |
Other Ownership Interests [Line Items] | |
Percent Ownership | 8.40% |
Plant in Service | $ 279 |
Accumulated Depreciation | 98 |
CWIP | $ 1 |
Georgia Power | Plant Scherer (coal) Unit 3 | |
Other Ownership Interests [Line Items] | |
Percent Ownership | 75.00% |
Plant in Service | $ 1,320 |
Accumulated Depreciation | 520 |
CWIP | $ 4 |
Georgia Power | Plant Wansley (coal) | |
Other Ownership Interests [Line Items] | |
Percent Ownership | 53.50% |
Plant in Service | $ 1,068 |
Accumulated Depreciation | 418 |
CWIP | $ 10 |
Georgia Power | Rocky Mountain (pumped storage) | |
Other Ownership Interests [Line Items] | |
Percent Ownership | 25.40% |
Plant in Service | $ 183 |
Accumulated Depreciation | 144 |
CWIP | $ 1 |
Mississippi Power | Plant Daniel (coal) Units 1 and 2 | |
Other Ownership Interests [Line Items] | |
Percent Ownership | 50.00% |
Plant in Service | $ 775 |
Accumulated Depreciation | 238 |
CWIP | $ 15 |
Southern Company Gas | Dalton Pipeline (natural gas pipeline) | |
Other Ownership Interests [Line Items] | |
Percent Ownership | 50.00% |
Plant in Service | $ 271 |
Accumulated Depreciation | 15 |
CWIP | $ 0 |
Pipeline infrastructure (miles) | mi | 115 |
Agreement to lease undivided ownership (percent) | 50.00% |
Future minimum payments receivable | $ 26 |
Alabama Power | Mississippi Power | Greene County (natural gas) Units 1 and 2 | |
Other Ownership Interests [Line Items] | |
Percent Ownership | 40.00% |
Plant in Service | $ 122 |
Accumulated Depreciation | 54 |
CWIP | $ 1 |
PROPERTY, PLANT, AND EQUIPME_10
PROPERTY, PLANT, AND EQUIPMENT - Joint Ownership Agreements (Narrative) (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Property, Plant and Equipment [Line Items] | ||
Construction work in progress | $ 8,697 | $ 7,880 |
Georgia Power | ||
Property, Plant and Equipment [Line Items] | ||
Construction work in progress | $ 6,857 | $ 5,650 |
Plant Vogtle Units 3 And 4 | Georgia Power | ||
Property, Plant and Equipment [Line Items] | ||
Percent ownership | 45.70% | |
Construction work in progress | $ 7,300 |
PROPERTY, PLANT, AND EQUIPME_11
PROPERTY, PLANT, AND EQUIPMENT - Assets Subject to Lien (Narrative) (Details) $ in Millions | Dec. 31, 2020USD ($) |
Mississippi Power | Chevron | |
Property, Plant and Equipment [Line Items] | |
Net book value of co-generation assets | $ 138 |
ASSET RETIREMENT OBLIGATIONS -
ASSET RETIREMENT OBLIGATIONS - Details of AROs Included in the Balance Sheets (Details) - USD ($) $ in Millions | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
Balance at beginning of year | $ 9,786 | $ 9,394 |
Liabilities incurred | 19 | 37 |
Liabilities settled | (442) | (328) |
Accretion | 409 | 402 |
Cash flow revisions | 912 | 281 |
Balance at end of year | 10,684 | 9,786 |
Alabama Power | ||
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
Balance at beginning of year | 3,540 | 3,210 |
Liabilities incurred | 0 | 0 |
Liabilities settled | (219) | (127) |
Accretion | 152 | 145 |
Cash flow revisions | 501 | 312 |
Balance at end of year | 3,974 | 3,540 |
Georgia Power | ||
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
Balance at beginning of year | 5,784 | 5,829 |
Liabilities incurred | 10 | 35 |
Liabilities settled | (185) | (151) |
Accretion | 238 | 243 |
Cash flow revisions | 418 | (172) |
Balance at end of year | 6,265 | 5,784 |
Mississippi Power | ||
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
Balance at beginning of year | 190 | 160 |
Liabilities incurred | 0 | 1 |
Liabilities settled | (22) | (35) |
Accretion | 8 | 7 |
Cash flow revisions | 0 | 57 |
Balance at end of year | 176 | 190 |
Southern Power | ||
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
Balance at beginning of year | 89 | 84 |
Liabilities incurred | 9 | 1 |
Liabilities settled | 0 | 0 |
Accretion | 4 | 4 |
Cash flow revisions | (7) | 0 |
Balance at end of year | $ 95 | $ 89 |
ASSET RETIREMENT OBLIGATIONS _2
ASSET RETIREMENT OBLIGATIONS - Narrative (Details) - USD ($) $ in Millions | 1 Months Ended | 12 Months Ended | ||
Sep. 30, 2020 | Dec. 31, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | |
Alabama Power | ||||
Jointly Owned Utility Plant Interests [Line Items] | ||||
Increase (decrease) to AROs | $ 501 | $ 312 | ||
Estimated inflation rate | 4.50% | |||
Estimated trust earnings rate | 7.00% | |||
Alabama Power | Internal reserves | ||||
Jointly Owned Utility Plant Interests [Line Items] | ||||
Accumulated provisions for decommissioning | $ 16 | $ 15 | 16 | |
Mississippi Power | ||||
Jointly Owned Utility Plant Interests [Line Items] | ||||
Increase (decrease) to AROs | 57 | |||
Georgia Power | ||||
Jointly Owned Utility Plant Interests [Line Items] | ||||
Increase (decrease) to AROs | $ 411 | (174) | ||
Fair market value of securities on loan and pledged to creditors | 28 | 44 | 28 | |
Fair value of collateral received | $ 29 | $ 45 | 29 | |
Estimated inflation rate | 2.75% | |||
Estimated trust earnings rate | 4.75% | |||
Georgia Power | Plant Hatch and Plant Vogtle Units 1 And 2 | ||||
Jointly Owned Utility Plant Interests [Line Items] | ||||
Annual decommissioning cost for ratemaking | $ 4 | $ 5 |
ASSET RETIREMENT OBLIGATIONS _3
ASSET RETIREMENT OBLIGATIONS - Investment Securities in the Funds (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Marketable Securities [Line Items] | ||
Total investment securities in the Funds | $ 2,301 | $ 2,034 |
Equity securities | ||
Marketable Securities [Line Items] | ||
Total investment securities in the Funds | 1,339 | 1,159 |
Debt securities | ||
Marketable Securities [Line Items] | ||
Total investment securities in the Funds | 851 | 798 |
Other securities | ||
Marketable Securities [Line Items] | ||
Total investment securities in the Funds | 111 | 77 |
Alabama Power | ||
Marketable Securities [Line Items] | ||
Total investment securities in the Funds | 1,156 | 1,021 |
Alabama Power | Equity securities | ||
Marketable Securities [Line Items] | ||
Total investment securities in the Funds | 842 | 743 |
Alabama Power | Debt securities | ||
Marketable Securities [Line Items] | ||
Total investment securities in the Funds | 231 | 218 |
Alabama Power | Other securities | ||
Marketable Securities [Line Items] | ||
Total investment securities in the Funds | 83 | 60 |
Georgia Power | ||
Marketable Securities [Line Items] | ||
Total investment securities in the Funds | 1,145 | 1,013 |
Georgia Power | Equity securities | ||
Marketable Securities [Line Items] | ||
Total investment securities in the Funds | 497 | 416 |
Georgia Power | Debt securities | ||
Marketable Securities [Line Items] | ||
Total investment securities in the Funds | 620 | 580 |
Georgia Power | Other securities | ||
Marketable Securities [Line Items] | ||
Total investment securities in the Funds | $ 28 | $ 17 |
ASSET RETIREMENT OBLIGATIONS _4
ASSET RETIREMENT OBLIGATIONS - Fair Value Increases (Decreases) of the Funds (Details) - Securities held in the Funds - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Fair value increases (decreases) | |||
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items] | |||
Fair value increases (decreases) of the Funds | $ 280 | $ 344 | $ (67) |
Unrealized gains (losses) | |||
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items] | |||
Fair value increases (decreases) of the Funds | 220 | 259 | (183) |
Alabama Power | Fair value increases (decreases) | |||
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items] | |||
Fair value increases (decreases) of the Funds | 142 | 194 | (38) |
Alabama Power | Unrealized gains (losses) | |||
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items] | |||
Fair value increases (decreases) of the Funds | 121 | 149 | (96) |
Georgia Power | Fair value increases (decreases) | |||
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items] | |||
Fair value increases (decreases) of the Funds | 138 | 150 | (29) |
Georgia Power | Unrealized gains (losses) | |||
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items] | |||
Fair value increases (decreases) of the Funds | $ 99 | $ 110 | $ (87) |
ASSET RETIREMENT OBLIGATIONS _5
ASSET RETIREMENT OBLIGATIONS - Accumulated Provisions for the External Decommissioning Trust Funds (Details) - External decommissioning trust funds - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Georgia Power | ||
Public Utilities, General Disclosures [Line Items] | ||
Accumulated provisions for decommissioning | $ 1,145 | $ 1,013 |
Plant Farley | Alabama Power | ||
Public Utilities, General Disclosures [Line Items] | ||
Accumulated provisions for decommissioning | 1,156 | 1,021 |
Plant Hatch | Georgia Power | ||
Public Utilities, General Disclosures [Line Items] | ||
Accumulated provisions for decommissioning | 716 | 634 |
Plant Vogtle Units 1 and 2 | Georgia Power | ||
Public Utilities, General Disclosures [Line Items] | ||
Accumulated provisions for decommissioning | $ 429 | $ 379 |
ASSET RETIREMENT OBLIGATIONS _6
ASSET RETIREMENT OBLIGATIONS - Estimated Costs of Decommissioning (Details) $ in Millions | 12 Months Ended |
Dec. 31, 2020USD ($) | |
Alabama Power | Plant Farley | |
Public Utilities, General Disclosures [Line Items] | |
Decommissioning periods: Beginning year | 2037 |
Decommissioning periods: Completion year | 2076 |
Site study costs | $ 1,720 |
Alabama Power | Radiated structures | Plant Farley | |
Public Utilities, General Disclosures [Line Items] | |
Site study costs | 1,234 |
Alabama Power | Spent fuel management | Plant Farley | |
Public Utilities, General Disclosures [Line Items] | |
Site study costs | 387 |
Alabama Power | Non-radiated structures | Plant Farley | |
Public Utilities, General Disclosures [Line Items] | |
Site study costs | $ 99 |
Georgia Power | Plant Hatch | |
Public Utilities, General Disclosures [Line Items] | |
Decommissioning periods: Beginning year | 2034 |
Decommissioning periods: Completion year | 2075 |
Site study costs | $ 962 |
Georgia Power | Plant Vogtle Units 1 and 2 | |
Public Utilities, General Disclosures [Line Items] | |
Decommissioning periods: Beginning year | 2047 |
Decommissioning periods: Completion year | 2079 |
Site study costs | $ 842 |
Georgia Power | Radiated structures | Plant Hatch | |
Public Utilities, General Disclosures [Line Items] | |
Site study costs | 734 |
Georgia Power | Radiated structures | Plant Vogtle Units 1 and 2 | |
Public Utilities, General Disclosures [Line Items] | |
Site study costs | 601 |
Georgia Power | Spent fuel management | Plant Hatch | |
Public Utilities, General Disclosures [Line Items] | |
Site study costs | 172 |
Georgia Power | Spent fuel management | Plant Vogtle Units 1 and 2 | |
Public Utilities, General Disclosures [Line Items] | |
Site study costs | 162 |
Georgia Power | Non-radiated structures | Plant Hatch | |
Public Utilities, General Disclosures [Line Items] | |
Site study costs | 56 |
Georgia Power | Non-radiated structures | Plant Vogtle Units 1 and 2 | |
Public Utilities, General Disclosures [Line Items] | |
Site study costs | $ 79 |
CONSOLIDATED ENTITIES AND EQU_3
CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS - SEGCO Equity Method Investments Narrative (Details) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020USD ($)MW | Dec. 31, 2019USD ($) | Dec. 31, 2018USD ($) | |
Alabama Power | |||
Jointly Owned Utility Plant Interests [Line Items] | |||
Ownership percentage, equity method investment | 50.00% | ||
Percent ownership | 14.00% | ||
Alabama Power | SEGCO | |||
Jointly Owned Utility Plant Interests [Line Items] | |||
Total megawatt capacity (in MWs) | MW | 1,020 | ||
Share of purchased power | $ 67 | $ 93 | $ 102 |
Dividends paid by equity method investment | $ 12 | 14 | 18 |
Georgia Power | |||
Jointly Owned Utility Plant Interests [Line Items] | |||
Ownership percentage, equity method investment | 50.00% | ||
Georgia Power | SEGCO | |||
Jointly Owned Utility Plant Interests [Line Items] | |||
Share of purchased power | $ 69 | $ 95 | $ 105 |
SEGCO | Alabama Power | |||
Jointly Owned Utility Plant Interests [Line Items] | |||
Percent ownership | 86.00% |
CONSOLIDATED ENTITIES AND EQU_4
CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS - SPC Noncontrolling Interests and VIEs Narrative (Details) $ in Millions | 1 Months Ended | 12 Months Ended | |||
Dec. 31, 2018USD ($)investorwind_farm | May 31, 2018 | Dec. 31, 2020USD ($) | Dec. 31, 2018USD ($)investorwind_farmoperating_facility | Dec. 31, 2019USD ($) | |
Redeemable Noncontrolling Interest [Line Items] | |||||
Assets | $ 116,914 | $ 122,935 | $ 116,914 | $ 118,700 | |
Liabilities | 90,410 | 86,650 | |||
Equity investments in unconsolidated subsidiaries | 1,362 | 1,303 | |||
Southern Power | |||||
Redeemable Noncontrolling Interest [Line Items] | |||||
Assets | 13,235 | 14,300 | |||
Liabilities | 6,604 | 7,678 | |||
Number of wind facilities | operating_facility | 8 | ||||
Equity investments in unconsolidated subsidiaries | $ 19 | 28 | |||
Southern Power | SP Solar Holdings I, LP | |||||
Redeemable Noncontrolling Interest [Line Items] | |||||
Sale of equity interest in limited partnership | 33.00% | ||||
Southern Power | SP Wind | |||||
Redeemable Noncontrolling Interest [Line Items] | |||||
Sale of equity interest in limited partnership | 100.00% | ||||
Wholly Owned Subsidiary Of Southern Power | Southern Power | SP Solar Holdings I, LP | |||||
Redeemable Noncontrolling Interest [Line Items] | |||||
Ownership interest | 66.00% | ||||
Wholly Owned Subsidiary Of Southern Power | Southern Power | SP Wind | |||||
Redeemable Noncontrolling Interest [Line Items] | |||||
Ownership interest | 100.00% | ||||
SP Solar Holdings I, LP | Southern Power | |||||
Redeemable Noncontrolling Interest [Line Items] | |||||
Distribution made to limited partner, cash distributions paid, percentage | 67.00% | ||||
SP Solar Holdings I, LP | Southern Power | SP Solar Holdings I, LP | |||||
Redeemable Noncontrolling Interest [Line Items] | |||||
Sale of equity interest in limited partnership | 33.00% | ||||
SP Solar Holdings I, LP | Global Atlantic | |||||
Redeemable Noncontrolling Interest [Line Items] | |||||
Distribution made to limited partner, cash distributions paid, percentage | 33.00% | ||||
SP Wind | |||||
Redeemable Noncontrolling Interest [Line Items] | |||||
Number of wind facilities | wind_farm | 8 | 8 | |||
SP Wind | Southern Power | |||||
Redeemable Noncontrolling Interest [Line Items] | |||||
Distribution made to limited partner, cash distributions paid, percentage | 60.00% | ||||
Number of financial investors | investor | 3 | ||||
SP Wind | Southern Power | SP Wind | |||||
Redeemable Noncontrolling Interest [Line Items] | |||||
Number of financial investors | investor | 3 | ||||
SP Wind | Financial Investors | |||||
Redeemable Noncontrolling Interest [Line Items] | |||||
Distribution made to limited partner, cash distributions paid, percentage | 40.00% | 40.00% | |||
General Partner | Wholly Owned Subsidiary Of Southern Power | Southern Power | SP Solar Holdings I, LP | |||||
Redeemable Noncontrolling Interest [Line Items] | |||||
Ownership interest | 1.00% | ||||
Variable Interest Entity, Primary Beneficiary | SP Solar Holdings I, LP | Southern Power | |||||
Redeemable Noncontrolling Interest [Line Items] | |||||
Assets | $ 6,100 | 6,400 | |||
Liabilities | 387 | 381 | |||
Noncontrolling interests related to other partners' interest | 1,100 | ||||
Variable Interest Entity, Primary Beneficiary | SP Wind | Southern Power | |||||
Redeemable Noncontrolling Interest [Line Items] | |||||
Assets | 2,400 | 2,500 | |||
Liabilities | 138 | 128 | |||
Noncontrolling interests related to other partners' interest | 43 | 45 | |||
Variable Interest Entity, Primary Beneficiary | Other Variable Interest Entities | Southern Power | |||||
Redeemable Noncontrolling Interest [Line Items] | |||||
Assets | 1,100 | ||||
Liabilities | 110 | 104 | |||
Noncontrolling interests related to other partners' interest | $ 454 | $ 409 |
CONSOLIDATED ENTITIES AND EQU_5
CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS - Balance Sheet Information (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Schedule of Equity Method Investments [Line Items] | ||
Equity investments in unconsolidated subsidiaries | $ 1,362 | $ 1,303 |
Southern Company Gas | ||
Schedule of Equity Method Investments [Line Items] | ||
Equity investments in unconsolidated subsidiaries | 1,290 | 1,251 |
SNG | Southern Company Gas | ||
Schedule of Equity Method Investments [Line Items] | ||
Equity investments in unconsolidated subsidiaries | 1,167 | 1,137 |
PennEast Pipeline | Southern Company Gas | ||
Schedule of Equity Method Investments [Line Items] | ||
Equity investments in unconsolidated subsidiaries | 91 | 82 |
Other | Southern Company Gas | ||
Schedule of Equity Method Investments [Line Items] | ||
Equity investments in unconsolidated subsidiaries | $ 32 | $ 32 |
CONSOLIDATED ENTITIES AND EQU_6
CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS - Income Statement Information (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Schedule of Equity Method Investments [Line Items] | |||
Earnings from equity method investments | $ 153 | $ 162 | $ 148 |
Southern Company Gas | |||
Schedule of Equity Method Investments [Line Items] | |||
Earnings from equity method investments | 141 | 157 | 148 |
Southern Company Gas | SNG | |||
Schedule of Equity Method Investments [Line Items] | |||
Earnings from equity method investments | 129 | 141 | 131 |
Southern Company Gas | Atlantic Coast Pipeline | |||
Schedule of Equity Method Investments [Line Items] | |||
Earnings from equity method investments | 3 | 13 | 7 |
Southern Company Gas | Penn East Pipeline | |||
Schedule of Equity Method Investments [Line Items] | |||
Earnings from equity method investments | 7 | 6 | 5 |
Southern Company Gas | Other | |||
Schedule of Equity Method Investments [Line Items] | |||
Earnings from equity method investments | $ 2 | $ (3) | $ 5 |
FINANCING - Long-Term Debt (Det
FINANCING - Long-Term Debt (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Debt Instrument [Line Items] | ||
Long-term debt, gross | $ 48,349 | $ 44,561 |
Finance lease obligations | 231 | 226 |
Unamortized fair value adjustment | 393 | 430 |
Unamortized debt premium (discount), net | (201) | (152) |
Unamortized debt issuance expense | (237) | (247) |
Total long-term debt | 48,580 | 44,787 |
Less: Amount due within one year | 3,507 | 2,989 |
Long-Term Debt | $ 45,073 | 41,798 |
Senior notes | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 3.78% | |
Long-term debt, gross | $ 30,850 | 30,023 |
Junior subordinated notes | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 4.30% | |
Long-term debt, gross | $ 7,295 | 5,295 |
FFB loans | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 2.92% | |
Long-term debt, gross | $ 4,618 | 3,843 |
Pollution control revenue bonds | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 1.11% | |
Long-term debt, gross | $ 2,675 | 2,963 |
First mortgage bonds | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 3.71% | |
Long-term debt, gross | $ 1,900 | 1,575 |
Other revenue bonds | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 6.45% | |
Long-term debt, gross | $ 320 | 320 |
Affiliated trusts | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 3.33% | |
Long-term debt, gross | $ 206 | 206 |
Medium-term notes | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 7.88% | |
Long-term debt, gross | $ 160 | 160 |
Other long-term debt | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 0.83% | |
Long-term debt, gross | $ 370 | 145 |
Alabama Power | ||
Debt Instrument [Line Items] | ||
Long-term debt, gross | 8,864 | 8,517 |
Finance lease obligations | 5 | 4 |
Unamortized debt premium (discount), net | (16) | (14) |
Unamortized debt issuance expense | (56) | (55) |
Total long-term debt | 8,869 | 8,521 |
Less: Amount due within one year | 311 | 251 |
Long-Term Debt | $ 8,558 | 8,270 |
Percent ownership | 14.00% | |
Alabama Power | Senior notes | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 4.03% | |
Long-term debt, gross | $ 7,625 | 7,275 |
Alabama Power | Pollution control revenue bonds | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 0.53% | |
Long-term debt, gross | $ 1,060 | 1,060 |
Alabama Power | Affiliated trusts | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 3.33% | |
Long-term debt, gross | $ 206 | 206 |
Alabama Power | Other long-term debt | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 1.20% | |
Long-term debt, gross | $ 45 | 45 |
Georgia Power | ||
Debt Instrument [Line Items] | ||
Long-term debt, gross | 12,825 | 11,660 |
Finance lease obligations | 145 | 156 |
Unamortized debt premium (discount), net | (12) | (7) |
Unamortized debt issuance expense | (114) | (117) |
Total long-term debt | 12,970 | 11,816 |
Less: Amount due within one year | 542 | 1,025 |
Long-Term Debt | $ 12,428 | 10,791 |
Georgia Power | Plant Vogtle Units 3 And 4 | ||
Debt Instrument [Line Items] | ||
Percent ownership | 45.70% | |
Georgia Power | Senior notes | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 3.59% | |
Long-term debt, gross | $ 6,400 | 5,850 |
Georgia Power | Junior subordinated notes | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 5.00% | |
Long-term debt, gross | $ 270 | 270 |
Georgia Power | FFB loans | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 2.92% | |
Long-term debt, gross | $ 4,618 | 3,843 |
Georgia Power | Pollution control revenue bonds | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 1.47% | |
Long-term debt, gross | $ 1,538 | 1,821 |
Georgia Power | Other long-term debt | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 0.65% | |
Long-term debt, gross | $ 125 | 0 |
Mississippi Power | ||
Debt Instrument [Line Items] | ||
Long-term debt, gross | 1,400 | 1,589 |
Finance lease obligations | 19 | 0 |
Unamortized debt premium (discount), net | 11 | 19 |
Unamortized debt issuance expense | (7) | (8) |
Total long-term debt | 1,419 | 1,589 |
Less: Amount due within one year | 406 | 281 |
Long-Term Debt | $ 1,013 | 1,308 |
Mississippi Power | Senior notes | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 4.23% | |
Long-term debt, gross | $ 900 | 1,175 |
Mississippi Power | Pollution control revenue bonds | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 1.86% | |
Long-term debt, gross | $ 76 | 83 |
Mississippi Power | Other revenue bonds | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 6.45% | |
Long-term debt, gross | $ 320 | 320 |
Mississippi Power | Other long-term debt | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 1.00% | |
Long-term debt, gross | $ 100 | 0 |
Southern Power | ||
Debt Instrument [Line Items] | ||
Long-term debt, gross | 3,692 | 4,398 |
Finance lease obligations | 0 | 0 |
Unamortized debt premium (discount), net | (6) | (8) |
Unamortized debt issuance expense | (16) | (19) |
Total long-term debt | 3,692 | 4,398 |
Less: Amount due within one year | 299 | 824 |
Long-Term Debt | 3,393 | 3,574 |
Fair value gain (loss) | 109 | (5) |
Derivative notional amount, receive | $ 1,100 | |
Southern Power | Senior notes | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 3.96% | |
Long-term debt, gross | $ 3,714 | 4,425 |
Southern Company Gas | ||
Debt Instrument [Line Items] | ||
Long-term debt, gross | 6,626 | 5,845 |
Finance lease obligations | 0 | 0 |
Unamortized fair value adjustment | 393 | 430 |
Unamortized debt premium (discount), net | (27) | (20) |
Total long-term debt | 6,626 | 5,845 |
Less: Amount due within one year | 333 | 0 |
Long-Term Debt | $ 6,293 | 5,845 |
Southern Company Gas | Senior notes | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 4.01% | |
Long-term debt, gross | $ 4,200 | 3,700 |
Southern Company Gas | First mortgage bonds | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 3.71% | |
Long-term debt, gross | $ 1,900 | 1,575 |
Southern Company Gas | Medium-term notes | ||
Debt Instrument [Line Items] | ||
Weighted average interest rate | 7.88% | |
Long-term debt, gross | $ 160 | 160 |
Mississippi Business Finance Corporation Taxable Revenue Bonds | Mississippi Power | Corporate bonds | ||
Debt Instrument [Line Items] | ||
Long-term debt | $ 270 | $ 270 |
Quarterly interest rate | 7.13% | 7.13% |
Tax-exempt Revenue Bonds | Mississippi Power | Secured Debt | ||
Debt Instrument [Line Items] | ||
Long-term debt | $ 50 | $ 50 |
FINANCING - Maturities of Long-
FINANCING - Maturities of Long-Term Debt (Details) $ in Millions | Dec. 31, 2020USD ($) |
Debt Disclosure [Line Items] | |
2021 | $ 3,506 |
2022 | 3,707 |
2023 | 3,131 |
2024 | 509 |
2025 | 1,191 |
Alabama Power | |
Debt Disclosure [Line Items] | |
2021 | 311 |
2022 | 751 |
2023 | 301 |
2024 | 22 |
2025 | 250 |
Georgia Power | |
Debt Disclosure [Line Items] | |
2021 | 542 |
2022 | 488 |
2023 | 889 |
2024 | 491 |
2025 | 138 |
Mississippi Power | |
Debt Disclosure [Line Items] | |
2021 | 406 |
2022 | 16 |
2023 | 1 |
2024 | 1 |
2025 | 12 |
Long-term debt maturing in 2040 intended to be repaid in 2021 | 50 |
Long-term debt maturing in 2023 intended to be repaid in 2021 | 25 |
Southern Power | |
Debt Disclosure [Line Items] | |
2021 | 300 |
2022 | 677 |
2023 | 290 |
2024 | 0 |
2025 | 500 |
Southern Company Gas | |
Debt Disclosure [Line Items] | |
2021 | 330 |
2022 | 46 |
2023 | 400 |
2024 | 0 |
2025 | $ 300 |
FINANCING - DOE Loan Guarantee
FINANCING - DOE Loan Guarantee Borrowings (Details) - USD ($) | 1 Months Ended | 12 Months Ended | ||||||
Dec. 31, 2020 | Jun. 30, 2020 | Mar. 31, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Jun. 30, 2019 | Aug. 31, 2018 | |
Debt Instrument [Line Items] | ||||||||
Line of credit facility, maximum borrowing capacity | $ 7,733,000,000 | $ 7,733,000,000 | ||||||
Georgia Power | ||||||||
Debt Instrument [Line Items] | ||||||||
Percent of eligible project costs (may not exceed) | 70.00% | |||||||
Principal amortization payments | 73,000,000 | $ 0 | $ 0 | |||||
Line of credit facility, maximum borrowing capacity | $ 1,750,000,000 | $ 1,750,000,000 | ||||||
Basis spread on variable rate | 0.375% | |||||||
Amortization period | 5 years | |||||||
Plant Vogtle Units 3 And 4 | Georgia Power | ||||||||
Debt Instrument [Line Items] | ||||||||
Percent ownership | 45.70% | 45.70% | ||||||
FFB Loan | Georgia Power | ||||||||
Debt Instrument [Line Items] | ||||||||
Eligible project costs to be reimbursed | $ 5,130,000,000 | |||||||
Proceeds from lines of credit | $ 329,000,000 | $ 519,000,000 | ||||||
Fixed stated interest rate of debt obligation | 1.737% | 1.737% | 1.652% | |||||
Principal amortization payments | $ 73,000,000 | |||||||
Line of credit facility, maximum borrowing capacity | $ 4,600,000,000 | $ 4,600,000,000 | $ 3,800,000,000 | |||||
Additional FFB Credit Facility | Georgia Power | ||||||||
Debt Instrument [Line Items] | ||||||||
Funds received under guarantee settlement agreement, less customer refunds | $ 1,492,000,000 | |||||||
Plant Vogtle Units 3 And 4 | Georgia Power | ||||||||
Debt Instrument [Line Items] | ||||||||
Percent ownership | 45.70% | 45.70% | ||||||
Ownership interest percentage required for voting for continuing construction | 90.00% |
FINANCING - Equity Units (Detai
FINANCING - Equity Units (Details) - USD ($) | 1 Months Ended | |
Aug. 31, 2019 | Dec. 31, 2020 | |
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items] | ||
Number of shares indexed (in shares) | 34,500,000 | |
Equity units, per unit issuance price (in dollars per share) | $ 50 | |
Proceeds from issuance of mandatory redeemable capital securities | $ 1,682,000,000 | |
Maximum number of shares (in shares) | 30,200,000 | |
Junior subordinated notes | ||
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items] | ||
Equity units, settlement terms, contract adjustment payments, accretion period | 3 years | |
Series 2019A and Series 2019B Remarketable Junior Subordinated Notes | Junior subordinated notes | ||
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items] | ||
Equity units, annual distribution rate | 6.75% | |
Quarterly interest rate | 2.70% | |
Interest rate | 4.05% | |
Purchase contract adjustment liability | $ 198,000,000 | $ 119,000,000 |
Purchase contract adjustment liability, current | $ 67,000,000 | |
Series 2019A Remarketable Junior Subordinated Notes | Junior subordinated notes | ||
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items] | ||
Debt face amount | $ 1,725,000,000 | |
Equity units, percentage interest in attached debt instrument | 0.0025% | |
Series 2019B Remarketable Junior Subordinated Notes | Junior subordinated notes | ||
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items] | ||
Equity units, percentage interest in attached debt instrument | 0.0025% | |
Anti-Dilution Scenario One | ||
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items] | ||
Equity units, conversion ratio (in shares) | 0.7284 | |
Anti-Dilution Scenario One | Minimum | ||
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items] | ||
Equity units, stock price upper threshold (in dollars per share) | $ 68.64 | |
Anti-Dilution Scenario Two | ||
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items] | ||
Equity units, per unit issuance price (in dollars per share) | 50 | |
Anti-Dilution Scenario Two | Minimum | ||
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items] | ||
Equity units, stock price lower threshold (in dollars per share) | 57.20 | |
Anti-Dilution Scenario Two | Maximum | ||
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items] | ||
Equity units, stock price upper threshold (in dollars per share) | $ 68.64 | |
Anti-Dilution Scenario Three | ||
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items] | ||
Equity units, conversion ratio (in shares) | 0.8741 | |
Anti-Dilution Scenario Three | Maximum | ||
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items] | ||
Equity units, stock price lower threshold (in dollars per share) | $ 57.20 |
FINANCING - Bank Credit Arrange
FINANCING - Bank Credit Arrangements (Details) - USD ($) | Dec. 31, 2020 | Nov. 30, 2020 |
Line of Credit Facility [Line Items] | ||
Expires, 2021 | $ 33,000,000 | |
Expires, 2022 | 675,000,000 | |
Expires, 2023 | 125,000,000 | |
Expires, 2024 | 6,900,000,000 | |
Total | 7,733,000,000 | |
Unused | 7,671,000,000 | |
Due within One Year | 33,000,000 | |
Southern Company | ||
Line of Credit Facility [Line Items] | ||
Expires, 2021 | 0 | |
Expires, 2022 | 0 | |
Expires, 2023 | 0 | |
Expires, 2024 | 2,000,000,000 | |
Total | 2,000,000,000 | |
Unused | 1,999,000,000 | |
Due within One Year | 0 | |
Alabama Power | ||
Line of Credit Facility [Line Items] | ||
Expires, 2021 | 3,000,000 | |
Expires, 2022 | 525,000,000 | |
Expires, 2023 | 0 | |
Expires, 2024 | 800,000,000 | |
Total | 1,328,000,000 | |
Unused | 1,328,000,000 | |
Due within One Year | 3,000,000 | |
Georgia Power | ||
Line of Credit Facility [Line Items] | ||
Expires, 2021 | 0 | |
Expires, 2022 | 0 | |
Expires, 2023 | 0 | |
Expires, 2024 | 1,750,000,000 | |
Total | 1,750,000,000 | |
Unused | 1,728,000,000 | |
Due within One Year | 0 | |
Mississippi Power | ||
Line of Credit Facility [Line Items] | ||
Expires, 2021 | 0 | |
Expires, 2022 | 150,000,000 | |
Expires, 2023 | 125,000,000 | |
Expires, 2024 | 0 | |
Total | 275,000,000 | |
Unused | 250,000,000 | |
Due within One Year | 0 | |
Southern Power | ||
Line of Credit Facility [Line Items] | ||
Expires, 2021 | 0 | |
Expires, 2022 | 0 | |
Expires, 2023 | 0 | |
Expires, 2024 | 600,000,000 | |
Total | 600,000,000 | |
Unused | 591,000,000 | |
Due within One Year | 0 | |
Southern Power | Continuing Letter of Credit Facility A | ||
Line of Credit Facility [Line Items] | ||
Expires, 2023 | 75,000,000 | |
Total | $ 120,000,000 | |
Unused | 5,000,000 | |
Southern Power | Continuing Letter of Credit Facility B | ||
Line of Credit Facility [Line Items] | ||
Expires, 2023 | 60,000,000 | |
Unused | 11,000,000 | |
Southern Company Gas | ||
Line of Credit Facility [Line Items] | ||
Expires, 2021 | 0 | |
Expires, 2022 | 0 | |
Expires, 2023 | 0 | |
Expires, 2024 | 1,750,000,000 | |
Total | 1,750,000,000 | |
Unused | 1,745,000,000 | |
Due within One Year | 0 | |
Other Subsidiaries | ||
Line of Credit Facility [Line Items] | ||
Expires, 2021 | 30,000,000 | |
Expires, 2022 | 0 | |
Expires, 2023 | 0 | |
Expires, 2024 | 0 | |
Total | 30,000,000 | |
Unused | 30,000,000 | |
Due within One Year | 30,000,000 | |
Southern Company Gas Capital | ||
Line of Credit Facility [Line Items] | ||
Total | 1,250,000,000 | |
Nicor Gas | ||
Line of Credit Facility [Line Items] | ||
Total | $ 500,000,000 |
FINANCING - Bank Credit Arran_2
FINANCING - Bank Credit Arrangements Narrative (Details) - USD ($) $ in Millions | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Debt Disclosure [Line Items] | ||
Ratio of indebtedness to capitalization, debt covenant, required | 70.00% | |
Amount of variable rate pollution control revenue bonds outstanding requiring liquidity support | $ 1,400 | |
Other Subsidiaries | ||
Debt Disclosure [Line Items] | ||
Ratio of indebtedness to capitalization, debt covenant, required | 65.00% | |
Alabama Power | ||
Debt Disclosure [Line Items] | ||
Amount of variable rate pollution control revenue bonds outstanding requiring liquidity support | $ 854 | |
Georgia Power | ||
Debt Disclosure [Line Items] | ||
Amount of variable rate pollution control revenue bonds outstanding requiring liquidity support | 550 | |
Remarketed pollution control bonds | 174 | |
Mississippi Power | ||
Debt Disclosure [Line Items] | ||
Amount of variable rate pollution control revenue bonds outstanding requiring liquidity support | 34 | |
Remarketed pollution control bonds | 50 | |
Southern Power | Power Purchase Agreement | ||
Debt Disclosure [Line Items] | ||
Debt instrument, collateral amount | $ 105 | $ 104 |
FINANCING - Notes Payable (Deta
FINANCING - Notes Payable (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Short-term Debt [Line Items] | ||
Amount Outstanding | $ 609 | $ 2,055 |
Weighted Average Interest Rate | 0.30% | 2.10% |
Commercial paper | ||
Short-term Debt [Line Items] | ||
Amount Outstanding | $ 609 | $ 1,705 |
Weighted Average Interest Rate | 0.30% | 2.10% |
Short-term bank debt | ||
Short-term Debt [Line Items] | ||
Amount Outstanding | $ 0 | $ 350 |
Weighted Average Interest Rate | 0.00% | 2.30% |
Georgia Power | ||
Short-term Debt [Line Items] | ||
Amount Outstanding | $ 60 | $ 365 |
Weighted Average Interest Rate | 0.30% | 2.20% |
Georgia Power | Commercial paper | ||
Short-term Debt [Line Items] | ||
Amount Outstanding | $ 60 | $ 115 |
Weighted Average Interest Rate | 0.30% | 2.10% |
Georgia Power | Short-term bank debt | ||
Short-term Debt [Line Items] | ||
Amount Outstanding | $ 0 | $ 250 |
Weighted Average Interest Rate | 0.00% | 2.20% |
Mississippi Power | ||
Short-term Debt [Line Items] | ||
Amount Outstanding | $ 25 | $ 0 |
Mississippi Power | Commercial paper | ||
Short-term Debt [Line Items] | ||
Amount Outstanding | $ 25 | $ 0 |
Weighted Average Interest Rate | 0.40% | 0.00% |
Southern Power | ||
Short-term Debt [Line Items] | ||
Amount Outstanding | $ 175 | $ 549 |
Weighted Average Interest Rate | 0.30% | 2.20% |
Southern Power | Commercial paper | ||
Short-term Debt [Line Items] | ||
Amount Outstanding | $ 175 | $ 449 |
Weighted Average Interest Rate | 0.30% | 2.10% |
Southern Power | Short-term bank debt | ||
Short-term Debt [Line Items] | ||
Amount Outstanding | $ 0 | $ 100 |
Weighted Average Interest Rate | 0.00% | 2.60% |
Southern Company Gas | ||
Short-term Debt [Line Items] | ||
Amount Outstanding | $ 324 | $ 650 |
Southern Company Gas | Commercial paper | ||
Short-term Debt [Line Items] | ||
Amount Outstanding | $ 324 | $ 650 |
Weighted Average Interest Rate | 0.20% | 2.00% |
Southern Company Gas Capital | Commercial paper | ||
Short-term Debt [Line Items] | ||
Amount Outstanding | $ 220 | $ 372 |
Weighted Average Interest Rate | 0.30% | 2.10% |
Nicor Gas | Commercial paper | ||
Short-term Debt [Line Items] | ||
Amount Outstanding | $ 104 | $ 278 |
Weighted Average Interest Rate | 0.20% | 1.80% |
FINANCING - Outstanding Classes
FINANCING - Outstanding Classes of Capital Stock Narrative (Details) - USD ($) shares in Millions, $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Debt Instrument [Line Items] | |||
Stock issued employee and director stock plans (in shares) | 3.3 | ||
Proceeds from issuance of shares under share-based compensation plans | $ 74 | ||
Number of shares reserved for issuance to stock-based compensation plan (in shares) | 88 | ||
Payments for redemption of all outstanding shares of redeemable preferred stock | $ 0 | $ 0 | $ 33 |
Southern Company Common Stock | |||
Debt Instrument [Line Items] | |||
Remaining shares available for awards (in shares) | 6.8 | ||
Mississippi Power | |||
Debt Instrument [Line Items] | |||
Payments for redemption of all outstanding shares of redeemable preferred stock | $ 0 | $ 0 | $ 33 |
FINANCING - Diluted Earnings Pe
FINANCING - Diluted Earnings Per Share (Details) - shares shares in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Debt Disclosure [Abstract] | |||
As reported shares | 1,058 | 1,046 | 1,020 |
Effect of stock-based compensation | 7 | 8 | 5 |
Diluted shares | 1,065 | 1,054 | 1,025 |
FINANCING - Preferred Stock Red
FINANCING - Preferred Stock Redemption (Details) - Alabama Power | 12 Months Ended | |
Dec. 31, 2020$ / sharesshares | Sep. 30, 2022$ / shares | |
4.92% Preferred Stock | ||
Debt Instrument, Redemption [Line Items] | ||
Dividend rate percentage | 0.0492 | |
Par Value/Stated Capital Per Share (in dollars per share) | $ 100 | |
Shares outstanding (in shares) | shares | 80,000 | |
Redemption Price Per Share (in dollars per share) | $ 103.23 | |
4.72% Preferred Stock | ||
Debt Instrument, Redemption [Line Items] | ||
Dividend rate percentage | 0.0472 | |
Par Value/Stated Capital Per Share (in dollars per share) | $ 100 | |
Shares outstanding (in shares) | shares | 50,000 | |
Redemption Price Per Share (in dollars per share) | $ 102.18 | |
4.64% Preferred Stock | ||
Debt Instrument, Redemption [Line Items] | ||
Dividend rate percentage | 0.0464 | |
Par Value/Stated Capital Per Share (in dollars per share) | $ 100 | |
Shares outstanding (in shares) | shares | 60,000 | |
Redemption Price Per Share (in dollars per share) | $ 103.14 | |
4.60% Preferred Stock | ||
Debt Instrument, Redemption [Line Items] | ||
Dividend rate percentage | 0.0460 | |
Par Value/Stated Capital Per Share (in dollars per share) | $ 100 | |
Shares outstanding (in shares) | shares | 100,000 | |
Redemption Price Per Share (in dollars per share) | $ 104.20 | |
4.52% Preferred Stock | ||
Debt Instrument, Redemption [Line Items] | ||
Dividend rate percentage | 0.0452 | |
Par Value/Stated Capital Per Share (in dollars per share) | $ 100 | |
Shares outstanding (in shares) | shares | 50,000 | |
Redemption Price Per Share (in dollars per share) | $ 102.93 | |
4.20% Preferred Stock | ||
Debt Instrument, Redemption [Line Items] | ||
Dividend rate percentage | 0.0420 | |
Par Value/Stated Capital Per Share (in dollars per share) | $ 100 | |
Shares outstanding (in shares) | shares | 135,115 | |
Redemption Price Per Share (in dollars per share) | $ 105 | |
5.00% Class A Preferred Stock | ||
Debt Instrument, Redemption [Line Items] | ||
Dividend rate percentage | 0.0500 | |
Par Value/Stated Capital Per Share (in dollars per share) | $ 25 | |
Shares outstanding (in shares) | shares | 10,000,000 | |
Redemption Price Per Share (in dollars per share) | $ 25 | |
5.00% Class A Preferred Stock | Scenario, Forecast | ||
Debt Instrument, Redemption [Line Items] | ||
Redemption Price Per Share (in dollars per share) | $ 25.50 |
FINANCING - Dividend Restrictio
FINANCING - Dividend Restrictions and Structural Considerations Narrative (Details) $ in Millions | 12 Months Ended |
Dec. 31, 2020USD ($) | |
Variable Interest Entity [Line Items] | |
Undistributed retained earnings of subsidiaries | $ 5,600 |
Southern Company Gas | |
Variable Interest Entity [Line Items] | |
Retained earnings, unappropriated | $ 1,100 |
Southern Company Gas | Southern Company Gas Capital | |
Variable Interest Entity [Line Items] | |
Noncontrolling ownership percentage held by parent | 100.00% |
LEASES - Major Categories of Le
LEASES - Major Categories of Lease Obligations (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Lessee, Lease, Description [Line Items] | ||
Lease obligations | $ 2,083 | $ 2,070 |
Alabama Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 175 | 160 |
Georgia Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 1,452 | 1,582 |
Mississippi Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 28 | 6 |
Southern Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 451 | 398 |
Southern Company Gas | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 82 | 92 |
Electric generating units | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 941 | 990 |
Electric generating units | Alabama Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 146 | 125 |
Electric generating units | Georgia Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 1,368 | 1,487 |
Electric generating units | Mississippi Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 0 | 0 |
Electric generating units | Southern Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 0 | 0 |
Electric generating units | Southern Company Gas | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 0 | 0 |
Real estate/land | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 815 | 782 |
Real estate/land | Alabama Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 4 | 4 |
Real estate/land | Georgia Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 53 | 54 |
Real estate/land | Mississippi Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 2 | 2 |
Real estate/land | Southern Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 451 | 398 |
Real estate/land | Southern Company Gas | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 61 | 74 |
Communication towers | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 158 | 154 |
Communication towers | Alabama Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 2 | 2 |
Communication towers | Georgia Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 3 | 3 |
Communication towers | Mississippi Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 0 | 0 |
Communication towers | Southern Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 0 | 0 |
Communication towers | Southern Company Gas | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 20 | 18 |
Railcars | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 42 | 51 |
Railcars | Alabama Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 16 | 21 |
Railcars | Georgia Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 23 | 26 |
Railcars | Mississippi Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 3 | 3 |
Railcars | Southern Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 0 | 0 |
Railcars | Southern Company Gas | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 0 | 0 |
Other | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 127 | 93 |
Other | Alabama Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 7 | 8 |
Other | Georgia Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 5 | 12 |
Other | Mississippi Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 23 | 1 |
Other | Southern Power | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | 0 | 0 |
Other | Southern Company Gas | ||
Lessee, Lease, Description [Line Items] | ||
Lease obligations | $ 1 | $ 0 |
LEASES - Narrative (Details)
LEASES - Narrative (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2020 | Dec. 31, 2019 | |
Lessee, Lease, Description [Line Items] | |||
Operating lease obligations | $ 1,852 | $ 1,852 | $ 1,844 |
Maximum | Real estate | |||
Lessee, Lease, Description [Line Items] | |||
Remaining terms | 24 years | ||
Maximum | Land | |||
Lessee, Lease, Description [Line Items] | |||
Lessee, lease term | 46 years | ||
Maximum | Communication towers | |||
Lessee, Lease, Description [Line Items] | |||
Lessee, lease term | 10 years | ||
Lessee, renewal period | 20 years | ||
Maximum | Fuel cells | |||
Lessee, Lease, Description [Line Items] | |||
Lessor, lease term, operating lease | 14 years | 14 years | |
Alabama Power | |||
Lessee, Lease, Description [Line Items] | |||
Operating lease obligations | $ 170 | $ 170 | 156 |
Alabama Power | Maximum | Electric generating units | |||
Lessee, Lease, Description [Line Items] | |||
Operating lease remaining lease term | 17 years | 17 years | |
Alabama Power | Minimum | Electric generating units | |||
Lessee, Lease, Description [Line Items] | |||
Operating lease remaining lease term | 3 years | 3 years | |
Georgia Power | |||
Lessee, Lease, Description [Line Items] | |||
Operating lease obligations | $ 1,307 | $ 1,307 | 1,426 |
Variable lease, payment | 39 | 42 | |
Georgia Power | Purchased power, affiliates | |||
Lessee, Lease, Description [Line Items] | |||
Variable lease, payment | 20 | 20 | |
Southern Power | |||
Lessee, Lease, Description [Line Items] | |||
Operating lease obligations | $ 451 | $ 451 | 398 |
Southern Power | Maximum | Electric generating units | |||
Lessee, Lease, Description [Line Items] | |||
Lessor, lease term, operating lease | 26 years | 26 years | |
Mississippi Power | |||
Lessee, Lease, Description [Line Items] | |||
Operating lease obligations | $ 9 | $ 9 | 6 |
Transfer of construction work in progress to lease receivables | 26 | ||
Sales-type lease, lease receivable | 26 | 26 | |
Mississippi Power | Other Property and Investments | |||
Lessee, Lease, Description [Line Items] | |||
Sales-type lease, lease receivable | 24 | 24 | |
Mississippi Power | Other Accounts, Notes, and Loans Receivable | |||
Lessee, Lease, Description [Line Items] | |||
Sales-type lease, lease receivable | $ 2 | $ 2 | |
Mississippi Power | Maximum | Electric generating units | |||
Lessee, Lease, Description [Line Items] | |||
Lessor, lease term, sales-type lease | 18 years | 18 years | |
Southern Company Gas | |||
Lessee, Lease, Description [Line Items] | |||
Operating lease obligations | $ 82 | $ 82 | 92 |
Southern Company Gas | Maximum | |||
Lessee, Lease, Description [Line Items] | |||
Lessor, remaining term | 22 years | ||
Affiliate | Georgia Power | Electric generating units | |||
Lessee, Lease, Description [Line Items] | |||
Operating lease obligations | $ 575 | $ 575 | $ 624 |
Traditional Electric Operating Companies | Maximum | Outdoor lighting | |||
Lessee, Lease, Description [Line Items] | |||
Lessor, lease term, operating lease | 7 years | 7 years |
LEASES - Balance Sheet Amounts
LEASES - Balance Sheet Amounts Recorded for Operating and Financing Leases (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Operating Leases | ||
Operating lease ROU assets, net | $ 1,802 | $ 1,800 |
Operating lease obligations - current | 241 | 229 |
Operating lease obligations - non-current | 1,611 | 1,615 |
Total operating lease obligations | $ 1,852 | $ 1,844 |
Finance Leases | ||
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List] | so:PlantInServiceNetOfDepreciation | so:PlantInServiceNetOfDepreciation |
Finance lease ROU assets, net | $ 218 | $ 216 |
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List] | us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent | us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent |
Finance lease obligations - current | $ 17 | $ 21 |
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List] | us-gaap:LongTermDebtAndCapitalLeaseObligations | us-gaap:LongTermDebtAndCapitalLeaseObligations |
Finance lease obligations - non-current | $ 214 | $ 205 |
Total finance lease obligations | 231 | 226 |
Alabama Power | ||
Operating Leases | ||
Operating lease ROU assets, net | $ 151 | $ 132 |
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] | us-gaap:OtherLiabilitiesCurrent | us-gaap:OtherLiabilitiesCurrent |
Operating lease obligations - current | $ 51 | $ 49 |
Operating lease obligations - non-current | 119 | 107 |
Total operating lease obligations | $ 170 | $ 156 |
Finance Leases | ||
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List] | so:PlantInServiceNetOfDepreciation | so:PlantInServiceNetOfDepreciation |
Finance lease ROU assets, net | $ 5 | $ 4 |
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List] | us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent | us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent |
Finance lease obligations - current | $ 1 | $ 1 |
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List] | us-gaap:LongTermDebtAndCapitalLeaseObligations | us-gaap:LongTermDebtAndCapitalLeaseObligations |
Finance lease obligations - non-current | $ 4 | $ 3 |
Total finance lease obligations | 5 | 4 |
Georgia Power | ||
Operating Leases | ||
Operating lease ROU assets, net | 1,308 | 1,428 |
Operating lease obligations - current | 151 | 144 |
Operating lease obligations - non-current | 1,156 | 1,282 |
Total operating lease obligations | $ 1,307 | $ 1,426 |
Finance Leases | ||
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List] | so:PlantInServiceNetOfDepreciation | so:PlantInServiceNetOfDepreciation |
Finance lease ROU assets, net | $ 115 | $ 130 |
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List] | us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent | us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent |
Finance lease obligations - current | $ 9 | $ 11 |
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List] | us-gaap:LongTermDebtAndCapitalLeaseObligations | us-gaap:LongTermDebtAndCapitalLeaseObligations |
Finance lease obligations - non-current | $ 136 | $ 145 |
Total finance lease obligations | $ 145 | $ 156 |
Mississippi Power | ||
Operating Leases | ||
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List] | us-gaap:OtherAssetsNoncurrent | us-gaap:OtherAssetsNoncurrent |
Operating lease ROU assets, net | $ 9 | $ 6 |
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] | us-gaap:OtherLiabilitiesCurrent | us-gaap:OtherLiabilitiesCurrent |
Operating lease obligations - current | $ 2 | $ 2 |
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List] | us-gaap:OtherLiabilitiesNoncurrent | us-gaap:OtherLiabilitiesNoncurrent |
Operating lease obligations - non-current | $ 7 | $ 4 |
Total operating lease obligations | $ 9 | 6 |
Finance Leases | ||
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List] | so:PlantInServiceNetOfDepreciation | |
Finance lease ROU assets, net | $ 19 | 0 |
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List] | us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent | |
Finance lease obligations - current | $ 1 | 0 |
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List] | us-gaap:LongTermDebtAndCapitalLeaseObligations | |
Finance lease obligations - non-current | $ 18 | 0 |
Total finance lease obligations | 19 | 0 |
Southern Power | ||
Operating Leases | ||
Operating lease ROU assets, net | $ 415 | $ 369 |
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] | us-gaap:OtherLiabilitiesCurrent | us-gaap:OtherLiabilitiesCurrent |
Operating lease obligations - current | $ 25 | $ 22 |
Operating lease obligations - non-current | 426 | 376 |
Total operating lease obligations | 451 | 398 |
Finance Leases | ||
Finance lease ROU assets, net | 0 | 0 |
Finance lease obligations - current | 0 | 0 |
Finance lease obligations - non-current | 0 | 0 |
Total finance lease obligations | 0 | 0 |
Southern Company Gas | ||
Operating Leases | ||
Operating lease ROU assets, net | $ 81 | $ 93 |
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] | us-gaap:OtherLiabilitiesCurrent | us-gaap:OtherLiabilitiesCurrent |
Operating lease obligations - current | $ 15 | $ 14 |
Operating lease obligations - non-current | 67 | 78 |
Total operating lease obligations | 82 | 92 |
Finance Leases | ||
Finance lease ROU assets, net | 0 | 0 |
Finance lease obligations - current | 0 | 0 |
Finance lease obligations - non-current | 0 | 0 |
Total finance lease obligations | $ 0 | $ 0 |
LEASES - Lease Costs (Details)
LEASES - Lease Costs (Details) - USD ($) $ in Millions | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Lease cost | ||
Operating lease cost | $ 309 | $ 310 |
Finance lease cost: | ||
Amortization of ROU assets | 26 | 28 |
Interest on lease obligations | 11 | 12 |
Total finance lease cost | 37 | 40 |
Short-term lease costs | 39 | 48 |
Variable lease cost | 91 | 105 |
Sublease income | 0 | 0 |
Total lease cost | 476 | 503 |
Alabama Power | ||
Lease cost | ||
Operating lease cost | 55 | 54 |
Finance lease cost: | ||
Amortization of ROU assets | 1 | 1 |
Interest on lease obligations | 0 | 0 |
Total finance lease cost | 1 | 1 |
Short-term lease costs | 11 | 19 |
Variable lease cost | 4 | 6 |
Sublease income | (1) | (1) |
Total lease cost | 70 | 79 |
Georgia Power | ||
Lease cost | ||
Operating lease cost | 212 | 206 |
Finance lease cost: | ||
Amortization of ROU assets | 15 | 15 |
Interest on lease obligations | 16 | 18 |
Total finance lease cost | 31 | 33 |
Short-term lease costs | 26 | 22 |
Variable lease cost | 76 | 85 |
Sublease income | 0 | 0 |
Total lease cost | 345 | 346 |
Mississippi Power | ||
Lease cost | ||
Operating lease cost | 3 | 3 |
Finance lease cost: | ||
Amortization of ROU assets | 0 | 0 |
Interest on lease obligations | 0 | 0 |
Total finance lease cost | 0 | 0 |
Short-term lease costs | 0 | 0 |
Variable lease cost | 0 | 0 |
Sublease income | 0 | 0 |
Total lease cost | 3 | 3 |
Southern Power | ||
Lease cost | ||
Operating lease cost | 29 | 28 |
Finance lease cost: | ||
Amortization of ROU assets | 0 | 0 |
Interest on lease obligations | 0 | 0 |
Total finance lease cost | 0 | 0 |
Short-term lease costs | 0 | 0 |
Variable lease cost | 7 | 7 |
Sublease income | 0 | 0 |
Total lease cost | 36 | 35 |
Southern Company Gas | ||
Lease cost | ||
Operating lease cost | 19 | 18 |
Finance lease cost: | ||
Amortization of ROU assets | 0 | 0 |
Interest on lease obligations | 0 | 0 |
Total finance lease cost | 0 | 0 |
Short-term lease costs | 0 | 0 |
Variable lease cost | 0 | 0 |
Sublease income | 0 | 0 |
Total lease cost | $ 19 | $ 18 |
LEASES - Rent Expense and PPA C
LEASES - Rent Expense and PPA Capacity Expense Related to Leases (Details) $ in Millions | 12 Months Ended |
Dec. 31, 2018USD ($) | |
Lessee, Lease, Description [Line Items] | |
Rent expense | $ 192 |
PPA capacity expense | 231 |
Alabama Power | |
Lessee, Lease, Description [Line Items] | |
Rent expense | 23 |
PPA capacity expense | 44 |
Georgia Power | |
Lessee, Lease, Description [Line Items] | |
Rent expense | 34 |
PPA capacity expense | 206 |
Operating leases, contingent rent expense | 72 |
Mississippi Power | |
Lessee, Lease, Description [Line Items] | |
Rent expense | 4 |
PPA capacity expense | 0 |
Operating leases, contingent rent expense | 10 |
Southern Power | |
Lessee, Lease, Description [Line Items] | |
Rent expense | 31 |
PPA capacity expense | 0 |
Southern Company Gas | |
Lessee, Lease, Description [Line Items] | |
Rent expense | 15 |
PPA capacity expense | 0 |
Affiliate Operating Lease PPA | Georgia Power | |
Lessee, Lease, Description [Line Items] | |
Operating leases, contingent rent expense | $ 29 |
LEASES - Other Information (Det
LEASES - Other Information (Details) - USD ($) $ in Millions | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Cash paid for amounts included in the measurements of lease obligations: | ||
Operating cash flows from operating leases | $ 310 | $ 323 |
Operating cash flows from finance leases | 9 | 10 |
Financing cash flows from finance leases | 22 | 32 |
ROU assets obtained in exchange for new operating lease obligations | 227 | 118 |
ROU assets obtained in exchange for new finance lease obligations | $ 10 | $ 35 |
Weighted-average remaining lease term in years: | ||
Operating leases | 14 years 6 months | 14 years 2 months 12 days |
Finance leases | 18 years 2 months 12 days | 18 years 9 months 18 days |
Weighted-average discount rate: | ||
Operating leases | 4.44% | 4.53% |
Finance leases | 4.79% | 5.04% |
Alabama Power | ||
Cash paid for amounts included in the measurements of lease obligations: | ||
Operating cash flows from operating leases | $ 55 | $ 54 |
Operating cash flows from finance leases | 0 | 0 |
Financing cash flows from finance leases | 1 | 1 |
ROU assets obtained in exchange for new operating lease obligations | 63 | 7 |
ROU assets obtained in exchange for new finance lease obligations | $ 2 | $ 2 |
Weighted-average remaining lease term in years: | ||
Operating leases | 7 years 9 months 18 days | 3 years 1 month 6 days |
Finance leases | 9 years 8 months 12 days | 12 years 1 month 6 days |
Weighted-average discount rate: | ||
Operating leases | 4.14% | 3.33% |
Finance leases | 3.20% | 3.60% |
Georgia Power | ||
Cash paid for amounts included in the measurements of lease obligations: | ||
Operating cash flows from operating leases | $ 215 | $ 210 |
Operating cash flows from finance leases | 18 | 19 |
Financing cash flows from finance leases | 11 | 13 |
ROU assets obtained in exchange for new operating lease obligations | 32 | 21 |
ROU assets obtained in exchange for new finance lease obligations | $ 0 | $ 24 |
Weighted-average remaining lease term in years: | ||
Operating leases | 9 years 4 months 24 days | 10 years 2 months 12 days |
Finance leases | 9 years 6 months | 10 years 6 months |
Weighted-average discount rate: | ||
Operating leases | 4.37% | 4.46% |
Finance leases | 10.81% | 10.76% |
Mississippi Power | ||
Cash paid for amounts included in the measurements of lease obligations: | ||
Operating cash flows from operating leases | $ 3 | $ 3 |
Operating cash flows from finance leases | 0 | 0 |
Financing cash flows from finance leases | 0 | 0 |
ROU assets obtained in exchange for new operating lease obligations | 0 | 0 |
ROU assets obtained in exchange for new finance lease obligations | $ 0 | $ 0 |
Weighted-average remaining lease term in years: | ||
Operating leases | 6 years 6 months | 7 years |
Finance leases | 14 years 10 months 24 days | |
Weighted-average discount rate: | ||
Operating leases | 3.26% | 4.02% |
Finance leases | 2.74% | |
Southern Power | ||
Cash paid for amounts included in the measurements of lease obligations: | ||
Operating cash flows from operating leases | $ 28 | $ 27 |
Operating cash flows from finance leases | 0 | 0 |
Financing cash flows from finance leases | 0 | 0 |
ROU assets obtained in exchange for new operating lease obligations | 51 | 2 |
ROU assets obtained in exchange for new finance lease obligations | $ 0 | $ 0 |
Weighted-average remaining lease term in years: | ||
Operating leases | 32 years 1 month 6 days | 32 years 9 months 18 days |
Weighted-average discount rate: | ||
Operating leases | 5.45% | 5.66% |
Southern Company Gas | ||
Cash paid for amounts included in the measurements of lease obligations: | ||
Operating cash flows from operating leases | $ 18 | $ 18 |
Operating cash flows from finance leases | 0 | 0 |
Financing cash flows from finance leases | 0 | 0 |
ROU assets obtained in exchange for new operating lease obligations | 4 | 19 |
ROU assets obtained in exchange for new finance lease obligations | $ 0 | $ 0 |
Weighted-average remaining lease term in years: | ||
Operating leases | 9 years 9 months 18 days | 9 years 10 months 24 days |
Weighted-average discount rate: | ||
Operating leases | 3.67% | 3.70% |
LEASES - Maturities of Lease Li
LEASES - Maturities of Lease Liabilities (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Operating leases: | ||
2021 | $ 300 | |
2022 | 287 | |
2023 | 230 | |
2024 | 187 | |
2025 | 165 | |
Thereafter | 1,546 | |
Total | 2,715 | |
Less: Present value discount | 863 | |
Operating lease obligations, including held for sale | 1,852 | |
Operating lease obligations | 1,852 | $ 1,844 |
Finance leases: | ||
2021 | 28 | |
2022 | 25 | |
2023 | 22 | |
2024 | 19 | |
2025 | 16 | |
Thereafter | 246 | |
Total | 356 | |
Less: Present value discount | 125 | |
Finance lease obligations | 231 | 226 |
Alabama Power | ||
Operating leases: | ||
2021 | 57 | |
2022 | 58 | |
2023 | 9 | |
2024 | 6 | |
2025 | 6 | |
Thereafter | 74 | |
Total | 210 | |
Less: Present value discount | 40 | |
Operating lease obligations | 170 | 156 |
Finance leases: | ||
2021 | 1 | |
2022 | 1 | |
2023 | 1 | |
2024 | 1 | |
2025 | 0 | |
Thereafter | 1 | |
Total | 5 | |
Less: Present value discount | 0 | |
Finance lease obligations | 5 | 4 |
Georgia Power | ||
Operating leases: | ||
2021 | 205 | |
2022 | 202 | |
2023 | 200 | |
2024 | 164 | |
2025 | 137 | |
Thereafter | 701 | |
Total | 1,609 | |
Less: Present value discount | 302 | |
Operating lease obligations | 1,307 | 1,426 |
Finance leases: | ||
2021 | 24 | |
2022 | 25 | |
2023 | 25 | |
2024 | 25 | |
2025 | 25 | |
Thereafter | 109 | |
Total | 233 | |
Less: Present value discount | 88 | |
Finance lease obligations | 145 | 156 |
Mississippi Power | ||
Operating leases: | ||
2021 | 2 | |
2022 | 4 | |
2023 | 1 | |
2024 | 1 | |
2025 | 0 | |
Thereafter | 2 | |
Total | 10 | |
Less: Present value discount | 1 | |
Operating lease obligations | 9 | 6 |
Finance leases: | ||
2021 | 2 | |
2022 | 1 | |
2023 | 2 | |
2024 | 1 | |
2025 | 2 | |
Thereafter | 15 | |
Total | 23 | |
Less: Present value discount | 4 | |
Finance lease obligations | 19 | 0 |
Southern Power | ||
Operating leases: | ||
2021 | 30 | |
2022 | 25 | |
2023 | 27 | |
2024 | 27 | |
2025 | 27 | |
Thereafter | 873 | |
Total | 1,009 | |
Less: Present value discount | 558 | |
Operating lease obligations | 451 | 398 |
Finance leases: | ||
2021 | 0 | |
2022 | 0 | |
2023 | 0 | |
2024 | 0 | |
2025 | 0 | |
Thereafter | 0 | |
Total | 0 | |
Less: Present value discount | 0 | |
Finance lease obligations | 0 | 0 |
Southern Company Gas | ||
Operating leases: | ||
2021 | 18 | |
2022 | 14 | |
2023 | 12 | |
2024 | 11 | |
2025 | 10 | |
Thereafter | 35 | |
Total | 100 | |
Less: Present value discount | 18 | |
Operating lease obligations | 82 | 92 |
Finance leases: | ||
2021 | 0 | |
2022 | 0 | |
2023 | 0 | |
2024 | 0 | |
2025 | 0 | |
Thereafter | 0 | |
Total | 0 | |
Less: Present value discount | 0 | |
Finance lease obligations | $ 0 | $ 0 |
LEASES - Leases Not Yet Commenc
LEASES - Leases Not Yet Commenced (Details) - Southern Power $ in Millions | Dec. 31, 2020USD ($) |
Lessee, Lease, Description [Line Items] | |
Estimated total obligations | $ 12 |
Maximum | |
Lessee, Lease, Description [Line Items] | |
Longest lease term expiration | 30 years |
LEASES - Lease Income (Details)
LEASES - Lease Income (Details) - USD ($) $ in Millions | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Lessor, Lease, Description [Line Items] | ||
Lease income - interest income on sales-type leases | $ 16 | $ 9 |
Lease income - operating leases | 208 | 273 |
Variable lease income | 419 | 403 |
Total lease income | 643 | 685 |
Alabama Power | ||
Lessor, Lease, Description [Line Items] | ||
Lease income - interest income on sales-type leases | 0 | 0 |
Lease income - operating leases | 45 | 24 |
Variable lease income | 0 | 0 |
Total lease income | 45 | 24 |
Georgia Power | ||
Lessor, Lease, Description [Line Items] | ||
Lease income - interest income on sales-type leases | 0 | 0 |
Lease income - operating leases | 58 | 71 |
Variable lease income | 0 | 0 |
Total lease income | 58 | 71 |
Mississippi Power | ||
Lessor, Lease, Description [Line Items] | ||
Lease income - interest income on sales-type leases | 12 | 9 |
Lease income - operating leases | 2 | 0 |
Variable lease income | 0 | 0 |
Total lease income | 14 | 9 |
Southern Power | ||
Lessor, Lease, Description [Line Items] | ||
Lease income - interest income on sales-type leases | 0 | 0 |
Lease income - operating leases | 87 | 160 |
Variable lease income | 449 | 434 |
Total lease income | 536 | 594 |
Southern Company Gas | ||
Lessor, Lease, Description [Line Items] | ||
Lease income - interest income on sales-type leases | 0 | 0 |
Lease income - operating leases | 35 | 35 |
Variable lease income | 0 | 0 |
Total lease income | $ 35 | $ 35 |
LEASES - Undiscounted Cash Flow
LEASES - Undiscounted Cash Flows to be Received Under Tolling Arrangements Accounted for as Sales-type Leases (Details) - Mississippi Power $ in Millions | Dec. 31, 2020USD ($) |
Sales-type and Direct Financing Leases, Lease Receivable, Fiscal Year Maturity [Abstract] | |
2021 | $ 20 |
2022 | 19 |
2023 | 19 |
2024 | 18 |
2025 | 17 |
Thereafter | 162 |
Total undiscounted cash flows | 255 |
Lease receivable | 138 |
Difference between undiscounted cash flows and discounted cash flows | $ 117 |
LEASES - Undiscounted Cash Fl_2
LEASES - Undiscounted Cash Flows to be Received Under PPAs Accounted for as Operating Leases (Details) $ in Millions | Dec. 31, 2020USD ($) |
Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract] | |
2021 | $ 207 |
2022 | 187 |
2023 | 138 |
2024 | 106 |
2025 | 99 |
Thereafter | 978 |
Total | 1,715 |
Alabama Power | |
Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract] | |
2021 | 83 |
2022 | 76 |
2023 | 32 |
2024 | 4 |
2025 | 3 |
Thereafter | 23 |
Total | 221 |
Georgia Power | |
Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract] | |
2021 | 19 |
2022 | 8 |
2023 | 2 |
2024 | 0 |
2025 | 0 |
Thereafter | 0 |
Total | 29 |
Southern Power | |
Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract] | |
2021 | 86 |
2022 | 87 |
2023 | 88 |
2024 | 90 |
2025 | 74 |
Thereafter | 313 |
Total | 738 |
Southern Company Gas | |
Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract] | |
2021 | 35 |
2022 | 35 |
2023 | 34 |
2024 | 33 |
2025 | 28 |
Thereafter | 435 |
Total | $ 600 |
INCOME TAXES - Current and Defe
INCOME TAXES - Current and Deferred Income Tax Provisions (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Federal — | |||
Current | $ 199 | $ 156 | $ 167 |
Deferred | 70 | 1,237 | 231 |
Total federal taxes | 269 | 1,393 | 398 |
State — | |||
Current | 100 | 275 | 188 |
Deferred | 24 | 130 | (137) |
Total state taxes | 124 | 405 | 51 |
Income taxes | 393 | 1,798 | 449 |
Alabama Power | |||
Federal — | |||
Current | 198 | 61 | 91 |
Deferred | 44 | 125 | 123 |
Total federal taxes | 242 | 186 | 214 |
State — | |||
Current | 61 | 12 | 26 |
Deferred | 34 | 72 | 51 |
Total state taxes | 95 | 84 | 77 |
Income taxes | 337 | 270 | 291 |
Georgia Power | |||
Federal — | |||
Current | 365 | 264 | 393 |
Deferred | (224) | 180 | (249) |
Total federal taxes | 141 | 444 | 144 |
State — | |||
Current | 60 | 6 | 81 |
Deferred | (49) | 22 | (11) |
Total state taxes | 11 | 28 | 70 |
Income taxes | 152 | 472 | 214 |
Mississippi Power | |||
Federal — | |||
Current | 18 | (6) | (567) |
Deferred | (14) | 26 | 575 |
Total federal taxes | 4 | 20 | 8 |
State — | |||
Current | 0 | (1) | (10) |
Deferred | 10 | 11 | (100) |
Total state taxes | 10 | 10 | (110) |
Income taxes | 14 | 30 | (102) |
Southern Power | |||
Federal — | |||
Current | (303) | (717) | 85 |
Deferred | 299 | 647 | (154) |
Total federal taxes | (4) | (70) | (69) |
State — | |||
Current | (4) | 1 | (9) |
Deferred | 11 | 13 | (86) |
Total state taxes | 7 | 14 | (95) |
Income taxes | 3 | (56) | (164) |
Southern Company Gas | |||
Federal — | |||
Current | 82 | (120) | 334 |
Deferred | 53 | 195 | 33 |
Total federal taxes | 135 | 75 | 367 |
State — | |||
Current | 35 | 37 | 131 |
Deferred | 3 | 18 | (34) |
Total state taxes | 38 | 55 | 97 |
Income taxes | $ 173 | $ 130 | $ 464 |
INCOME TAXES - Narrative (Detai
INCOME TAXES - Narrative (Details) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020USD ($) | Dec. 31, 2019USD ($) | Dec. 31, 2018USD ($)operating_facility | |
Income Tax Disclosure [Line Items] | |||
Deferred income tax assets | $ 8,874 | $ 8,680 | |
Income tax benefit | (393) | (1,798) | $ (449) |
ITC and PTC carryforward | |||
Income Tax Disclosure [Line Items] | |||
Deferred income tax assets | 1,853 | 2,098 | |
Southern Power | |||
Income Tax Disclosure [Line Items] | |||
Deferred income tax assets | $ 1,587 | 1,917 | |
Percentage reduction in tax basis of assets | 50.00% | ||
Number of wind facilities | operating_facility | 8 | ||
Income tax benefit | $ (3) | 56 | $ 164 |
Southern Power | ITCs and other credits carryforward | |||
Income Tax Disclosure [Line Items] | |||
Reduction in income tax expense, investment tax credits | 340 | 734 | 5 |
Southern Power | ITC and PTC carryforward | |||
Income Tax Disclosure [Line Items] | |||
Deferred income tax assets | 1,110 | 1,445 | |
Southern Power | ITC and PTC carryforward | Nacogdoches Biomass Generating Plant | |||
Income Tax Disclosure [Line Items] | |||
Reduction in income tax expense, investment tax credits | 5 | 1 | |
Southern Power | Production Tax Credit Carryforward | |||
Income Tax Disclosure [Line Items] | |||
Effective income tax rate reconciliation, tax credit, production, amount | 15 | 12 | 141 |
Georgia Power | |||
Income Tax Disclosure [Line Items] | |||
Deferred income tax assets | 3,443 | 3,123 | |
Income tax benefit | (152) | (472) | (214) |
State investment tax credit carryforward | 343 | ||
Georgia Power | ITC and PTC carryforward | |||
Income Tax Disclosure [Line Items] | |||
Deferred income tax assets | 539 | 435 | |
Mississippi Power | |||
Income Tax Disclosure [Line Items] | |||
Deferred income tax assets | 428 | 451 | |
Income tax benefit | (14) | (30) | 102 |
Mississippi Power | ITC and PTC carryforward | |||
Income Tax Disclosure [Line Items] | |||
Deferred income tax assets | 0 | 0 | |
State and Local Jurisdiction | Southern Power | |||
Income Tax Disclosure [Line Items] | |||
Income tax benefit | 65 | ||
State and Local Jurisdiction | Georgia Power | |||
Income Tax Disclosure [Line Items] | |||
Valuation allowance | 28 | ||
State and Local Jurisdiction | Georgia Power | ITCs and other credits carryforward | |||
Income Tax Disclosure [Line Items] | |||
Reduction in income tax expense, investment tax credits | 67 | 51 | 21 |
Deferred Charges Related To Income Taxes, Current | Other Noncurrent Assets | Southern Power | Unrealized Tax Credits | |||
Income Tax Disclosure [Line Items] | |||
Deferred income tax assets | 5 | $ 51 | $ 128 |
Mississippi | State and Local Jurisdiction | Mississippi Power | |||
Income Tax Disclosure [Line Items] | |||
Operating loss carryforwards, valuation allowance | 32 | ||
Oklahoma | State and Local Jurisdiction | Southern Power | |||
Income Tax Disclosure [Line Items] | |||
Operating loss carryforwards, valuation allowance | 16 | ||
Florida | State and Local Jurisdiction | Southern Power | |||
Income Tax Disclosure [Line Items] | |||
Operating loss carryforwards, valuation allowance | $ 11 |
INCOME TAXES - Amortization of
INCOME TAXES - Amortization of Deferred Credits (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Income Tax Disclosure [Line Items] | |||
Amortization of deferred investment tax credits | $ 84 | $ 181 | $ 87 |
Southern Power | |||
Income Tax Disclosure [Line Items] | |||
Amortization of deferred investment tax credits | $ 59 | $ 151 | $ 58 |
INCOME TAXES - Reconciliation o
INCOME TAXES - Reconciliation of Federal Statutory Income Tax Rate (Details) | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Reconciliation of federal statutory income tax rate to effective income tax rate | |||
Federal statutory rate | 21.00% | 21.00% | 21.00% |
State income tax, net of federal deduction | 2.80% | 4.90% | 1.80% |
Employee stock plans' dividend deduction | (0.70%) | (0.40%) | (1.00%) |
Non-deductible book depreciation | 0.70% | 0.30% | 0.80% |
Flowback of excess deferred income taxes | (8.80%) | (2.10%) | (4.00%) |
AFUDC-Equity | (0.80%) | (0.40%) | (1.00%) |
ITC basis difference | (0.10%) | (0.60%) | |
Federal PTCs | 0.00% | (4.70%) | |
Amortization of ITC | (1.60%) | (0.80%) | (2.00%) |
Tax impact from sale of subsidiaries | 5.10% | 8.60% | |
Tax Reform Legislation | (1.40%) | ||
Noncontrolling interests | 0.00% | 0.00% | (0.40%) |
Leveraged lease impairments | (1.60%) | ||
Other | 0.20% | 0.00% | (0.80%) |
Effective income tax (benefit) rate | 11.20% | 27.50% | 16.30% |
Alabama Power | |||
Reconciliation of federal statutory income tax rate to effective income tax rate | |||
Federal statutory rate | 21.00% | 21.00% | 21.00% |
State income tax, net of federal deduction | 5.00% | 4.90% | 5.00% |
Employee stock plans' dividend deduction | 0.00% | 0.00% | 0.00% |
Non-deductible book depreciation | 0.60% | 0.60% | 0.60% |
Flowback of excess deferred income taxes | (3.10%) | (5.30%) | (1.80%) |
AFUDC-Equity | (0.60%) | (0.80%) | (1.00%) |
ITC basis difference | 0.00% | 0.00% | |
Federal PTCs | 0.00% | 0.00% | |
Amortization of ITC | (0.10%) | (0.10%) | (0.10%) |
Tax impact from sale of subsidiaries | 0.00% | 0.00% | |
Tax Reform Legislation | 0.00% | ||
Noncontrolling interests | 0.00% | 0.00% | 0.00% |
Leveraged lease impairments | 0.00% | ||
Other | (0.30%) | (0.40%) | (0.10%) |
Effective income tax (benefit) rate | 22.50% | 19.90% | 23.60% |
Georgia Power | |||
Reconciliation of federal statutory income tax rate to effective income tax rate | |||
Federal statutory rate | 21.00% | 21.00% | 21.00% |
State income tax, net of federal deduction | 0.50% | 1.00% | 5.50% |
Employee stock plans' dividend deduction | 0.00% | 0.00% | 0.00% |
Non-deductible book depreciation | 0.80% | 0.50% | 1.20% |
Flowback of excess deferred income taxes | (12.00%) | 0.00% | 0.00% |
AFUDC-Equity | (1.10%) | (0.60%) | (1.40%) |
ITC basis difference | 0.00% | 0.00% | |
Federal PTCs | 0.00% | 0.00% | |
Amortization of ITC | (0.10%) | (0.10%) | (0.20%) |
Tax impact from sale of subsidiaries | 0.00% | 0.00% | |
Tax Reform Legislation | (4.90%) | ||
Noncontrolling interests | 0.00% | 0.00% | 0.00% |
Leveraged lease impairments | 0.00% | ||
Other | (0.30%) | (0.30%) | 0.10% |
Effective income tax (benefit) rate | 8.80% | 21.50% | 21.30% |
Mississippi Power | |||
Reconciliation of federal statutory income tax rate to effective income tax rate | |||
Federal statutory rate | 21.00% | 21.00% | 21.00% |
State income tax, net of federal deduction | 4.80% | 4.30% | (65.10%) |
Employee stock plans' dividend deduction | 0.00% | 0.00% | 0.00% |
Non-deductible book depreciation | 0.50% | 0.40% | 0.70% |
Flowback of excess deferred income taxes | (18.50%) | (12.60%) | (4.10%) |
AFUDC-Equity | (0.10%) | (0.10%) | 0.00% |
ITC basis difference | 0.00% | 0.00% | |
Federal PTCs | 0.00% | 0.00% | |
Amortization of ITC | (0.10%) | (0.10%) | (0.20%) |
Tax impact from sale of subsidiaries | 0.00% | 0.00% | |
Tax Reform Legislation | (26.30%) | ||
Noncontrolling interests | 0.00% | 0.00% | 0.00% |
Leveraged lease impairments | 0.00% | ||
Other | 0.90% | 4.90% | (1.40%) |
Effective income tax (benefit) rate | 8.50% | 17.80% | (75.40%) |
Southern Power | |||
Reconciliation of federal statutory income tax rate to effective income tax rate | |||
Federal statutory rate | 21.00% | 21.00% | 21.00% |
State income tax, net of federal deduction | 2.70% | 4.00% | (90.80%) |
Employee stock plans' dividend deduction | 0.00% | 0.00% | 0.00% |
Non-deductible book depreciation | 0.00% | 0.00% | 0.00% |
Flowback of excess deferred income taxes | 0.00% | 0.00% | 0.00% |
AFUDC-Equity | 0.00% | 0.00% | 0.00% |
ITC basis difference | (1.90%) | (0.20%) | |
Federal PTCs | (2.50%) | (156.60%) | |
Amortization of ITC | (22.10%) | (16.10%) | (55.40%) |
Tax impact from sale of subsidiaries | (27.60%) | 0.00% | |
Tax Reform Legislation | 96.10% | ||
Noncontrolling interests | 3.10% | 0.80% | (14.90%) |
Leveraged lease impairments | 0.00% | ||
Other | (0.90%) | (0.60%) | 2.00% |
Effective income tax (benefit) rate | 1.30% | (20.40%) | (198.80%) |
Southern Company Gas | |||
Reconciliation of federal statutory income tax rate to effective income tax rate | |||
Federal statutory rate | 21.00% | 21.00% | 21.00% |
State income tax, net of federal deduction | 4.00% | 6.10% | 9.20% |
Employee stock plans' dividend deduction | 0.00% | 0.00% | 0.00% |
Non-deductible book depreciation | 0.00% | 0.00% | 0.00% |
Flowback of excess deferred income taxes | (2.70%) | (6.00%) | (3.00%) |
AFUDC-Equity | 0.00% | 0.00% | 0.00% |
ITC basis difference | 0.00% | 0.00% | |
Federal PTCs | 0.00% | 0.00% | |
Amortization of ITC | (0.10%) | (0.10%) | (0.10%) |
Tax impact from sale of subsidiaries | (1.40%) | 28.50% | |
Tax Reform Legislation | (0.40%) | ||
Noncontrolling interests | 0.00% | 0.00% | 0.00% |
Leveraged lease impairments | 0.00% | ||
Other | 0.50% | (1.40%) | 0.30% |
Effective income tax (benefit) rate | 22.70% | 18.20% | 55.50% |
INCOME TAXES - Deferred Tax Ass
INCOME TAXES - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Deferred tax liabilities — | ||
Deferred income tax liabilities | $ 16,781 | $ 16,261 |
Deferred tax assets — | ||
Deferred income tax assets | 8,874 | 8,680 |
Valuation allowance | (136) | (137) |
Net deferred income tax assets | 8,738 | 8,543 |
Net deferred income taxes liabilities | 8,043 | 7,718 |
Accumulated deferred income taxes – assets | (132) | (170) |
Accumulated deferred income taxes – liabilities | 8,175 | 7,888 |
Accelerated depreciation | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 8,950 | 8,711 |
Property basis differences | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 1,999 | 1,843 |
Federal effect of net state deferred tax assets/liabilities | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Deferred tax assets — | ||
Deferred income tax assets | 284 | 277 |
Leveraged lease basis differences | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 142 | 236 |
Employee benefit obligations | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 739 | 704 |
Deferred tax assets — | ||
Deferred income tax assets | 1,511 | 1,385 |
Premium on reacquired debt | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 78 | 83 |
Storm damage reserves | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 80 | 109 |
Employee benefit obligations | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 1,313 | 1,174 |
Remaining book value of retired assets | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 270 | 341 |
AROs | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 1,969 | 1,723 |
AROs | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 804 | 814 |
Other | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 437 | 523 |
Other property basis differences | ||
Deferred tax assets — | ||
Deferred income tax assets | 223 | 230 |
ITC and PTC carryforward | ||
Deferred tax assets — | ||
Deferred income tax assets | 1,853 | 2,098 |
Long-term debt fair value adjustment | ||
Deferred tax assets — | ||
Deferred income tax assets | 86 | 97 |
Other partnership basis difference | ||
Deferred tax assets — | ||
Deferred income tax assets | 166 | 169 |
Other comprehensive losses | ||
Deferred tax assets — | ||
Deferred income tax assets | 128 | 112 |
AROs | ||
Deferred tax assets — | ||
Deferred income tax assets | 2,773 | 2,537 |
Estimated loss on plants under construction | ||
Deferred tax assets — | ||
Deferred income tax assets | 369 | 283 |
Other deferred state tax attributes | ||
Deferred tax assets — | ||
Deferred income tax assets | 357 | 402 |
Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) | ||
Deferred tax assets — | ||
Deferred income tax assets | 338 | 401 |
Other | ||
Deferred tax assets — | ||
Deferred income tax assets | 660 | 689 |
Alabama Power | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 5,416 | 5,161 |
Deferred tax assets — | ||
Deferred income tax assets | 2,143 | 1,901 |
Valuation allowance | 0 | 0 |
Net deferred income tax assets | 2,143 | 1,901 |
Net deferred income taxes liabilities | 3,273 | 3,260 |
Accumulated deferred income taxes – assets | 0 | 0 |
Accumulated deferred income taxes – liabilities | 3,273 | 3,260 |
Alabama Power | Accelerated depreciation | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 2,453 | 2,402 |
Alabama Power | Property basis differences | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 1,010 | 912 |
Alabama Power | Federal effect of net state deferred tax assets/liabilities | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Deferred tax assets — | ||
Deferred income tax assets | 151 | 162 |
Alabama Power | Leveraged lease basis differences | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Alabama Power | Employee benefit obligations | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 250 | 242 |
Deferred tax assets — | ||
Deferred income tax assets | 369 | 334 |
Alabama Power | Premium on reacquired debt | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 12 | 13 |
Alabama Power | Storm damage reserves | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Alabama Power | Employee benefit obligations | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 348 | 311 |
Alabama Power | Remaining book value of retired assets | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 123 | 174 |
Alabama Power | AROs | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 764 | 613 |
Alabama Power | AROs | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 328 | 360 |
Alabama Power | Other | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 128 | 134 |
Alabama Power | Other property basis differences | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Alabama Power | ITC and PTC carryforward | ||
Deferred tax assets — | ||
Deferred income tax assets | 12 | 11 |
Alabama Power | Long-term debt fair value adjustment | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Alabama Power | Other partnership basis difference | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Alabama Power | Other comprehensive losses | ||
Deferred tax assets — | ||
Deferred income tax assets | 7 | 8 |
Alabama Power | AROs | ||
Deferred tax assets — | ||
Deferred income tax assets | 1,092 | 973 |
Alabama Power | Estimated loss on plants under construction | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Alabama Power | Other deferred state tax attributes | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Alabama Power | Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) | ||
Deferred tax assets — | ||
Deferred income tax assets | 243 | 240 |
Alabama Power | Other | ||
Deferred tax assets — | ||
Deferred income tax assets | 143 | 173 |
Georgia Power | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 6,680 | 6,345 |
Deferred tax assets — | ||
Deferred income tax assets | 3,443 | 3,123 |
Valuation allowance | (35) | (35) |
Net deferred income tax assets | 3,408 | 3,088 |
Net deferred income taxes liabilities | 3,272 | 3,257 |
Accumulated deferred income taxes – assets | 0 | 0 |
Accumulated deferred income taxes – liabilities | 3,272 | 3,257 |
Georgia Power | Accelerated depreciation | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 3,228 | 3,058 |
Georgia Power | Property basis differences | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 689 | 643 |
Georgia Power | Federal effect of net state deferred tax assets/liabilities | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Deferred tax assets — | ||
Deferred income tax assets | 59 | 63 |
Georgia Power | Leveraged lease basis differences | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Georgia Power | Employee benefit obligations | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 362 | 351 |
Deferred tax assets — | ||
Deferred income tax assets | 522 | 488 |
Georgia Power | Premium on reacquired debt | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 66 | 70 |
Georgia Power | Storm damage reserves | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 80 | 109 |
Georgia Power | Employee benefit obligations | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 438 | 403 |
Georgia Power | Remaining book value of retired assets | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 141 | 159 |
Georgia Power | AROs | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 1,165 | 1,066 |
Georgia Power | AROs | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 429 | 405 |
Georgia Power | Other | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 82 | 81 |
Georgia Power | Other property basis differences | ||
Deferred tax assets — | ||
Deferred income tax assets | 72 | 65 |
Georgia Power | ITC and PTC carryforward | ||
Deferred tax assets — | ||
Deferred income tax assets | 539 | 435 |
Georgia Power | Long-term debt fair value adjustment | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Georgia Power | Other partnership basis difference | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Georgia Power | Other comprehensive losses | ||
Deferred tax assets — | ||
Deferred income tax assets | 17 | 18 |
Georgia Power | AROs | ||
Deferred tax assets — | ||
Deferred income tax assets | 1,594 | 1,471 |
Georgia Power | Estimated loss on plants under construction | ||
Deferred tax assets — | ||
Deferred income tax assets | 369 | 283 |
Georgia Power | Other deferred state tax attributes | ||
Deferred tax assets — | ||
Deferred income tax assets | 9 | 13 |
Georgia Power | Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) | ||
Deferred tax assets — | ||
Deferred income tax assets | 76 | 133 |
Georgia Power | Other | ||
Deferred tax assets — | ||
Deferred income tax assets | 186 | 154 |
Mississippi Power | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 705 | 695 |
Deferred tax assets — | ||
Deferred income tax assets | 428 | 451 |
Valuation allowance | (41) | (41) |
Net deferred income tax assets | 387 | 410 |
Net deferred income taxes liabilities | 318 | 285 |
Accumulated deferred income taxes – assets | (129) | (139) |
Accumulated deferred income taxes – liabilities | 447 | 424 |
Mississippi Power | Accelerated depreciation | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 319 | 315 |
Mississippi Power | Property basis differences | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 148 | 143 |
Mississippi Power | Federal effect of net state deferred tax assets/liabilities | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 25 | 24 |
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Mississippi Power | Leveraged lease basis differences | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Mississippi Power | Employee benefit obligations | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 39 | 38 |
Deferred tax assets — | ||
Deferred income tax assets | 80 | 72 |
Mississippi Power | Premium on reacquired debt | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Mississippi Power | Storm damage reserves | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Mississippi Power | Employee benefit obligations | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 62 | 55 |
Mississippi Power | Remaining book value of retired assets | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 6 | 8 |
Mississippi Power | AROs | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 40 | 44 |
Mississippi Power | AROs | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Mississippi Power | Other | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 66 | 68 |
Mississippi Power | Other property basis differences | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Mississippi Power | ITC and PTC carryforward | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Mississippi Power | Long-term debt fair value adjustment | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Mississippi Power | Other partnership basis difference | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Mississippi Power | Other comprehensive losses | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Mississippi Power | AROs | ||
Deferred tax assets — | ||
Deferred income tax assets | 40 | 44 |
Mississippi Power | Estimated loss on plants under construction | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Mississippi Power | Other deferred state tax attributes | ||
Deferred tax assets — | ||
Deferred income tax assets | 250 | 251 |
Mississippi Power | Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) | ||
Deferred tax assets — | ||
Deferred income tax assets | 19 | 28 |
Mississippi Power | Other | ||
Deferred tax assets — | ||
Deferred income tax assets | 39 | 56 |
Southern Power | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 1,413 | 1,445 |
Deferred tax assets — | ||
Deferred income tax assets | 1,587 | 1,917 |
Valuation allowance | (35) | (36) |
Net deferred income tax assets | 1,552 | 1,881 |
Net deferred income taxes assets | (139) | (436) |
Accumulated deferred income taxes – assets | (262) | (551) |
Accumulated deferred income taxes – liabilities | 123 | 115 |
Southern Power | Accelerated depreciation | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 1,389 | 1,422 |
Southern Power | Property basis differences | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Southern Power | Federal effect of net state deferred tax assets/liabilities | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Deferred tax assets — | ||
Deferred income tax assets | 26 | 24 |
Southern Power | Leveraged lease basis differences | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Southern Power | Employee benefit obligations | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 12 | 12 |
Deferred tax assets — | ||
Deferred income tax assets | 6 | 5 |
Southern Power | Premium on reacquired debt | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Southern Power | Storm damage reserves | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Southern Power | Employee benefit obligations | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Southern Power | Remaining book value of retired assets | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Southern Power | AROs | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Southern Power | AROs | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Southern Power | Other | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 12 | 11 |
Southern Power | Other property basis differences | ||
Deferred tax assets — | ||
Deferred income tax assets | 134 | 146 |
Southern Power | ITC and PTC carryforward | ||
Deferred tax assets — | ||
Deferred income tax assets | 1,110 | 1,445 |
Southern Power | Long-term debt fair value adjustment | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Southern Power | Other partnership basis difference | ||
Deferred tax assets — | ||
Deferred income tax assets | 166 | 169 |
Southern Power | Other comprehensive losses | ||
Deferred tax assets — | ||
Deferred income tax assets | 25 | 10 |
Southern Power | AROs | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Southern Power | Estimated loss on plants under construction | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Southern Power | Other deferred state tax attributes | ||
Deferred tax assets — | ||
Deferred income tax assets | 68 | 72 |
Southern Power | Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Southern Power | Other | ||
Deferred tax assets — | ||
Deferred income tax assets | 52 | 46 |
Southern Company Gas | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 1,693 | 1,676 |
Deferred tax assets — | ||
Deferred income tax assets | 432 | 462 |
Valuation allowance | (4) | (5) |
Net deferred income tax assets | 428 | 457 |
Net deferred income taxes liabilities | 1,265 | 1,219 |
Accumulated deferred income taxes – assets | 0 | 0 |
Accumulated deferred income taxes – liabilities | 1,265 | 1,219 |
Southern Company Gas | Accelerated depreciation | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 1,349 | 1,288 |
Southern Company Gas | Property basis differences | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 135 | 133 |
Southern Company Gas | Federal effect of net state deferred tax assets/liabilities | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Deferred tax assets — | ||
Deferred income tax assets | 70 | 56 |
Southern Company Gas | Leveraged lease basis differences | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Southern Company Gas | Employee benefit obligations | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 26 | 12 |
Deferred tax assets — | ||
Deferred income tax assets | 100 | 111 |
Southern Company Gas | Premium on reacquired debt | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Southern Company Gas | Storm damage reserves | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Southern Company Gas | Employee benefit obligations | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 45 | 45 |
Southern Company Gas | Remaining book value of retired assets | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Southern Company Gas | AROs | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Southern Company Gas | AROs | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 0 | 0 |
Southern Company Gas | Other | ||
Deferred tax liabilities — | ||
Deferred income tax liabilities | 138 | 198 |
Southern Company Gas | Other property basis differences | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Southern Company Gas | ITC and PTC carryforward | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Southern Company Gas | Long-term debt fair value adjustment | ||
Deferred tax assets — | ||
Deferred income tax assets | 86 | 97 |
Southern Company Gas | Other partnership basis difference | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Southern Company Gas | Other comprehensive losses | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Southern Company Gas | AROs | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Southern Company Gas | Estimated loss on plants under construction | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Southern Company Gas | Other deferred state tax attributes | ||
Deferred tax assets — | ||
Deferred income tax assets | 10 | 8 |
Southern Company Gas | Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) | ||
Deferred tax assets — | ||
Deferred income tax assets | 0 | 0 |
Southern Company Gas | Other | ||
Deferred tax assets — | ||
Deferred income tax assets | $ 166 | $ 190 |
INCOME TAXES - Federal ITC_PTC
INCOME TAXES - Federal ITC/PTC Carryforwards (Details) - ITC and PTC carryforward $ in Millions | Dec. 31, 2020USD ($) |
Operating Loss Carryforwards [Line Items] | |
Federal ITC/PTC carryforwards | $ 1,428 |
Alabama Power | |
Operating Loss Carryforwards [Line Items] | |
Federal ITC/PTC carryforwards | 12 |
Georgia Power | |
Operating Loss Carryforwards [Line Items] | |
Federal ITC/PTC carryforwards | 114 |
Southern Power | |
Operating Loss Carryforwards [Line Items] | |
Federal ITC/PTC carryforwards | $ 1,110 |
INCOME TAXES - NOL Carryforward
INCOME TAXES - NOL Carryforwards (Details) $ in Millions | Dec. 31, 2020USD ($) |
Operating Loss Carryforwards [Line Items] | |
Approximate Net State Income Tax Benefit of NOL Carryforwards | $ 299 |
Mississippi Power | Mississippi | |
Operating Loss Carryforwards [Line Items] | |
Approximate Net State Income Tax Benefit of NOL Carryforwards | 200 |
Southern Power | |
Operating Loss Carryforwards [Line Items] | |
Approximate Net State Income Tax Benefit of NOL Carryforwards | 53 |
Southern Power | Oklahoma | |
Operating Loss Carryforwards [Line Items] | |
Approximate Net State Income Tax Benefit of NOL Carryforwards | 39 |
Southern Power | Florida | |
Operating Loss Carryforwards [Line Items] | |
Approximate Net State Income Tax Benefit of NOL Carryforwards | 11 |
Southern Power | South Carolina | |
Operating Loss Carryforwards [Line Items] | |
Approximate Net State Income Tax Benefit of NOL Carryforwards | 2 |
Southern Power | Other states | |
Operating Loss Carryforwards [Line Items] | |
Approximate Net State Income Tax Benefit of NOL Carryforwards | 1 |
Other Subsidiaries | Other states | |
Operating Loss Carryforwards [Line Items] | |
Approximate Net State Income Tax Benefit of NOL Carryforwards | 21 |
Other Subsidiaries | New York | |
Operating Loss Carryforwards [Line Items] | |
Approximate Net State Income Tax Benefit of NOL Carryforwards | 11 |
Other Subsidiaries | New York City | |
Operating Loss Carryforwards [Line Items] | |
Approximate Net State Income Tax Benefit of NOL Carryforwards | $ 14 |
INCOME TAXES - Changes in Unrec
INCOME TAXES - Changes in Unrecognized Tax Benefits (Details) - USD ($) $ in Millions | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2018 | |
Changes in unrecognized tax benefits [Roll Forward] | ||
Unrecognized tax benefits at beginning of year | $ 0 | $ 18 |
Tax position changes – decrease from prior periods | (18) | |
Tax positions changes – increase from prior periods | 44 | |
Balance at end of year | $ 44 | $ 0 |
RETIREMENT BENEFITS - Narrative
RETIREMENT BENEFITS - Narrative (Details) - USD ($) | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Defined Benefit Plan Disclosure [Line Items] | ||
Plan asset amortization period | 5 years | |
Pension plans | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Employer contributions | $ 58,000,000 | $ 1,208,000,000 |
Expected future employer contributions, next fiscal year | 0 | |
Actuarial losses | $ (1,679,000,000) | $ (2,346,000,000) |
Change in discount rate | 6000.00% | 1.08% |
Pension plans | Qualified pension plan | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Employer contributions | $ 0 | |
Other postretirement benefit plans | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Employer contributions | 72,000,000 | $ 83,000,000 |
Expected future employer contributions, next fiscal year | 0 | |
Actuarial losses | $ (7,000,000) | $ (223,000,000) |
RETIREMENT BENEFITS - Defined B
RETIREMENT BENEFITS - Defined Benefit Plan Related to Gulf Power (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 |
Pension plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Defined Benefit Plan, Benefit Obligation | $ 16,646 | $ 14,788 | $ 12,763 |
Defined Benefit Plan, Plan Assets, Amount | 15,367 | 14,057 | 11,611 |
Accrued liability | (1,279) | (731) | |
Other postretirement benefit plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Defined Benefit Plan, Benefit Obligation | 1,948 | 1,985 | 1,865 |
Defined Benefit Plan, Plan Assets, Amount | 1,158 | 1,061 | $ 928 |
Accrued liability | $ (790) | $ (924) |
RETIREMENT BENEFITS - Actuarial
RETIREMENT BENEFITS - Actuarial Assumptions (Details) | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Pension plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 3.41% | 4.49% | 3.80% |
Expected long-term return on plan assets | 8.25% | 7.75% | 7.95% |
Annual salary increase, net periodic costs | 4.73% | 4.34% | 4.34% |
Pension plans | Discount rate – interest costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 2.99% | 4.12% | 3.45% |
Pension plans | Discount rate – service costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 3.66% | 4.70% | 3.98% |
Pension plans | Employee benefit obligations | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 2.81% | 3.41% | |
Annual salary increase | 4.80% | 4.73% | |
Other postretirement benefit plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 3.24% | 4.37% | 3.68% |
Expected long-term return on plan assets | 7.25% | 6.86% | 6.83% |
Annual salary increase, net periodic costs | 4.73% | 4.34% | 4.34% |
Other postretirement benefit plans | Discount rate – interest costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 2.80% | 3.98% | 3.29% |
Other postretirement benefit plans | Discount rate – service costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 3.57% | 4.63% | 3.91% |
Other postretirement benefit plans | Employee benefit obligations | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 2.56% | 3.24% | |
Annual salary increase | 4.80% | 4.73% | |
Alabama Power | Pension plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 3.44% | 4.51% | 3.81% |
Expected long-term return on plan assets | 8.25% | 7.75% | 7.95% |
Annual salary increase, net periodic costs | 4.73% | 4.46% | 4.46% |
Alabama Power | Pension plans | Discount rate – interest costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 3.01% | 4.14% | 3.45% |
Alabama Power | Pension plans | Discount rate – service costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 3.69% | 4.73% | 4.00% |
Alabama Power | Pension plans | Employee benefit obligations | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 2.85% | 3.44% | |
Annual salary increase | 4.80% | 4.73% | |
Alabama Power | Other postretirement benefit plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 3.28% | 4.40% | 3.71% |
Expected long-term return on plan assets | 7.36% | 6.76% | 6.83% |
Annual salary increase, net periodic costs | 4.73% | 4.46% | 4.46% |
Alabama Power | Other postretirement benefit plans | Discount rate – interest costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 2.84% | 4.01% | 3.31% |
Alabama Power | Other postretirement benefit plans | Discount rate – service costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 3.61% | 4.67% | 3.93% |
Alabama Power | Other postretirement benefit plans | Employee benefit obligations | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 2.63% | 3.28% | |
Annual salary increase | 4.80% | 4.73% | |
Georgia Power | Pension plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 3.40% | 4.48% | 3.79% |
Expected long-term return on plan assets | 8.25% | 7.75% | 7.95% |
Annual salary increase, net periodic costs | 4.73% | 4.46% | 4.46% |
Georgia Power | Pension plans | Discount rate – interest costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 2.96% | 4.10% | 3.42% |
Georgia Power | Pension plans | Discount rate – service costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 3.67% | 4.72% | 3.99% |
Georgia Power | Pension plans | Employee benefit obligations | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 2.79% | 3.40% | |
Annual salary increase | 4.80% | 4.73% | |
Georgia Power | Other postretirement benefit plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 3.22% | 4.36% | 3.68% |
Expected long-term return on plan assets | 7.05% | 6.85% | 6.80% |
Annual salary increase, net periodic costs | 4.73% | 4.46% | 4.46% |
Georgia Power | Other postretirement benefit plans | Discount rate – interest costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 2.79% | 3.97% | 3.29% |
Georgia Power | Other postretirement benefit plans | Discount rate – service costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 3.57% | 4.64% | 3.91% |
Georgia Power | Other postretirement benefit plans | Employee benefit obligations | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 2.52% | 3.22% | |
Annual salary increase | 4.80% | 4.73% | |
Mississippi Power | Pension plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 3.41% | 4.49% | 3.80% |
Expected long-term return on plan assets | 8.25% | 7.75% | 7.95% |
Annual salary increase, net periodic costs | 4.73% | 4.46% | 4.46% |
Mississippi Power | Pension plans | Discount rate – interest costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 2.99% | 4.12% | 3.46% |
Mississippi Power | Pension plans | Discount rate – service costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 3.67% | 4.73% | 3.99% |
Mississippi Power | Pension plans | Employee benefit obligations | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 2.80% | 3.41% | |
Annual salary increase | 4.80% | 4.73% | |
Mississippi Power | Other postretirement benefit plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 3.22% | 4.35% | 3.68% |
Expected long-term return on plan assets | 7.07% | 6.79% | 6.99% |
Annual salary increase, net periodic costs | 4.73% | 4.46% | 4.46% |
Mississippi Power | Other postretirement benefit plans | Discount rate – interest costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 2.76% | 3.95% | 3.29% |
Mississippi Power | Other postretirement benefit plans | Discount rate – service costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 3.57% | 4.64% | 3.91% |
Mississippi Power | Other postretirement benefit plans | Employee benefit obligations | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 2.53% | 3.22% | |
Annual salary increase | 4.80% | 4.73% | |
Southern Power | Pension plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 3.52% | 4.65% | 3.94% |
Expected long-term return on plan assets | 8.25% | 7.75% | 7.95% |
Annual salary increase, net periodic costs | 4.73% | 4.46% | 4.46% |
Southern Power | Pension plans | Discount rate – interest costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 3.18% | 4.35% | 3.69% |
Southern Power | Pension plans | Discount rate – service costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 3.70% | 4.75% | 4.01% |
Southern Power | Pension plans | Employee benefit obligations | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 2.99% | 3.52% | |
Annual salary increase | 4.80% | 4.73% | |
Southern Power | Other postretirement benefit plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 3.39% | 4.50% | 3.81% |
Expected long-term return on plan assets | 0.00% | 0.00% | 0.00% |
Annual salary increase, net periodic costs | 4.73% | 4.46% | 4.46% |
Southern Power | Other postretirement benefit plans | Discount rate – interest costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 2.97% | 4.14% | 3.47% |
Southern Power | Other postretirement benefit plans | Discount rate – service costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 3.57% | 4.65% | 3.93% |
Southern Power | Other postretirement benefit plans | Employee benefit obligations | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 2.78% | 3.39% | |
Annual salary increase | 4.80% | 4.73% | |
Southern Company Gas | Pension plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 3.39% | 4.47% | 3.74% |
Expected long-term return on plan assets | 8.25% | 7.75% | 7.95% |
Annual salary increase, net periodic costs | 4.73% | 3.07% | 3.07% |
Southern Company Gas | Pension plans | Discount rate – interest costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 2.99% | 4.11% | 3.41% |
Southern Company Gas | Pension plans | Discount rate – service costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 3.53% | 4.57% | 3.84% |
Southern Company Gas | Pension plans | Employee benefit obligations | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 2.75% | 3.39% | |
Annual salary increase | 4.80% | 4.73% | |
Southern Company Gas | Other postretirement benefit plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 3.19% | 4.32% | 3.62% |
Expected long-term return on plan assets | 6.69% | 6.49% | 5.89% |
Annual salary increase, net periodic costs | 4.73% | 3.07% | 3.07% |
Southern Company Gas | Other postretirement benefit plans | Discount rate – interest costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 2.71% | 3.91% | 3.21% |
Southern Company Gas | Other postretirement benefit plans | Discount rate – service costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate, net periodic benefit costs | 3.52% | 4.56% | 3.82% |
Southern Company Gas | Other postretirement benefit plans | Employee benefit obligations | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Discount rate – benefit obligations | 2.46% | 3.19% | |
Annual salary increase | 4.80% | 4.73% |
RETIREMENT BENEFITS - Schedule
RETIREMENT BENEFITS - Schedule of Health Care Cost Trend Rates (Details) - Other postretirement benefit plans | Dec. 31, 2020 |
Pre-65 | |
Defined Benefit Plan Disclosure [Line Items] | |
Initial Cost Trend Rate | 6.00% |
Ultimate Cost Trend Rate | 4.50% |
Post-65 medical | |
Defined Benefit Plan Disclosure [Line Items] | |
Initial Cost Trend Rate | 5.00% |
Ultimate Cost Trend Rate | 4.50% |
Post-65 prescription | |
Defined Benefit Plan Disclosure [Line Items] | |
Initial Cost Trend Rate | 6.25% |
Ultimate Cost Trend Rate | 4.50% |
RETIREMENT BENEFITS - Accumulat
RETIREMENT BENEFITS - Accumulated Benefit Obligation (Details) - Pension plans - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Defined Benefit Plan Disclosure [Line Items] | ||
Total accumulated benefit obligation for the pension plans | $ 14,922 | $ 13,391 |
Alabama Power | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Total accumulated benefit obligation for the pension plans | 3,414 | 3,053 |
Georgia Power | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Total accumulated benefit obligation for the pension plans | 4,657 | 4,222 |
Mississippi Power | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Total accumulated benefit obligation for the pension plans | 683 | 615 |
Southern Power | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Total accumulated benefit obligation for the pension plans | 175 | 151 |
Southern Company Gas | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Total accumulated benefit obligation for the pension plans | $ 1,072 | $ 963 |
RETIREMENT BENEFITS - Changes i
RETIREMENT BENEFITS - Changes in Projected Benefit Obligations and Fair Value of Plan Assets (Details) - USD ($) | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Pension plans | |||
Change in benefit obligation | |||
Benefit obligation at beginning of year | $ 14,788,000,000 | $ 12,763,000,000 | |
Dispositions | (509,000,000) | ||
Service cost | 376,000,000 | 292,000,000 | $ 359,000,000 |
Interest cost | 432,000,000 | 492,000,000 | 464,000,000 |
Benefits paid | (629,000,000) | (596,000,000) | |
Actuarial (gain) loss | 1,679,000,000 | 2,346,000,000 | |
Balance at end of year | 16,646,000,000 | 14,788,000,000 | 12,763,000,000 |
Change in plan assets | |||
Fair value of plan assets at beginning of year | 14,057,000,000 | 11,611,000,000 | |
Dispositions | (509,000,000) | ||
Actual return (loss) on plan assets | 1,881,000,000 | 2,343,000,000 | |
Employer contributions | 58,000,000 | 1,208,000,000 | |
Benefits paid | (629,000,000) | (596,000,000) | |
Fair value of plan assets at end of year | 15,367,000,000 | 14,057,000,000 | 11,611,000,000 |
Accrued liability | (1,279,000,000) | (731,000,000) | |
Other postretirement benefit plans | |||
Change in benefit obligation | |||
Benefit obligation at beginning of year | 1,985,000,000 | 1,865,000,000 | |
Dispositions | (69,000,000) | ||
Service cost | 22,000,000 | 18,000,000 | 24,000,000 |
Interest cost | 54,000,000 | 69,000,000 | 75,000,000 |
Benefits paid | (126,000,000) | (126,000,000) | |
Actuarial (gain) loss | 7,000,000 | 223,000,000 | |
Retiree drug subsidy | 6,000,000 | 5,000,000 | |
Balance at end of year | 1,948,000,000 | 1,985,000,000 | 1,865,000,000 |
Change in plan assets | |||
Fair value of plan assets at beginning of year | 1,061,000,000 | 928,000,000 | |
Dispositions | (18,000,000) | ||
Actual return (loss) on plan assets | 145,000,000 | 189,000,000 | |
Employer contributions | 72,000,000 | 83,000,000 | |
Benefits paid | (120,000,000) | (121,000,000) | |
Fair value of plan assets at end of year | 1,158,000,000 | 1,061,000,000 | 928,000,000 |
Accrued liability | (790,000,000) | (924,000,000) | |
Alabama Power | Pension plans | |||
Change in benefit obligation | |||
Benefit obligation at beginning of year | 3,404,000,000 | 2,816,000,000 | |
Dispositions | 0 | ||
Service cost | 89,000,000 | 69,000,000 | 78,000,000 |
Interest cost | 100,000,000 | 114,000,000 | 101,000,000 |
Benefits paid | (132,000,000) | (125,000,000) | |
Actuarial (gain) loss | 393,000,000 | 530,000,000 | |
Balance at end of year | 3,854,000,000 | 3,404,000,000 | 2,816,000,000 |
Change in plan assets | |||
Fair value of plan assets at beginning of year | 3,357,000,000 | 2,575,000,000 | |
Dispositions | 0 | ||
Actual return (loss) on plan assets | 450,000,000 | 524,000,000 | |
Employer contributions | 9,000,000 | 383,000,000 | |
Benefits paid | (132,000,000) | (125,000,000) | |
Fair value of plan assets at end of year | 3,684,000,000 | 3,357,000,000 | 2,575,000,000 |
Accrued liability | (170,000,000) | (47,000,000) | |
Alabama Power | Other postretirement benefit plans | |||
Change in benefit obligation | |||
Benefit obligation at beginning of year | 462,000,000 | 403,000,000 | |
Dispositions | 0 | ||
Service cost | 6,000,000 | 5,000,000 | 6,000,000 |
Interest cost | 13,000,000 | 16,000,000 | 17,000,000 |
Benefits paid | (29,000,000) | (27,000,000) | |
Actuarial (gain) loss | 9,000,000 | 63,000,000 | |
Retiree drug subsidy | 2,000,000 | 2,000,000 | |
Balance at end of year | 463,000,000 | 462,000,000 | 403,000,000 |
Change in plan assets | |||
Fair value of plan assets at beginning of year | 413,000,000 | 360,000,000 | |
Dispositions | 0 | ||
Actual return (loss) on plan assets | 60,000,000 | 76,000,000 | |
Employer contributions | 12,000,000 | 2,000,000 | |
Benefits paid | (27,000,000) | (25,000,000) | |
Fair value of plan assets at end of year | 458,000,000 | 413,000,000 | 360,000,000 |
Accrued liability | (5,000,000) | (49,000,000) | |
Georgia Power | Pension plans | |||
Change in benefit obligation | |||
Benefit obligation at beginning of year | 4,610,000,000 | 3,905,000,000 | |
Dispositions | 0 | ||
Service cost | 96,000,000 | 74,000,000 | 87,000,000 |
Interest cost | 133,000,000 | 156,000,000 | 139,000,000 |
Benefits paid | (202,000,000) | (194,000,000) | |
Actuarial (gain) loss | 490,000,000 | 669,000,000 | |
Balance at end of year | 5,127,000,000 | 4,610,000,000 | 3,905,000,000 |
Change in plan assets | |||
Fair value of plan assets at beginning of year | 4,442,000,000 | 3,663,000,000 | |
Dispositions | 0 | ||
Actual return (loss) on plan assets | 594,000,000 | 730,000,000 | |
Employer contributions | 10,000,000 | 243,000,000 | |
Benefits paid | (202,000,000) | (194,000,000) | |
Fair value of plan assets at end of year | 4,844,000,000 | 4,442,000,000 | 3,663,000,000 |
Accrued liability | (283,000,000) | (168,000,000) | |
Georgia Power | Other postretirement benefit plans | |||
Change in benefit obligation | |||
Benefit obligation at beginning of year | 742,000,000 | 675,000,000 | |
Dispositions | 0 | ||
Service cost | 6,000,000 | 5,000,000 | 6,000,000 |
Interest cost | 20,000,000 | 26,000,000 | 28,000,000 |
Benefits paid | (46,000,000) | (47,000,000) | |
Actuarial (gain) loss | (26,000,000) | 80,000,000 | |
Retiree drug subsidy | 3,000,000 | 3,000,000 | |
Balance at end of year | 699,000,000 | 742,000,000 | 675,000,000 |
Change in plan assets | |||
Fair value of plan assets at beginning of year | 403,000,000 | 344,000,000 | |
Dispositions | 0 | ||
Actual return (loss) on plan assets | 50,000,000 | 68,000,000 | |
Employer contributions | 17,000,000 | 35,000,000 | |
Benefits paid | (43,000,000) | (44,000,000) | |
Fair value of plan assets at end of year | 427,000,000 | 403,000,000 | 344,000,000 |
Accrued liability | (272,000,000) | (339,000,000) | |
Mississippi Power | Pension plans | |||
Change in benefit obligation | |||
Benefit obligation at beginning of year | 671,000,000 | 557,000,000 | |
Dispositions | 0 | ||
Service cost | 15,000,000 | 12,000,000 | 17,000,000 |
Interest cost | 20,000,000 | 22,000,000 | 20,000,000 |
Benefits paid | (27,000,000) | (26,000,000) | |
Actuarial (gain) loss | 75,000,000 | 106,000,000 | |
Balance at end of year | 754,000,000 | 671,000,000 | 557,000,000 |
Change in plan assets | |||
Fair value of plan assets at beginning of year | 641,000,000 | 505,000,000 | |
Dispositions | 0 | ||
Actual return (loss) on plan assets | 85,000,000 | 103,000,000 | |
Employer contributions | 2,000,000 | 59,000,000 | |
Benefits paid | (27,000,000) | (26,000,000) | |
Fair value of plan assets at end of year | 701,000,000 | 641,000,000 | 505,000,000 |
Accrued liability | (53,000,000) | (30,000,000) | |
Mississippi Power | Other postretirement benefit plans | |||
Change in benefit obligation | |||
Benefit obligation at beginning of year | 87,000,000 | 81,000,000 | |
Dispositions | 0 | ||
Service cost | 1,000,000 | 1,000,000 | 1,000,000 |
Interest cost | 2,000,000 | 3,000,000 | 3,000,000 |
Benefits paid | (6,000,000) | (6,000,000) | |
Actuarial (gain) loss | (3,000,000) | 8,000,000 | |
Retiree drug subsidy | 0 | 0 | |
Balance at end of year | 81,000,000 | 87,000,000 | 81,000,000 |
Change in plan assets | |||
Fair value of plan assets at beginning of year | 26,000,000 | 23,000,000 | |
Dispositions | 0 | ||
Actual return (loss) on plan assets | 3,000,000 | 4,000,000 | |
Employer contributions | 4,000,000 | 5,000,000 | |
Benefits paid | (6,000,000) | (6,000,000) | |
Fair value of plan assets at end of year | 27,000,000 | 26,000,000 | 23,000,000 |
Accrued liability | (54,000,000) | (61,000,000) | |
Southern Power | Pension plans | |||
Change in benefit obligation | |||
Benefit obligation at beginning of year | 185,000,000 | 123,000,000 | |
Dispositions | 0 | ||
Service cost | 8,000,000 | 7,000,000 | 9,000,000 |
Interest cost | 6,000,000 | 5,000,000 | 5,000,000 |
Benefits paid | (6,000,000) | (4,000,000) | |
Actuarial (gain) loss | 24,000,000 | 54,000,000 | |
Balance at end of year | 217,000,000 | 185,000,000 | 123,000,000 |
Change in plan assets | |||
Fair value of plan assets at beginning of year | 169,000,000 | 123,000,000 | |
Dispositions | 0 | ||
Actual return (loss) on plan assets | 22,000,000 | 43,000,000 | |
Employer contributions | 1,000,000 | 7,000,000 | |
Benefits paid | (6,000,000) | (4,000,000) | |
Fair value of plan assets at end of year | 186,000,000 | 169,000,000 | 123,000,000 |
Accrued liability | (31,000,000) | (16,000,000) | |
Southern Power | Other postretirement benefit plans | |||
Change in benefit obligation | |||
Benefit obligation at beginning of year | 11,000,000 | 9,000,000 | |
Dispositions | 0 | ||
Service cost | 1,000,000 | 1,000,000 | 1,000,000 |
Interest cost | 0 | 0 | 0 |
Benefits paid | 0 | (1,000,000) | |
Actuarial (gain) loss | 0 | 2,000,000 | |
Retiree drug subsidy | 0 | 0 | |
Balance at end of year | 12,000,000 | 11,000,000 | 9,000,000 |
Change in plan assets | |||
Fair value of plan assets at beginning of year | 0 | 0 | |
Dispositions | 0 | ||
Actual return (loss) on plan assets | 0 | 0 | |
Employer contributions | 0 | 1,000,000 | |
Benefits paid | 0 | (1,000,000) | |
Fair value of plan assets at end of year | 0 | 0 | 0 |
Accrued liability | (12,000,000) | (11,000,000) | |
Southern Company Gas | Pension plans | |||
Change in benefit obligation | |||
Benefit obligation at beginning of year | 1,067,000,000 | 907,000,000 | |
Dispositions | 0 | ||
Service cost | 33,000,000 | 25,000,000 | 34,000,000 |
Interest cost | 31,000,000 | 36,000,000 | 39,000,000 |
Benefits paid | (69,000,000) | (64,000,000) | |
Actuarial (gain) loss | 127,000,000 | 163,000,000 | |
Balance at end of year | 1,189,000,000 | 1,067,000,000 | 907,000,000 |
Change in plan assets | |||
Fair value of plan assets at beginning of year | 1,050,000,000 | 798,000,000 | |
Dispositions | 0 | ||
Actual return (loss) on plan assets | 139,000,000 | 172,000,000 | |
Employer contributions | 3,000,000 | 144,000,000 | |
Benefits paid | (69,000,000) | (64,000,000) | |
Fair value of plan assets at end of year | 1,123,000,000 | 1,050,000,000 | 798,000,000 |
Accrued liability | (66,000,000) | (17,000,000) | |
Southern Company Gas | Other postretirement benefit plans | |||
Change in benefit obligation | |||
Benefit obligation at beginning of year | 250,000,000 | 244,000,000 | |
Dispositions | 0 | ||
Service cost | 2,000,000 | 1,000,000 | 2,000,000 |
Interest cost | 7,000,000 | 9,000,000 | 10,000,000 |
Benefits paid | (17,000,000) | (17,000,000) | |
Actuarial (gain) loss | 6,000,000 | 13,000,000 | |
Retiree drug subsidy | 0 | 0 | |
Balance at end of year | 248,000,000 | 250,000,000 | 244,000,000 |
Change in plan assets | |||
Fair value of plan assets at beginning of year | 115,000,000 | 98,000,000 | |
Dispositions | 0 | ||
Actual return (loss) on plan assets | 18,000,000 | 21,000,000 | |
Employer contributions | 12,000,000 | 13,000,000 | |
Benefits paid | (17,000,000) | (17,000,000) | |
Fair value of plan assets at end of year | 128,000,000 | 115,000,000 | $ 98,000,000 |
Accrued liability | (120,000,000) | $ (135,000,000) | |
Qualified pension plan | Pension plans | |||
Change in benefit obligation | |||
Balance at end of year | 15,818,000,000 | ||
Change in plan assets | |||
Employer contributions | 0 | ||
Qualified pension plan | Alabama Power | Pension plans | |||
Change in benefit obligation | |||
Balance at end of year | 3,719,000,000 | ||
Qualified pension plan | Georgia Power | Pension plans | |||
Change in benefit obligation | |||
Balance at end of year | 4,977,000,000 | ||
Qualified pension plan | Mississippi Power | Pension plans | |||
Change in benefit obligation | |||
Balance at end of year | 718,000,000 | ||
Qualified pension plan | Southern Power | Pension plans | |||
Change in benefit obligation | |||
Balance at end of year | 187,000,000 | ||
Qualified pension plan | Southern Company Gas | Pension plans | |||
Change in benefit obligation | |||
Balance at end of year | 1,114,000,000 | ||
Non-qualified pension plan | Pension plans | |||
Change in benefit obligation | |||
Balance at end of year | 828,000,000 | ||
Non-qualified pension plan | Alabama Power | Pension plans | |||
Change in benefit obligation | |||
Balance at end of year | 135,000,000 | ||
Non-qualified pension plan | Georgia Power | Pension plans | |||
Change in benefit obligation | |||
Balance at end of year | 150,000,000 | ||
Non-qualified pension plan | Mississippi Power | Pension plans | |||
Change in benefit obligation | |||
Balance at end of year | 36,000,000 | ||
Non-qualified pension plan | Southern Power | Pension plans | |||
Change in benefit obligation | |||
Balance at end of year | 30,000,000 | ||
Non-qualified pension plan | Southern Company Gas | Pension plans | |||
Change in benefit obligation | |||
Balance at end of year | $ 75,000,000 |
RETIREMENT BENEFITS - Amounts R
RETIREMENT BENEFITS - Amounts Recognized in Balance Sheets and Amounts in AOCI (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Defined Benefit Plan Disclosure [Line Items] | ||
Other regulatory assets, deferred | $ 7,198 | $ 6,805 |
Other deferred charges and assets | 1,288 | 1,071 |
Other current liabilities | (968) | (830) |
Employee benefit obligations | (2,213) | (1,814) |
Other regulatory liabilities, deferred | (251) | (256) |
Pension plans | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Prepaid pension costs | 2 | |
Other regulatory assets, deferred | 4,655 | 4,072 |
Other deferred charges and assets | 0 | 0 |
Other current liabilities | (52) | (54) |
Employee benefit obligations | (1,227) | (679) |
Other regulatory liabilities, deferred | (34) | (79) |
AOCI | 245 | 185 |
Other postretirement benefit plans | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Other regulatory assets, deferred | 137 | 183 |
Other current liabilities | (5) | (5) |
Employee benefit obligations | (785) | (919) |
Other regulatory liabilities, deferred | (86) | (62) |
AOCI | 8 | 2 |
Alabama Power | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Other regulatory assets, deferred | 2,162 | 2,016 |
Other deferred charges and assets | 273 | 269 |
Other current liabilities | (107) | (105) |
Employee benefit obligations | (214) | (206) |
Other regulatory liabilities, deferred | (124) | (146) |
Alabama Power | Pension plans | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Prepaid pension costs | 71 | |
Other regulatory assets, deferred | 1,286 | 1,130 |
Other deferred charges and assets | 0 | 0 |
Other current liabilities | (9) | (8) |
Employee benefit obligations | (161) | (110) |
Other regulatory liabilities, deferred | 0 | 0 |
AOCI | 0 | 0 |
Alabama Power | Other postretirement benefit plans | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Other regulatory assets, deferred | 0 | 3 |
Other current liabilities | 0 | 0 |
Employee benefit obligations | (5) | (49) |
Other regulatory liabilities, deferred | (21) | (2) |
AOCI | 0 | 0 |
Georgia Power | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Other regulatory assets, deferred | 2,692 | 2,716 |
Other deferred charges and assets | 479 | 500 |
Other current liabilities | (254) | (187) |
Employee benefit obligations | (586) | (540) |
Georgia Power | Pension plans | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Prepaid pension costs | 0 | |
Other regulatory assets, deferred | 1,598 | 1,416 |
Other deferred charges and assets | 0 | 0 |
Other current liabilities | (10) | (11) |
Employee benefit obligations | (273) | (157) |
Other regulatory liabilities, deferred | 0 | 0 |
AOCI | 0 | 0 |
Georgia Power | Other postretirement benefit plans | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Other regulatory assets, deferred | 47 | 96 |
Other current liabilities | 0 | 0 |
Employee benefit obligations | (272) | (339) |
Other regulatory liabilities, deferred | 0 | 0 |
AOCI | 0 | 0 |
Mississippi Power | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Other regulatory assets, deferred | 388 | 360 |
Other deferred charges and assets | 55 | 34 |
Other current liabilities | (40) | (64) |
Employee benefit obligations | (113) | (99) |
Other regulatory liabilities, deferred | (15) | (76) |
Mississippi Power | Pension plans | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Prepaid pension costs | 2 | |
Other regulatory assets, deferred | 235 | 204 |
Other deferred charges and assets | 0 | 0 |
Other current liabilities | (2) | (2) |
Employee benefit obligations | (51) | (30) |
Other regulatory liabilities, deferred | 0 | 0 |
AOCI | 0 | 0 |
Mississippi Power | Other postretirement benefit plans | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Other regulatory assets, deferred | 5 | 10 |
Other current liabilities | 0 | 0 |
Employee benefit obligations | (54) | (61) |
Other regulatory liabilities, deferred | 0 | 0 |
AOCI | 0 | 0 |
Southern Power | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Other deferred charges and assets | 293 | 216 |
Other current liabilities | (132) | (132) |
Southern Power | Pension plans | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Prepaid pension costs | 10 | |
Other regulatory assets, deferred | 0 | 0 |
Other deferred charges and assets | 0 | 0 |
Other current liabilities | (2) | (2) |
Employee benefit obligations | (29) | (24) |
Other regulatory liabilities, deferred | 0 | 0 |
AOCI | 60 | 46 |
Southern Power | Other postretirement benefit plans | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Other regulatory assets, deferred | 0 | 0 |
Other current liabilities | 0 | 0 |
Employee benefit obligations | (12) | (11) |
Other regulatory liabilities, deferred | 0 | 0 |
AOCI | 3 | 2 |
Southern Company Gas | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Other regulatory assets, deferred | 615 | 618 |
Other deferred charges and assets | 235 | 207 |
Other current liabilities | (150) | (149) |
Employee benefit obligations | (283) | (265) |
Southern Company Gas | Pension plans | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Prepaid pension costs | 0 | |
Other regulatory assets, deferred | 205 | 172 |
Other deferred charges and assets | 70 | 82 |
Other current liabilities | (2) | (2) |
Employee benefit obligations | (134) | (97) |
Other regulatory liabilities, deferred | 0 | 0 |
AOCI | 1 | (14) |
Regulatory asset | 224 | 252 |
Southern Company Gas | Other postretirement benefit plans | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Other regulatory assets, deferred | (23) | (11) |
Other current liabilities | 0 | 0 |
Employee benefit obligations | (120) | (135) |
Other regulatory liabilities, deferred | 0 | 0 |
AOCI | 0 | (4) |
Regulatory asset | $ 47 | $ 50 |
RETIREMENT BENEFITS - Component
RETIREMENT BENEFITS - Components of Accumulated OCI and Changes in Regulatory Assets (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | $ 31,759 | $ 29,039 | $ 25,528 |
Total other comprehensive income (loss) | (75) | (118) | 26 |
Ending balance | 32,234 | 31,759 | 29,039 |
Pension and Other Postretirement Benefit Plans | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | (142) | ||
Total other comprehensive income (loss) | (45) | ||
Ending balance | (187) | (142) | |
Pension plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Prior service cost | (3) | (3) | |
Net (gain) loss | 248 | 188 | |
Total AOCI | 245 | 185 | |
Pension plans | Regulatory Assets | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Prior service cost | 11 | 13 | |
Net (gain) loss | 4,610 | 3,980 | |
Regulatory amortization | 0 | 0 | |
Regulatory asset | 4,621 | 3,993 | |
Pension plans | Pension and Other Postretirement Benefit Plans | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 185 | 97 | |
Reclassification adjustments | (14) | ||
Total other comprehensive income (loss) | 60 | ||
Ending balance | 245 | 185 | 97 |
Pension plans | Pension and Other Postretirement Benefit Plans | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 3,993 | 3,458 | |
Reclassification adjustments | (256) | (122) | |
Total other comprehensive income (loss) | 628 | 535 | |
Ending balance | 4,621 | 3,993 | 3,458 |
Pension plans | Net (gain) loss | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | (74) | (88) | |
Reclassification adjustments | (14) | ||
Pension plans | Net (gain) loss | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | (884) | (801) | |
Reclassification adjustments | (255) | (119) | |
Pension plans | Dispositions | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 144 | ||
Pension plans | Change in prior service costs | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | 0 | ||
Pension plans | Change in prior service costs | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | (1) | (3) | |
Pension plans | Amortization of regulatory assets | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | 0 | 0 | |
Other postretirement benefit plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Prior service cost | 1 | 1 | |
Net (gain) loss | 7 | 1 | |
Total AOCI | 8 | 2 | |
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | 4 | 1 | |
Other postretirement benefit plans | Regulatory Assets | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Prior service cost | 12 | 11 | |
Net (gain) loss | 39 | 110 | |
Regulatory amortization | 0 | 0 | |
Regulatory asset | 51 | 121 | |
Other postretirement benefit plans | Pension and Other Postretirement Benefit Plans | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 2 | (4) | |
Total other comprehensive income (loss) | 6 | 6 | |
Ending balance | 8 | 2 | (4) |
Other postretirement benefit plans | Pension and Other Postretirement Benefit Plans | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 121 | 22 | |
Reclassification adjustments | (5) | (1) | |
Total other comprehensive income (loss) | (70) | 99 | |
Ending balance | 51 | 121 | 22 |
Other postretirement benefit plans | Net (gain) loss | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 2 | 5 | |
Other postretirement benefit plans | Net (gain) loss | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 65 | (90) | |
Reclassification adjustments | (6) | 2 | |
Other postretirement benefit plans | Dispositions | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | (5) | ||
Other postretirement benefit plans | Change in prior service costs | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | (5) | ||
Reclassification adjustments | 1 | (3) | |
Other postretirement benefit plans | Amortization of regulatory assets | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | 0 | 0 | |
Alabama Power | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 8,955 | 7,477 | 6,829 |
Total other comprehensive income (loss) | 4 | 4 | 4 |
Ending balance | 9,810 | 8,955 | 7,477 |
Alabama Power | Pension plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Total AOCI | 0 | 0 | |
Alabama Power | Pension plans | Regulatory Assets | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Prior service cost | 5 | 6 | |
Net (gain) loss | 1,281 | 1,124 | |
Regulatory amortization | 0 | 0 | |
Regulatory asset | 1,286 | 1,130 | |
Alabama Power | Pension plans | Pension and Other Postretirement Benefit Plans | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 1,130 | 955 | |
Reclassification adjustments | (72) | (38) | |
Total other comprehensive income (loss) | 156 | 175 | |
Ending balance | 1,286 | 1,130 | 955 |
Alabama Power | Pension plans | Net (gain) loss | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | (228) | (213) | |
Reclassification adjustments | (71) | (37) | |
Alabama Power | Pension plans | Dispositions | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 0 | ||
Alabama Power | Pension plans | Change in prior service costs | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | (1) | (1) | |
Alabama Power | Pension plans | Amortization of regulatory assets | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | 0 | 0 | |
Alabama Power | Other postretirement benefit plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Total AOCI | 0 | 0 | |
Alabama Power | Other postretirement benefit plans | Regulatory Assets | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Prior service cost | 3 | 3 | |
Net (gain) loss | (24) | (2) | |
Regulatory amortization | 0 | 0 | |
Regulatory asset | 1 | ||
Regulatory liabilities | (21) | ||
Alabama Power | Other postretirement benefit plans | Pension and Other Postretirement Benefit Plans | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 1 | (9) | |
Reclassification adjustments | 0 | (4) | |
Total other comprehensive income (loss) | (22) | 10 | |
Ending balance | (21) | 1 | (9) |
Alabama Power | Other postretirement benefit plans | Net (gain) loss | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 22 | (14) | |
Reclassification adjustments | 0 | 0 | |
Alabama Power | Other postretirement benefit plans | Dispositions | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 0 | ||
Alabama Power | Other postretirement benefit plans | Change in prior service costs | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 0 | ||
Reclassification adjustments | 0 | (4) | |
Alabama Power | Other postretirement benefit plans | Amortization of regulatory assets | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | 0 | 0 | |
Georgia Power | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 15,065 | 14,323 | 11,931 |
Total other comprehensive income (loss) | 4 | (42) | 3 |
Ending balance | 16,501 | 15,065 | 14,323 |
Georgia Power | Pension plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Total AOCI | 0 | 0 | |
Georgia Power | Pension plans | Regulatory Assets | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Prior service cost | 9 | 10 | |
Net (gain) loss | 1,589 | 1,406 | |
Regulatory amortization | 0 | 0 | |
Regulatory asset | 1,598 | 1,416 | |
Georgia Power | Pension plans | Pension and Other Postretirement Benefit Plans | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 1,416 | 1,230 | |
Reclassification adjustments | (87) | (45) | |
Total other comprehensive income (loss) | 182 | 186 | |
Ending balance | 1,598 | 1,416 | 1,230 |
Georgia Power | Pension plans | Net (gain) loss | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | (269) | (231) | |
Reclassification adjustments | (86) | (44) | |
Georgia Power | Pension plans | Dispositions | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 0 | ||
Georgia Power | Pension plans | Change in prior service costs | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | (1) | (1) | |
Georgia Power | Pension plans | Amortization of regulatory assets | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | 0 | 0 | |
Georgia Power | Other postretirement benefit plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Total AOCI | 0 | 0 | |
Georgia Power | Other postretirement benefit plans | Regulatory Assets | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Prior service cost | 5 | 4 | |
Net (gain) loss | 42 | 92 | |
Regulatory amortization | 0 | 0 | |
Regulatory asset | 47 | 96 | |
Georgia Power | Other postretirement benefit plans | Pension and Other Postretirement Benefit Plans | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 96 | 60 | |
Reclassification adjustments | (2) | (1) | |
Total other comprehensive income (loss) | (49) | 36 | |
Ending balance | 47 | 96 | 60 |
Georgia Power | Other postretirement benefit plans | Net (gain) loss | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 47 | (37) | |
Reclassification adjustments | (3) | (1) | |
Georgia Power | Other postretirement benefit plans | Dispositions | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 0 | ||
Georgia Power | Other postretirement benefit plans | Change in prior service costs | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 0 | ||
Reclassification adjustments | 1 | 0 | |
Georgia Power | Other postretirement benefit plans | Amortization of regulatory assets | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | 0 | 0 | |
Mississippi Power | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 1,652 | 1,609 | 1,358 |
Total other comprehensive income (loss) | 1 | 1 | 0 |
Ending balance | 1,742 | 1,652 | 1,609 |
Mississippi Power | Pension plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Total AOCI | 0 | 0 | |
Mississippi Power | Pension plans | Regulatory Assets | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Prior service cost | 2 | 2 | |
Net (gain) loss | 233 | 201 | |
Regulatory amortization | 0 | 0 | |
Regulatory asset | 235 | 203 | |
Mississippi Power | Pension plans | Pension and Other Postretirement Benefit Plans | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 203 | 167 | |
Reclassification adjustments | (13) | (6) | |
Total other comprehensive income (loss) | 32 | 36 | |
Ending balance | 235 | 203 | 167 |
Mississippi Power | Pension plans | Net (gain) loss | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | (45) | (42) | |
Reclassification adjustments | (13) | (6) | |
Mississippi Power | Pension plans | Dispositions | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 0 | ||
Mississippi Power | Pension plans | Change in prior service costs | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | 0 | 0 | |
Mississippi Power | Pension plans | Amortization of regulatory assets | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | 0 | 0 | |
Mississippi Power | Other postretirement benefit plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Total AOCI | 0 | 0 | |
Mississippi Power | Other postretirement benefit plans | Regulatory Assets | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Prior service cost | 0 | 0 | |
Net (gain) loss | 5 | 10 | |
Regulatory amortization | 0 | 0 | |
Regulatory asset | 5 | 10 | |
Mississippi Power | Other postretirement benefit plans | Pension and Other Postretirement Benefit Plans | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 10 | 4 | |
Reclassification adjustments | 0 | 0 | |
Total other comprehensive income (loss) | (5) | 6 | |
Ending balance | 5 | 10 | 4 |
Mississippi Power | Other postretirement benefit plans | Net (gain) loss | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 5 | (6) | |
Reclassification adjustments | 0 | 0 | |
Mississippi Power | Other postretirement benefit plans | Dispositions | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 0 | ||
Mississippi Power | Other postretirement benefit plans | Change in prior service costs | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 0 | ||
Reclassification adjustments | 0 | 0 | |
Mississippi Power | Other postretirement benefit plans | Amortization of regulatory assets | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | 0 | 0 | |
Southern Power | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 6,622 | 7,284 | 6,498 |
Total other comprehensive income (loss) | (42) | (42) | 14 |
Ending balance | 6,631 | 6,622 | 7,284 |
Southern Power | Pension and Other Postretirement Benefit Plans | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | (37) | ||
Total other comprehensive income (loss) | (10) | ||
Ending balance | (47) | (37) | |
Southern Power | Pension plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Prior service cost | 0 | 0 | |
Net (gain) loss | 60 | 46 | |
Total AOCI | 60 | 46 | |
Southern Power | Pension plans | Pension and Other Postretirement Benefit Plans | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 46 | 26 | |
Reclassification adjustments | (2) | ||
Total other comprehensive income (loss) | 14 | ||
Ending balance | 60 | 46 | 26 |
Southern Power | Pension plans | Net (gain) loss | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | (16) | (20) | |
Reclassification adjustments | (2) | ||
Southern Power | Pension plans | Change in prior service costs | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | 0 | ||
Southern Power | Other postretirement benefit plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Prior service cost | 0 | 0 | |
Net (gain) loss | 3 | 2 | |
Total AOCI | 3 | 2 | |
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | 0 | 0 | |
Southern Power | Other postretirement benefit plans | Pension and Other Postretirement Benefit Plans | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 2 | 1 | |
Total other comprehensive income (loss) | 1 | 1 | |
Ending balance | 3 | 2 | 1 |
Southern Power | Other postretirement benefit plans | Net (gain) loss | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 1 | 1 | |
Southern Company Gas | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 9,506 | 8,570 | 9,022 |
Total other comprehensive income (loss) | (29) | (19) | 2 |
Ending balance | 9,767 | 9,506 | 8,570 |
Southern Company Gas | Pension and Other Postretirement Benefit Plans | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 13 | ||
Total other comprehensive income (loss) | (15) | ||
Ending balance | (2) | 13 | |
Southern Company Gas | Pension plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Prior service cost | (4) | (6) | |
Net (gain) loss | 5 | (8) | |
Total AOCI | 1 | (14) | |
Regulatory asset | 224 | 252 | |
Southern Company Gas | Pension plans | Regulatory Assets | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Prior service cost | (13) | (15) | |
Net (gain) loss | 135 | 113 | |
Regulatory amortization | 83 | 74 | |
Regulatory asset | 205 | 172 | |
Southern Company Gas | Pension plans | Pension and Other Postretirement Benefit Plans | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | (14) | (44) | |
Reclassification adjustments | 0 | ||
Total other comprehensive income (loss) | 15 | ||
Ending balance | 1 | (14) | (44) |
Southern Company Gas | Pension plans | Pension and Other Postretirement Benefit Plans | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | 172 | 160 | |
Reclassification adjustments | (12) | (18) | |
Total other comprehensive income (loss) | 33 | 12 | |
Ending balance | 205 | 172 | 160 |
Southern Company Gas | Pension plans | Net (gain) loss | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | (15) | (30) | |
Reclassification adjustments | (1) | ||
Southern Company Gas | Pension plans | Net (gain) loss | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | (45) | (30) | |
Reclassification adjustments | (8) | 0 | |
Southern Company Gas | Pension plans | Dispositions | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 0 | ||
Southern Company Gas | Pension plans | Change in prior service costs | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | 1 | ||
Southern Company Gas | Pension plans | Change in prior service costs | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | 2 | 2 | |
Southern Company Gas | Pension plans | Amortization of regulatory assets | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | (6) | (20) | |
Southern Company Gas | Other postretirement benefit plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Prior service cost | 1 | 1 | |
Net (gain) loss | (1) | (5) | |
Total AOCI | 0 | (4) | |
Regulatory asset | 47 | 50 | |
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | 4 | 0 | |
Southern Company Gas | Other postretirement benefit plans | Regulatory Assets | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Prior service cost | 1 | 1 | |
Net (gain) loss | (49) | (43) | |
Regulatory amortization | 25 | 31 | |
Regulatory liabilities | (23) | (11) | |
Southern Company Gas | Other postretirement benefit plans | Pension and Other Postretirement Benefit Plans | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | (4) | (4) | |
Total other comprehensive income (loss) | 4 | 0 | |
Ending balance | 0 | (4) | (4) |
Southern Company Gas | Other postretirement benefit plans | Pension and Other Postretirement Benefit Plans | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Beginning balance | (11) | (4) | |
Reclassification adjustments | (7) | (6) | |
Total other comprehensive income (loss) | (12) | (7) | |
Ending balance | (23) | (11) | $ (4) |
Southern Company Gas | Other postretirement benefit plans | Net (gain) loss | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 0 | 0 | |
Southern Company Gas | Other postretirement benefit plans | Net (gain) loss | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 5 | 1 | |
Reclassification adjustments | 0 | 0 | |
Southern Company Gas | Other postretirement benefit plans | Dispositions | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 0 | ||
Southern Company Gas | Other postretirement benefit plans | Change in prior service costs | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Other comprehensive (income) loss | 0 | ||
Reclassification adjustments | 0 | 0 | |
Southern Company Gas | Other postretirement benefit plans | Amortization of regulatory assets | Regulatory Assets | |||
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] | |||
Reclassification adjustments | $ (7) | $ (6) |
RETIREMENT BENEFITS - Compone_2
RETIREMENT BENEFITS - Components of Net Periodic Benefit Cost and Estimated Future Benefit Payments (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Pension plans | |||
Components of net periodic | |||
Service cost | $ 376 | $ 292 | $ 359 |
Interest cost | 432 | 492 | 464 |
Expected return on plan assets | (1,100) | (885) | (943) |
Recognized net (gain) loss | 269 | 120 | 213 |
Net amortization | 1 | 2 | 4 |
Prior service cost | 0 | 0 | 0 |
Total change | (22) | 21 | 97 |
Benefit payments: | |||
2021 | 651 | ||
2022 | 678 | ||
2023 | 702 | ||
2024 | 725 | ||
2025 | 748 | ||
2026 to 2030 | 4,024 | ||
Other postretirement benefit plans | |||
Components of net periodic | |||
Service cost | 22 | 18 | 24 |
Interest cost | 54 | 69 | 75 |
Expected return on plan assets | (72) | (65) | (69) |
Prior service cost | 1 | 0 | 21 |
Total change | 5 | 22 | 51 |
Benefit payments: | |||
2021 | 115 | ||
2022 | 113 | ||
2023 | 111 | ||
2024 | 110 | ||
2025 | 113 | ||
2026 to 2030 | 550 | ||
Alabama Power | Pension plans | |||
Components of net periodic | |||
Service cost | 89 | 69 | 78 |
Interest cost | 100 | 114 | 101 |
Expected return on plan assets | (264) | (206) | (207) |
Recognized net (gain) loss | 71 | 37 | 54 |
Net amortization | 1 | 0 | 1 |
Prior service cost | 0 | 0 | 0 |
Total change | (3) | 14 | 27 |
Benefit payments: | |||
2021 | 141 | ||
2022 | 147 | ||
2023 | 154 | ||
2024 | 158 | ||
2025 | 165 | ||
2026 to 2030 | 895 | ||
Alabama Power | Other postretirement benefit plans | |||
Components of net periodic | |||
Service cost | 6 | 5 | 6 |
Interest cost | 13 | 16 | 17 |
Expected return on plan assets | (29) | (26) | (26) |
Prior service cost | 0 | 4 | 5 |
Total change | (10) | (1) | 2 |
Benefit payments: | |||
2021 | 25 | ||
2022 | 25 | ||
2023 | 25 | ||
2024 | 24 | ||
2025 | 25 | ||
2026 to 2030 | 127 | ||
Georgia Power | Pension plans | |||
Components of net periodic | |||
Service cost | 96 | 74 | 87 |
Interest cost | 133 | 156 | 139 |
Expected return on plan assets | (347) | (292) | (296) |
Recognized net (gain) loss | 86 | 44 | 69 |
Net amortization | 1 | 1 | 2 |
Prior service cost | 0 | 0 | 0 |
Total change | (31) | (17) | 1 |
Benefit payments: | |||
2021 | 208 | ||
2022 | 215 | ||
2023 | 222 | ||
2024 | 229 | ||
2025 | 235 | ||
2026 to 2030 | 1,244 | ||
Georgia Power | Other postretirement benefit plans | |||
Components of net periodic | |||
Service cost | 6 | 5 | 6 |
Interest cost | 20 | 26 | 28 |
Expected return on plan assets | (26) | (25) | (25) |
Prior service cost | 2 | 1 | 10 |
Total change | 2 | 7 | 19 |
Benefit payments: | |||
2021 | 42 | ||
2022 | 41 | ||
2023 | 40 | ||
2024 | 38 | ||
2025 | 40 | ||
2026 to 2030 | 199 | ||
Mississippi Power | Pension plans | |||
Components of net periodic | |||
Service cost | 15 | 12 | 17 |
Interest cost | 20 | 22 | 20 |
Expected return on plan assets | (51) | (40) | (41) |
Recognized net (gain) loss | 13 | 6 | 10 |
Net amortization | 0 | 0 | 0 |
Prior service cost | 0 | 0 | 0 |
Total change | (3) | 0 | 6 |
Benefit payments: | |||
2021 | 29 | ||
2022 | 30 | ||
2023 | 31 | ||
2024 | 32 | ||
2025 | 33 | ||
2026 to 2030 | 181 | ||
Mississippi Power | Other postretirement benefit plans | |||
Components of net periodic | |||
Service cost | 1 | 1 | 1 |
Interest cost | 2 | 3 | 3 |
Expected return on plan assets | (1) | (2) | (2) |
Prior service cost | 0 | 0 | 1 |
Total change | 2 | 2 | 3 |
Benefit payments: | |||
2021 | 6 | ||
2022 | 5 | ||
2023 | 5 | ||
2024 | 4 | ||
2025 | 5 | ||
2026 to 2030 | 23 | ||
Southern Power | Pension plans | |||
Components of net periodic | |||
Service cost | 8 | 7 | 9 |
Interest cost | 6 | 5 | 5 |
Expected return on plan assets | (13) | (10) | (10) |
Recognized net (gain) loss | 2 | 1 | 1 |
Net amortization | 0 | 0 | 0 |
Prior service cost | 0 | 0 | 0 |
Total change | 3 | 3 | 5 |
Benefit payments: | |||
2021 | 6 | ||
2022 | 6 | ||
2023 | 6 | ||
2024 | 6 | ||
2025 | 7 | ||
2026 to 2030 | 38 | ||
Southern Power | Other postretirement benefit plans | |||
Components of net periodic | |||
Service cost | 1 | 1 | 1 |
Interest cost | 0 | 0 | 0 |
Expected return on plan assets | 0 | 0 | 0 |
Prior service cost | 0 | 0 | 0 |
Total change | 1 | 1 | 1 |
Benefit payments: | |||
2021 | 0 | ||
2022 | 0 | ||
2023 | 0 | ||
2024 | 1 | ||
2025 | 1 | ||
2026 to 2030 | 3 | ||
Southern Company Gas | Pension plans | |||
Components of net periodic | |||
Service cost | 33 | 25 | 34 |
Interest cost | 31 | 36 | 39 |
Expected return on plan assets | (75) | (60) | (75) |
Recognized net (gain) loss | 6 | 2 | 12 |
Net amortization | 15 | 14 | 15 |
Prior service cost | (3) | (3) | (2) |
Total change | 7 | 14 | 23 |
Benefit payments: | |||
2021 | 66 | ||
2022 | 66 | ||
2023 | 66 | ||
2024 | 65 | ||
2025 | 65 | ||
2026 to 2030 | 330 | ||
Southern Company Gas | Other postretirement benefit plans | |||
Components of net periodic | |||
Service cost | 2 | 1 | 2 |
Interest cost | 7 | 9 | 10 |
Expected return on plan assets | (10) | (7) | (7) |
Prior service cost | 6 | 6 | 6 |
Total change | 5 | $ 9 | $ 11 |
Benefit payments: | |||
2021 | 18 | ||
2022 | 18 | ||
2023 | 18 | ||
2024 | 17 | ||
2025 | 17 | ||
2026 to 2030 | $ 76 |
RETIREMENT BENEFITS - Fair Valu
RETIREMENT BENEFITS - Fair Values of Pension Plan and Other Postretirement Benefit Plan Assets (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Assets Fair Value | ||
Target plan asset allocations | 100.00% | |
Actual plan asset allocations | 100.00% | |
Pension plans | ||
Assets Fair Value | ||
Plan assets | $ 15,430 | $ 14,119 |
Target plan asset allocations | 100.00% | |
Actual plan asset allocations | 100.00% | |
Pension plans | Equity | ||
Assets Fair Value | ||
Target plan asset allocations | 51.00% | 51.00% |
Actual plan asset allocations | 56.00% | 51.00% |
Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | $ 4,099 | $ 3,118 |
Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | $ 4,157 | $ 3,646 |
Pension plans | Fixed income | ||
Assets Fair Value | ||
Target plan asset allocations | 23.00% | 23.00% |
Actual plan asset allocations | 23.00% | 29.00% |
Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | $ 951 | $ 965 |
Pension plans | Mortgage- and asset-backed securities | ||
Assets Fair Value | ||
Plan assets | 9 | 9 |
Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 1,673 | 1,315 |
Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 772 | 684 |
Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 361 | 1,317 |
Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | $ 2,138 | $ 1,957 |
Target plan asset allocations | 14.00% | 14.00% |
Actual plan asset allocations | 13.00% | 12.00% |
Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | $ 166 | $ 155 |
Target plan asset allocations | 3.00% | 3.00% |
Actual plan asset allocations | 1.00% | 1.00% |
Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | $ 1,104 | $ 953 |
Target plan asset allocations | 9.00% | 9.00% |
Actual plan asset allocations | 7.00% | 7.00% |
Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | $ 1,159 | $ 1,060 |
Target plan asset allocations | 100.00% | 100.00% |
Actual plan asset allocations | 100.00% | 100.00% |
Other postretirement benefit plans | Equity | ||
Assets Fair Value | ||
Target plan asset allocations | 63.00% | 63.00% |
Actual plan asset allocations | 66.00% | 64.00% |
Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | $ 211 | $ 176 |
Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | $ 173 | $ 149 |
Other postretirement benefit plans | Fixed income | ||
Assets Fair Value | ||
Target plan asset allocations | 28.00% | 28.00% |
Actual plan asset allocations | 27.00% | 30.00% |
Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | $ 32 | $ 31 |
Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 44 | 35 |
Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 86 | 82 |
Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 15 | 42 |
Other postretirement benefit plans | Trust-owned life insurance | ||
Assets Fair Value | ||
Plan assets | 508 | 463 |
Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | $ 57 | $ 53 |
Target plan asset allocations | 5.00% | 5.00% |
Actual plan asset allocations | 5.00% | 4.00% |
Other postretirement benefit plans | Special situations | ||
Assets Fair Value | ||
Plan assets | $ 4 | $ 4 |
Target plan asset allocations | 1.00% | 1.00% |
Actual plan asset allocations | 0.00% | 0.00% |
Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | $ 29 | $ 25 |
Target plan asset allocations | 3.00% | 3.00% |
Actual plan asset allocations | 2.00% | 2.00% |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | ||
Assets Fair Value | ||
Plan assets | $ 6,410 | $ 6,436 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 2,852 | 2,220 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 2,660 | 2,360 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Mortgage- and asset-backed securities | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 356 | 1,317 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 542 | 539 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | 214 | 221 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 113 | 95 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | 71 | 69 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 15 | 42 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Trust-owned life insurance | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 15 | 15 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Significant Other Observable Inputs (Level 2) | Pension plans | ||
Assets Fair Value | ||
Plan assets | 6,154 | 5,157 |
Significant Other Observable Inputs (Level 2) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 1,247 | 898 |
Significant Other Observable Inputs (Level 2) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 1,497 | 1,286 |
Significant Other Observable Inputs (Level 2) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 951 | 965 |
Significant Other Observable Inputs (Level 2) | Pension plans | Mortgage- and asset-backed securities | ||
Assets Fair Value | ||
Plan assets | 9 | 9 |
Significant Other Observable Inputs (Level 2) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 1,673 | 1,315 |
Significant Other Observable Inputs (Level 2) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 772 | 684 |
Significant Other Observable Inputs (Level 2) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 5 | 0 |
Significant Other Observable Inputs (Level 2) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Significant Other Observable Inputs (Level 2) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Significant Other Observable Inputs (Level 2) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | 870 | 772 |
Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 98 | 81 |
Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | 102 | 80 |
Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 32 | 31 |
Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 44 | 35 |
Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 86 | 82 |
Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Trust-owned life insurance | ||
Assets Fair Value | ||
Plan assets | 508 | 463 |
Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Net Asset Value as a Practical Expedient (NAV) | Pension plans | ||
Assets Fair Value | ||
Plan assets | 2,866 | 2,526 |
Net Asset Value as a Practical Expedient (NAV) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Net Asset Value as a Practical Expedient (NAV) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Net Asset Value as a Practical Expedient (NAV) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Net Asset Value as a Practical Expedient (NAV) | Pension plans | Mortgage- and asset-backed securities | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Net Asset Value as a Practical Expedient (NAV) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Net Asset Value as a Practical Expedient (NAV) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Net Asset Value as a Practical Expedient (NAV) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Net Asset Value as a Practical Expedient (NAV) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 1,596 | 1,418 |
Net Asset Value as a Practical Expedient (NAV) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 166 | 155 |
Net Asset Value as a Practical Expedient (NAV) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 1,104 | 953 |
Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | 75 | 67 |
Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Trust-owned life insurance | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 42 | 38 |
Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 4 | 4 |
Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 29 | 25 |
Alabama Power | Pension plans | ||
Assets Fair Value | ||
Plan assets | $ 3,699 | $ 3,372 |
Target plan asset allocations | 100.00% | 100.00% |
Actual plan asset allocations | 100.00% | 100.00% |
Alabama Power | Pension plans | Equity | ||
Assets Fair Value | ||
Target plan asset allocations | 51.00% | 51.00% |
Actual plan asset allocations | 56.00% | 51.00% |
Alabama Power | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | $ 984 | $ 744 |
Alabama Power | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | $ 997 | $ 871 |
Alabama Power | Pension plans | Fixed income | ||
Assets Fair Value | ||
Target plan asset allocations | 23.00% | 23.00% |
Actual plan asset allocations | 23.00% | 29.00% |
Alabama Power | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | $ 228 | $ 230 |
Alabama Power | Pension plans | Mortgage- and asset-backed securities | ||
Assets Fair Value | ||
Plan assets | 2 | 2 |
Alabama Power | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 401 | 314 |
Alabama Power | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 185 | 163 |
Alabama Power | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 86 | 315 |
Alabama Power | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | $ 512 | $ 468 |
Target plan asset allocations | 14.00% | 14.00% |
Actual plan asset allocations | 13.00% | 12.00% |
Alabama Power | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | $ 40 | $ 37 |
Target plan asset allocations | 3.00% | 3.00% |
Actual plan asset allocations | 1.00% | 1.00% |
Alabama Power | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | $ 264 | $ 228 |
Target plan asset allocations | 9.00% | 9.00% |
Actual plan asset allocations | 7.00% | 7.00% |
Alabama Power | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | $ 459 | $ 412 |
Target plan asset allocations | 100.00% | 100.00% |
Actual plan asset allocations | 100.00% | 100.00% |
Alabama Power | Other postretirement benefit plans | Equity | ||
Assets Fair Value | ||
Target plan asset allocations | 68.00% | 68.00% |
Actual plan asset allocations | 69.00% | 67.00% |
Alabama Power | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | $ 37 | $ 34 |
Alabama Power | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | $ 36 | $ 32 |
Alabama Power | Other postretirement benefit plans | Fixed income | ||
Assets Fair Value | ||
Target plan asset allocations | 24.00% | 24.00% |
Actual plan asset allocations | 25.00% | 27.00% |
Alabama Power | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | $ 11 | $ 10 |
Alabama Power | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 14 | 11 |
Alabama Power | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 7 | 6 |
Alabama Power | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 5 | 12 |
Alabama Power | Other postretirement benefit plans | Trust-owned life insurance | ||
Assets Fair Value | ||
Plan assets | 321 | 281 |
Alabama Power | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | $ 18 | $ 17 |
Target plan asset allocations | 4.00% | 4.00% |
Actual plan asset allocations | 4.00% | 4.00% |
Alabama Power | Other postretirement benefit plans | Special situations | ||
Assets Fair Value | ||
Plan assets | $ 1 | $ 1 |
Target plan asset allocations | 1.00% | 1.00% |
Actual plan asset allocations | 0.00% | 0.00% |
Alabama Power | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | $ 9 | $ 8 |
Target plan asset allocations | 3.00% | 3.00% |
Actual plan asset allocations | 2.00% | 2.00% |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | ||
Assets Fair Value | ||
Plan assets | $ 1,538 | $ 1,538 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 685 | 530 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 638 | 564 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Mortgage- and asset-backed securities | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 85 | 315 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 130 | 129 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | 59 | 64 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 26 | 26 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | 23 | 21 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 5 | 12 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Trust-owned life insurance | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 5 | 5 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Pension plans | ||
Assets Fair Value | ||
Plan assets | 1,475 | 1,230 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 299 | 214 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 359 | 307 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 228 | 230 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Pension plans | Mortgage- and asset-backed securities | ||
Assets Fair Value | ||
Plan assets | 2 | 2 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 401 | 314 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 185 | 163 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 1 | 0 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | 377 | 327 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 11 | 8 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | 13 | 11 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 11 | 10 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 14 | 11 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 7 | 6 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Trust-owned life insurance | ||
Assets Fair Value | ||
Plan assets | 321 | 281 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | ||
Assets Fair Value | ||
Plan assets | 686 | 604 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Mortgage- and asset-backed securities | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 382 | 339 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 40 | 37 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 264 | 228 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | 23 | 21 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Trust-owned life insurance | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 13 | 12 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 1 | 1 |
Alabama Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 9 | 8 |
Georgia Power | Pension plans | ||
Assets Fair Value | ||
Plan assets | $ 4,864 | $ 4,461 |
Target plan asset allocations | 100.00% | 100.00% |
Actual plan asset allocations | 100.00% | 100.00% |
Georgia Power | Pension plans | Equity | ||
Assets Fair Value | ||
Target plan asset allocations | 51.00% | 51.00% |
Actual plan asset allocations | 56.00% | 51.00% |
Georgia Power | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | $ 1,292 | $ 985 |
Georgia Power | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | $ 1,311 | $ 1,153 |
Georgia Power | Pension plans | Fixed income | ||
Assets Fair Value | ||
Target plan asset allocations | 23.00% | 23.00% |
Actual plan asset allocations | 23.00% | 29.00% |
Georgia Power | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | $ 300 | $ 305 |
Georgia Power | Pension plans | Mortgage- and asset-backed securities | ||
Assets Fair Value | ||
Plan assets | 3 | 3 |
Georgia Power | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 527 | 415 |
Georgia Power | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 243 | 216 |
Georgia Power | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 113 | 416 |
Georgia Power | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | $ 674 | $ 618 |
Target plan asset allocations | 14.00% | 14.00% |
Actual plan asset allocations | 13.00% | 12.00% |
Georgia Power | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | $ 53 | $ 49 |
Target plan asset allocations | 3.00% | 3.00% |
Actual plan asset allocations | 1.00% | 1.00% |
Georgia Power | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | $ 348 | $ 301 |
Target plan asset allocations | 9.00% | 9.00% |
Actual plan asset allocations | 7.00% | 7.00% |
Georgia Power | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | $ 427 | $ 402 |
Target plan asset allocations | 100.00% | 100.00% |
Actual plan asset allocations | 100.00% | 100.00% |
Georgia Power | Other postretirement benefit plans | Equity | ||
Assets Fair Value | ||
Target plan asset allocations | 60.00% | 60.00% |
Actual plan asset allocations | 64.00% | 61.00% |
Georgia Power | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | $ 68 | $ 55 |
Georgia Power | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | $ 71 | $ 61 |
Georgia Power | Other postretirement benefit plans | Fixed income | ||
Assets Fair Value | ||
Target plan asset allocations | 33.00% | 33.00% |
Actual plan asset allocations | 30.00% | 34.00% |
Georgia Power | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | $ 8 | $ 7 |
Georgia Power | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 13 | 11 |
Georgia Power | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 46 | 45 |
Georgia Power | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 5 | 16 |
Georgia Power | Other postretirement benefit plans | Trust-owned life insurance | ||
Assets Fair Value | ||
Plan assets | 188 | 182 |
Georgia Power | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | $ 18 | $ 16 |
Target plan asset allocations | 4.00% | 4.00% |
Actual plan asset allocations | 4.00% | 3.00% |
Georgia Power | Other postretirement benefit plans | Special situations | ||
Assets Fair Value | ||
Plan assets | $ 1 | $ 1 |
Target plan asset allocations | 1.00% | 1.00% |
Actual plan asset allocations | 0.00% | 0.00% |
Georgia Power | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | $ 9 | $ 8 |
Target plan asset allocations | 2.00% | 2.00% |
Actual plan asset allocations | 2.00% | 2.00% |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | ||
Assets Fair Value | ||
Plan assets | $ 2,021 | $ 2,033 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 899 | 701 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 839 | 746 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Mortgage- and asset-backed securities | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 112 | 416 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 171 | 170 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | 89 | 94 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 58 | 48 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | 21 | 25 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 5 | 16 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Trust-owned life insurance | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 5 | 5 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Pension plans | ||
Assets Fair Value | ||
Plan assets | 1,939 | 1,630 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 393 | 284 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 472 | 407 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 300 | 305 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Pension plans | Mortgage- and asset-backed securities | ||
Assets Fair Value | ||
Plan assets | 3 | 3 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 527 | 415 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 243 | 216 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 1 | 0 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | 315 | 288 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 10 | 7 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | 50 | 36 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 8 | 7 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 13 | 11 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 46 | 45 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Trust-owned life insurance | ||
Assets Fair Value | ||
Plan assets | 188 | 182 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | ||
Assets Fair Value | ||
Plan assets | 904 | 798 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Mortgage- and asset-backed securities | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 503 | 448 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 53 | 49 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 348 | 301 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | 23 | 20 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Trust-owned life insurance | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 13 | 11 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 1 | 1 |
Georgia Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 9 | 8 |
Mississippi Power | Pension plans | ||
Assets Fair Value | ||
Plan assets | $ 704 | $ 644 |
Target plan asset allocations | 100.00% | 100.00% |
Actual plan asset allocations | 100.00% | 100.00% |
Mississippi Power | Pension plans | Equity | ||
Assets Fair Value | ||
Target plan asset allocations | 51.00% | 51.00% |
Actual plan asset allocations | 56.00% | 51.00% |
Mississippi Power | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | $ 188 | $ 142 |
Mississippi Power | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | $ 190 | $ 167 |
Mississippi Power | Pension plans | Fixed income | ||
Assets Fair Value | ||
Target plan asset allocations | 23.00% | 23.00% |
Actual plan asset allocations | 23.00% | 29.00% |
Mississippi Power | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | $ 43 | $ 44 |
Mississippi Power | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 76 | 60 |
Mississippi Power | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 35 | 31 |
Mississippi Power | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 16 | 60 |
Mississippi Power | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | $ 98 | $ 90 |
Target plan asset allocations | 14.00% | 14.00% |
Actual plan asset allocations | 13.00% | 12.00% |
Mississippi Power | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | $ 8 | $ 7 |
Target plan asset allocations | 3.00% | 3.00% |
Actual plan asset allocations | 1.00% | 1.00% |
Mississippi Power | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | $ 50 | $ 43 |
Target plan asset allocations | 9.00% | 9.00% |
Actual plan asset allocations | 7.00% | 7.00% |
Mississippi Power | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | $ 26 | $ 25 |
Target plan asset allocations | 100.00% | 100.00% |
Actual plan asset allocations | 100.00% | 100.00% |
Mississippi Power | Other postretirement benefit plans | Equity | ||
Assets Fair Value | ||
Target plan asset allocations | 43.00% | 43.00% |
Actual plan asset allocations | 46.00% | 41.00% |
Mississippi Power | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | $ 6 | $ 4 |
Mississippi Power | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | $ 6 | $ 6 |
Mississippi Power | Other postretirement benefit plans | Fixed income | ||
Assets Fair Value | ||
Target plan asset allocations | 37.00% | 37.00% |
Actual plan asset allocations | 36.00% | 42.00% |
Mississippi Power | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | $ 5 | $ 6 |
Mississippi Power | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 2 | 2 |
Mississippi Power | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 1 | 1 |
Mississippi Power | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 1 | 2 |
Mississippi Power | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | $ 3 | $ 3 |
Target plan asset allocations | 11.00% | 11.00% |
Actual plan asset allocations | 11.00% | 10.00% |
Mississippi Power | Other postretirement benefit plans | Special situations | ||
Assets Fair Value | ||
Plan assets | $ 0 | $ 0 |
Target plan asset allocations | 2.00% | 2.00% |
Actual plan asset allocations | 1.00% | 1.00% |
Mississippi Power | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | $ 2 | $ 1 |
Target plan asset allocations | 7.00% | 7.00% |
Actual plan asset allocations | 6.00% | 6.00% |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | ||
Assets Fair Value | ||
Plan assets | $ 294 | $ 294 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 131 | 101 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 122 | 108 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 16 | 60 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 25 | 25 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | 10 | 10 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 4 | 3 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | 4 | 4 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 1 | 2 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 1 | 1 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Pension plans | ||
Assets Fair Value | ||
Plan assets | 279 | 235 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 57 | 41 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 68 | 59 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 43 | 44 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 76 | 60 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 35 | 31 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | 12 | 12 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 2 | 1 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | 2 | 2 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 5 | 6 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 2 | 2 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 1 | 1 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | ||
Assets Fair Value | ||
Plan assets | 131 | 115 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 73 | 65 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 8 | 7 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 50 | 43 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | 4 | 3 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 2 | 2 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Mississippi Power | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 2 | 1 |
Southern Power | Pension plans | ||
Assets Fair Value | ||
Plan assets | $ 187 | $ 170 |
Target plan asset allocations | 100.00% | 100.00% |
Actual plan asset allocations | 100.00% | 100.00% |
Southern Power | Pension plans | Equity | ||
Assets Fair Value | ||
Target plan asset allocations | 51.00% | 51.00% |
Actual plan asset allocations | 56.00% | 51.00% |
Southern Power | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | $ 50 | $ 38 |
Southern Power | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | $ 51 | $ 44 |
Southern Power | Pension plans | Fixed income | ||
Assets Fair Value | ||
Target plan asset allocations | 23.00% | 23.00% |
Actual plan asset allocations | 23.00% | 29.00% |
Southern Power | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | $ 12 | $ 12 |
Southern Power | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 20 | 16 |
Southern Power | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 9 | 8 |
Southern Power | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 4 | 16 |
Southern Power | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | $ 26 | $ 23 |
Target plan asset allocations | 14.00% | 14.00% |
Actual plan asset allocations | 13.00% | 12.00% |
Southern Power | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | $ 2 | $ 2 |
Target plan asset allocations | 3.00% | 3.00% |
Actual plan asset allocations | 1.00% | 1.00% |
Southern Power | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | $ 13 | $ 11 |
Target plan asset allocations | 9.00% | 9.00% |
Actual plan asset allocations | 7.00% | 7.00% |
Southern Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | ||
Assets Fair Value | ||
Plan assets | $ 78 | $ 77 |
Southern Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 35 | 27 |
Southern Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 32 | 28 |
Southern Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 4 | 16 |
Southern Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 7 | 6 |
Southern Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Power | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Power | Significant Other Observable Inputs (Level 2) | Pension plans | ||
Assets Fair Value | ||
Plan assets | 75 | 63 |
Southern Power | Significant Other Observable Inputs (Level 2) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 15 | 11 |
Southern Power | Significant Other Observable Inputs (Level 2) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 19 | 16 |
Southern Power | Significant Other Observable Inputs (Level 2) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 12 | 12 |
Southern Power | Significant Other Observable Inputs (Level 2) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 20 | 16 |
Southern Power | Significant Other Observable Inputs (Level 2) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 9 | 8 |
Southern Power | Significant Other Observable Inputs (Level 2) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Power | Significant Other Observable Inputs (Level 2) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Power | Significant Other Observable Inputs (Level 2) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Power | Significant Other Observable Inputs (Level 2) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | ||
Assets Fair Value | ||
Plan assets | 34 | 30 |
Southern Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 19 | 17 |
Southern Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 2 | 2 |
Southern Power | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 13 | 11 |
Southern Company Gas | Pension plans | ||
Assets Fair Value | ||
Plan assets | $ 1,128 | $ 1,054 |
Target plan asset allocations | 100.00% | 100.00% |
Actual plan asset allocations | 100.00% | 100.00% |
Southern Company Gas | Pension plans | Equity | ||
Assets Fair Value | ||
Target plan asset allocations | 51.00% | 51.00% |
Actual plan asset allocations | 56.00% | 51.00% |
Southern Company Gas | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | $ 300 | $ 233 |
Southern Company Gas | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | $ 304 | $ 272 |
Southern Company Gas | Pension plans | Fixed income | ||
Assets Fair Value | ||
Target plan asset allocations | 23.00% | 23.00% |
Actual plan asset allocations | 23.00% | 29.00% |
Southern Company Gas | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | $ 69 | $ 72 |
Southern Company Gas | Pension plans | Mortgage- and asset-backed securities | ||
Assets Fair Value | ||
Plan assets | 1 | 1 |
Southern Company Gas | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 122 | 98 |
Southern Company Gas | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 56 | 51 |
Southern Company Gas | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 26 | 98 |
Southern Company Gas | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | $ 157 | $ 146 |
Target plan asset allocations | 14.00% | 14.00% |
Actual plan asset allocations | 13.00% | 12.00% |
Southern Company Gas | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | $ 12 | $ 12 |
Target plan asset allocations | 3.00% | 3.00% |
Actual plan asset allocations | 1.00% | 1.00% |
Southern Company Gas | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | $ 81 | $ 71 |
Target plan asset allocations | 9.00% | 9.00% |
Actual plan asset allocations | 7.00% | 7.00% |
Southern Company Gas | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | $ 125 | $ 114 |
Target plan asset allocations | 100.00% | 100.00% |
Actual plan asset allocations | 100.00% | 100.00% |
Southern Company Gas | Other postretirement benefit plans | Equity | ||
Assets Fair Value | ||
Target plan asset allocations | 72.00% | 72.00% |
Actual plan asset allocations | 76.00% | 73.00% |
Southern Company Gas | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | $ 68 | $ 60 |
Southern Company Gas | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | $ 27 | $ 23 |
Southern Company Gas | Other postretirement benefit plans | Fixed income | ||
Assets Fair Value | ||
Target plan asset allocations | 26.00% | 26.00% |
Actual plan asset allocations | 22.00% | 25.00% |
Southern Company Gas | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | $ 1 | $ 1 |
Southern Company Gas | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 1 | 1 |
Southern Company Gas | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 25 | 25 |
Southern Company Gas | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 1 | 2 |
Southern Company Gas | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | $ 1 | $ 1 |
Target plan asset allocations | 1.00% | 1.00% |
Actual plan asset allocations | 1.00% | 1.00% |
Southern Company Gas | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | $ 1 | $ 1 |
Target plan asset allocations | 1.00% | 1.00% |
Actual plan asset allocations | 1.00% | 1.00% |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | ||
Assets Fair Value | ||
Plan assets | $ 470 | $ 480 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 209 | 166 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 195 | 176 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Mortgage- and asset-backed securities | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 26 | 98 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 40 | 40 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | 5 | 6 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 2 | 2 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | 2 | 2 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 1 | 2 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Pension plans | ||
Assets Fair Value | ||
Plan assets | 448 | 385 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 91 | 67 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 109 | 96 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 69 | 72 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Pension plans | Mortgage- and asset-backed securities | ||
Assets Fair Value | ||
Plan assets | 1 | 1 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 122 | 98 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 56 | 51 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | 118 | 106 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 66 | 58 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | 25 | 21 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 1 | 1 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 1 | 1 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 25 | 25 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Significant Other Observable Inputs (Level 2) | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Pension plans | ||
Assets Fair Value | ||
Plan assets | 210 | 189 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Pension plans | International equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Pension plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Mortgage- and asset-backed securities | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 117 | 106 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Special situations | ||
Assets Fair Value | ||
Plan assets | 12 | 12 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Pension plans | Private equity | ||
Assets Fair Value | ||
Plan assets | 81 | 71 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | ||
Assets Fair Value | ||
Plan assets | 2 | 2 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Domestic equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | International equity | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | U.S. Treasury, government, and agency bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Corporate bonds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Pooled funds | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Cash equivalents and other | ||
Assets Fair Value | ||
Plan assets | 0 | 0 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Real estate investments | ||
Assets Fair Value | ||
Plan assets | 1 | 1 |
Southern Company Gas | Net Asset Value as a Practical Expedient (NAV) | Other postretirement benefit plans | Private equity | ||
Assets Fair Value | ||
Plan assets | $ 1 | $ 1 |
RETIREMENT BENEFITS - 401K Plan
RETIREMENT BENEFITS - 401K Plan Matching Contributions (Details) - Employee Savings Plan - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Defined Benefit Plan Disclosure [Line Items] | |||
Defined contribution plan, cost | $ 120 | $ 113 | $ 119 |
Alabama Power | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Defined contribution plan, cost | 26 | 25 | 24 |
Georgia Power | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Defined contribution plan, cost | 29 | 27 | 26 |
Mississippi Power | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Defined contribution plan, cost | 5 | 4 | 5 |
Southern Power | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Defined contribution plan, cost | 2 | 2 | 3 |
Southern Company Gas | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Defined contribution plan, cost | $ 16 | $ 15 | $ 18 |
STOCK COMPENSATION - Schedule o
STOCK COMPENSATION - Schedule of Employees Participating in Stock-Based Compensation Programs (Details) | Dec. 31, 2020employee |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Number of employees | 1,958 |
Alabama Power | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Number of employees | 263 |
Georgia Power | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Number of employees | 295 |
Mississippi Power | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Number of employees | 86 |
Southern Power | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Number of employees | 46 |
Southern Company Gas | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Number of employees | 204 |
STOCK COMPENSATION - Performanc
STOCK COMPENSATION - Performance Shares Narrative (Details) $ / shares in Units, $ in Millions | 1 Months Ended | 12 Months Ended | |||
Feb. 28, 2021$ / sharesshares | Feb. 29, 2020$ / sharesshares | Dec. 31, 2020USD ($)type$ / sharesshares | Dec. 31, 2019$ / sharesshares | Dec. 31, 2018$ / shares | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
Shares converted (in shares) | 1,800,000 | ||||
Shares converted (in dollars per share) | $ / shares | $ 68.59 | ||||
Subsequent Event | |||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
Shares converted (in shares) | 2,500,000 | ||||
Shares converted (in dollars per share) | $ / shares | $ 60.10 | ||||
Performance Shares | |||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
Vesting period of performance share units issued under performance share plan | 3 years | 3 years | |||
Minimum percentage of transfer performance shares to common stock based on actual total shareholder return | 0.00% | ||||
Maximum percentage of transfer performance shares to common stock based on actual total shareholder return | 200.00% | ||||
Number of types of PSUs | type | 3 | ||||
Performance share units, unvested (in shares) | 2,200,000 | 2,500,000 | |||
Equity instrument, granted (in shares) | 1,200,000 | ||||
Equity instruments, vested (in shares) | 1,500,000 | ||||
Unrecognized compensation cost | $ | $ 32 | ||||
Total unrecognized compensation cost related to award, weighted average period | 19 months | ||||
EPS-based and ROE-based Performance Share Units | |||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
Vesting period of performance share units issued under performance share plan | 3 years | ||||
Equity instrument granted in period, weighted average grant date fair value (in dollars per share) | $ / shares | $ 68.42 | $ 49.38 | $ 43.49 |
STOCK COMPENSATION - Performa_2
STOCK COMPENSATION - Performance Shares, Assumptions Used (Details) - Performance Shares - $ / shares | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Expected volatility | 15.40% | 15.60% | 14.90% |
Expected term (in years) | 3 years | 3 years | 3 years |
Interest rate | 1.40% | 2.40% | 2.40% |
Weighted average grant-date fair value (in dollars per share) | $ 77.65 | $ 62.71 | $ 43.75 |
STOCK COMPENSATION - Performa_3
STOCK COMPENSATION - Performance Shares, Compensation Costs and Related Tax Benefit (Details) - Performance Shares - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Compensation cost recognized in income | $ 84 | $ 77 | $ 91 |
Tax benefit of compensation cost recognized in income | 22 | 20 | 24 |
Southern Company Gas | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Compensation cost recognized in income | 13 | 14 | 11 |
Tax benefit of compensation cost recognized in income | $ 4 | $ 4 | $ 3 |
STOCK COMPENSATION - Restricted
STOCK COMPENSATION - Restricted Stock Units Narrative (Details) - Restricted Stock Units (RSUs) - USD ($) $ / shares in Units, shares in Millions, $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Equity instrument granted in period, weighted average grant date fair value (in dollars per share) | $ 67.60 | $ 50.44 | $ 43.81 |
Award requisite service period | 3 years | ||
Total unrecognized compensation cost related to award, weighted average period | 18 months | ||
Restricted stock units, unvested (in shares) | 1.2 | 1.3 | |
Equity instrument, granted (in shares) | 0.5 | ||
Vested or forfeited (in shares) | 0.6 | ||
Total compensation cost for award recognized in income | $ 29 | $ 28 | $ 27 |
Total compensation cost for award recognized in income, tax benefit | 8 | $ 7 | $ 7 |
Total unrecognized compensation cost related to award | $ 11 | ||
One-year vesting period | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Total unrecognized compensation cost related to award, weighted average period | 1 year | ||
Two-year vesting period | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Total unrecognized compensation cost related to award, weighted average period | 2 years | ||
Three-year vesting period | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Total unrecognized compensation cost related to award, weighted average period | 3 years |
STOCK COMPENSATION - Stock Opti
STOCK COMPENSATION - Stock Options Narrative (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Cash received from issuance related to option exercise | $ 66 | $ 482 | $ 41 |
Stock Options | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Weighted average remaining contractual term for options outstanding | 2 years | ||
Stock Options | Maximum | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Expiration period | 10 years |
STOCK COMPENSATION - Stock Op_2
STOCK COMPENSATION - Stock Option Activity (Details) shares in Millions | 12 Months Ended |
Dec. 31, 2020$ / sharesshares | |
Shares Subject to Option | |
Beginning balance (in shares) | shares | 5.9 |
Exercised (in shares) | shares | 1.6 |
Ending balance (in shares) | shares | 4.3 |
Weighted Average Exercise Price | |
Beginning balance (in dollars per share) | $ / shares | $ 42.52 |
Exercised (in dollars per share) | $ / shares | 41.13 |
Ending balance (in dollars per share) | $ / shares | $ 43.04 |
STOCK COMPENSATION - Aggregate
STOCK COMPENSATION - Aggregate Intrinsic Value for Options Exercised (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Aggregate intrinsic value for options outstanding | $ 78 | ||
Aggregate intrinsic value for options exercisable | 78 | ||
Intrinsic value of options exercised | 38 | $ 167 | $ 9 |
Tax benefit of options exercised | 9 | 35 | 2 |
Alabama Power | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Aggregate intrinsic value for options outstanding | 8 | ||
Aggregate intrinsic value for options exercisable | 8 | ||
Intrinsic value of options exercised | 5 | 21 | 2 |
Tax benefit of options exercised | 1 | 4 | 0 |
Georgia Power | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Aggregate intrinsic value for options outstanding | 25 | ||
Aggregate intrinsic value for options exercisable | 25 | ||
Intrinsic value of options exercised | 9 | 30 | 2 |
Tax benefit of options exercised | 2 | $ 6 | $ 0 |
Southern Company Gas | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Aggregate intrinsic value for options outstanding | 6 | ||
Aggregate intrinsic value for options exercisable | $ 6 |
FAIR VALUE MEASUREMENTS - Asset
FAIR VALUE MEASUREMENTS - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Assets: | ||
Derivative asset | $ 281 | $ 233 |
Liabilities: | ||
Derivative liability | 64 | 189 |
Weather derivative premium | 6 | 4 |
Collateral already posted, aggregate fair value | 28 | 99 |
Recurring | ||
Assets: | ||
Cash equivalents | 584 | 1,395 |
Other investments | 33 | 30 |
Total | 3,759 | 4,189 |
Liabilities: | ||
Contingent consideration | 17 | 19 |
Total | 637 | 770 |
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Cash equivalents | 575 | 1,393 |
Other investments | 9 | 9 |
Total | 1,974 | 2,650 |
Liabilities: | ||
Contingent consideration | 0 | 0 |
Total | 389 | 442 |
Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Cash equivalents | 9 | 2 |
Other investments | 24 | 21 |
Total | 1,677 | 1,461 |
Liabilities: | ||
Contingent consideration | 0 | 0 |
Total | 227 | 302 |
Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Cash equivalents | 0 | 0 |
Other investments | 0 | 0 |
Total | 32 | 22 |
Liabilities: | ||
Contingent consideration | 17 | 19 |
Total | 21 | 26 |
Recurring | Fair Value Measured at Net Asset Value Per Share (NAV) | ||
Assets: | ||
Total | 76 | 56 |
Alabama Power | ||
Assets: | ||
Derivative asset | 5 | 2 |
Liabilities: | ||
Derivative liability | 0 | 22 |
Alabama Power | Recurring | ||
Assets: | ||
Cash equivalents | 320 | 693 |
Other investments | 24 | 21 |
Total | 1,512 | 1,739 |
Alabama Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Cash equivalents | 311 | 691 |
Other investments | 0 | 0 |
Total | 959 | 1,273 |
Alabama Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Cash equivalents | 9 | 2 |
Other investments | 24 | 21 |
Total | 477 | 410 |
Alabama Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Cash equivalents | 0 | 0 |
Other investments | 0 | 0 |
Total | 0 | 0 |
Alabama Power | Recurring | Fair Value Measured at Net Asset Value Per Share (NAV) | ||
Assets: | ||
Total | 76 | 56 |
Georgia Power | ||
Assets: | ||
Derivative asset | 3 | 1 |
Liabilities: | ||
Derivative liability | 1 | 67 |
Georgia Power | Recurring | ||
Assets: | ||
Total | 1,160 | 1,017 |
Liabilities: | ||
Total | 70 | |
Georgia Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Total | 340 | 276 |
Liabilities: | ||
Total | 0 | |
Georgia Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Total | 820 | 741 |
Liabilities: | ||
Total | 70 | |
Georgia Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Total | 0 | 0 |
Liabilities: | ||
Total | 0 | |
Mississippi Power | ||
Assets: | ||
Derivative asset | 2 | 0 |
Liabilities: | ||
Derivative liability | 2 | 26 |
Mississippi Power | Recurring | ||
Assets: | ||
Cash equivalents | 21 | 281 |
Total | 30 | 282 |
Mississippi Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Cash equivalents | 21 | 281 |
Total | 21 | 281 |
Mississippi Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Cash equivalents | 0 | 0 |
Total | 9 | 1 |
Mississippi Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Cash equivalents | 0 | 0 |
Total | 0 | 0 |
Southern Power | ||
Assets: | ||
Derivative asset | 89 | 19 |
Liabilities: | ||
Derivative liability | 26 | 27 |
Southern Power | Recurring | ||
Assets: | ||
Cash equivalents | 113 | |
Total | 89 | 132 |
Liabilities: | ||
Contingent consideration | 17 | 19 |
Total | 43 | 46 |
Southern Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Cash equivalents | 113 | |
Total | 0 | 113 |
Liabilities: | ||
Contingent consideration | 0 | 0 |
Total | 0 | 0 |
Southern Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Cash equivalents | 0 | |
Total | 89 | 19 |
Liabilities: | ||
Contingent consideration | 0 | 0 |
Total | 26 | 27 |
Southern Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Cash equivalents | 0 | |
Total | 0 | 0 |
Liabilities: | ||
Contingent consideration | 17 | 19 |
Total | 17 | 19 |
Southern Company Gas | ||
Assets: | ||
Derivative asset | 162 | 212 |
Liabilities: | ||
Derivative liability | 35 | 41 |
Collateral already posted, aggregate fair value | 28 | 99 |
Southern Company Gas | Recurring | ||
Assets: | ||
Cash equivalents | 8 | |
Total | 696 | 708 |
Southern Company Gas | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Cash equivalents | 8 | |
Total | 402 | 397 |
Southern Company Gas | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Cash equivalents | 0 | |
Total | 262 | 289 |
Southern Company Gas | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Cash equivalents | 0 | |
Total | 32 | 22 |
Energy-related derivatives | Recurring | ||
Assets: | ||
Derivative asset | 704 | 677 |
Liabilities: | ||
Derivative liability | 597 | 703 |
Energy-related derivatives | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Derivative asset | 401 | 388 |
Liabilities: | ||
Derivative liability | 389 | 442 |
Energy-related derivatives | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Derivative asset | 271 | 267 |
Liabilities: | ||
Derivative liability | 204 | 254 |
Energy-related derivatives | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Derivative asset | 32 | 22 |
Liabilities: | ||
Derivative liability | 4 | 7 |
Energy-related derivatives | Alabama Power | Recurring | ||
Assets: | ||
Derivative asset | 12 | 4 |
Liabilities: | ||
Derivative liability | 7 | 24 |
Energy-related derivatives | Alabama Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Derivative asset | 0 | 0 |
Liabilities: | ||
Derivative liability | 0 | 0 |
Energy-related derivatives | Alabama Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Derivative asset | 12 | 4 |
Liabilities: | ||
Derivative liability | 7 | 24 |
Energy-related derivatives | Alabama Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Derivative asset | 0 | 0 |
Liabilities: | ||
Derivative liability | 0 | 0 |
Energy-related derivatives | Georgia Power | Recurring | ||
Assets: | ||
Derivative asset | 15 | 4 |
Liabilities: | ||
Derivative liability | 13 | 53 |
Energy-related derivatives | Georgia Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Derivative asset | 0 | 0 |
Liabilities: | ||
Derivative liability | 0 | 0 |
Energy-related derivatives | Georgia Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Derivative asset | 15 | 4 |
Liabilities: | ||
Derivative liability | 13 | 53 |
Energy-related derivatives | Georgia Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Derivative asset | 0 | 0 |
Liabilities: | ||
Derivative liability | 0 | 0 |
Energy-related derivatives | Mississippi Power | Recurring | ||
Assets: | ||
Derivative asset | 9 | 1 |
Liabilities: | ||
Derivative liability | 9 | 27 |
Energy-related derivatives | Mississippi Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Derivative asset | 0 | 0 |
Liabilities: | ||
Derivative liability | 0 | 0 |
Energy-related derivatives | Mississippi Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Derivative asset | 9 | 1 |
Liabilities: | ||
Derivative liability | 9 | 27 |
Energy-related derivatives | Mississippi Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Derivative asset | 0 | 0 |
Liabilities: | ||
Derivative liability | 0 | 0 |
Energy-related derivatives | Southern Power | Recurring | ||
Assets: | ||
Derivative asset | 2 | 3 |
Liabilities: | ||
Derivative liability | 3 | 3 |
Energy-related derivatives | Southern Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Derivative asset | 0 | 0 |
Liabilities: | ||
Derivative liability | 0 | 0 |
Energy-related derivatives | Southern Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Derivative asset | 2 | 3 |
Liabilities: | ||
Derivative liability | 3 | 3 |
Energy-related derivatives | Southern Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Derivative asset | 0 | 0 |
Liabilities: | ||
Derivative liability | 0 | 0 |
Energy-related derivatives | Southern Company Gas | Recurring | ||
Assets: | ||
Derivative asset | 666 | 665 |
Liabilities: | ||
Derivative liability | 565 | 596 |
Energy-related derivatives | Southern Company Gas | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Derivative asset | 401 | 388 |
Liabilities: | ||
Derivative liability | 389 | 442 |
Energy-related derivatives | Southern Company Gas | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Derivative asset | 233 | 255 |
Liabilities: | ||
Derivative liability | 172 | 147 |
Energy-related derivatives | Southern Company Gas | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Derivative asset | 32 | 22 |
Liabilities: | ||
Derivative liability | 4 | 7 |
Interest rate derivatives | Recurring | ||
Assets: | ||
Derivative asset | 20 | 2 |
Liabilities: | ||
Derivative liability | 24 | |
Interest rate derivatives | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Derivative asset | 0 | 0 |
Liabilities: | ||
Derivative liability | 0 | |
Interest rate derivatives | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Derivative asset | 20 | 2 |
Liabilities: | ||
Derivative liability | 24 | |
Interest rate derivatives | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Derivative asset | 0 | 0 |
Liabilities: | ||
Derivative liability | 0 | |
Interest rate derivatives | Georgia Power | Recurring | ||
Liabilities: | ||
Derivative liability | 17 | |
Interest rate derivatives | Georgia Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Liabilities: | ||
Derivative liability | 0 | |
Interest rate derivatives | Georgia Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Liabilities: | ||
Derivative liability | 17 | |
Interest rate derivatives | Georgia Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Liabilities: | ||
Derivative liability | 0 | |
Interest rate derivatives | Southern Company Gas | Recurring | ||
Assets: | ||
Derivative asset | 2 | |
Interest rate derivatives | Southern Company Gas | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Derivative asset | 0 | |
Interest rate derivatives | Southern Company Gas | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Derivative asset | 2 | |
Interest rate derivatives | Southern Company Gas | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Derivative asset | 0 | |
Foreign currency derivatives | Recurring | ||
Assets: | ||
Derivative asset | 87 | 16 |
Liabilities: | ||
Derivative liability | 23 | 24 |
Foreign currency derivatives | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Derivative asset | 0 | 0 |
Liabilities: | ||
Derivative liability | 0 | 0 |
Foreign currency derivatives | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Derivative asset | 87 | 16 |
Liabilities: | ||
Derivative liability | 23 | 24 |
Foreign currency derivatives | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Derivative asset | 0 | 0 |
Liabilities: | ||
Derivative liability | 0 | 0 |
Foreign currency derivatives | Southern Power | Recurring | ||
Assets: | ||
Derivative asset | 87 | 16 |
Liabilities: | ||
Derivative liability | 23 | 24 |
Foreign currency derivatives | Southern Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Derivative asset | 0 | 0 |
Liabilities: | ||
Derivative liability | 0 | 0 |
Foreign currency derivatives | Southern Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Derivative asset | 87 | 16 |
Liabilities: | ||
Derivative liability | 23 | 24 |
Foreign currency derivatives | Southern Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Derivative asset | 0 | 0 |
Liabilities: | ||
Derivative liability | 0 | 0 |
Domestic equity | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 1,013 | 886 |
Domestic equity | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 862 | 751 |
Domestic equity | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 151 | 135 |
Domestic equity | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Domestic equity | Alabama Power | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 684 | 611 |
Domestic equity | Alabama Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 543 | 488 |
Domestic equity | Alabama Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 141 | 123 |
Domestic equity | Alabama Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Domestic equity | Georgia Power | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 320 | 264 |
Domestic equity | Georgia Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 319 | 263 |
Domestic equity | Georgia Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 1 | 1 |
Domestic equity | Georgia Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Domestic equity | Southern Company Gas | Recurring | ||
Assets: | ||
Non-qualified deferred compensation trusts | 9 | 11 |
Domestic equity | Southern Company Gas | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Non-qualified deferred compensation trusts | 0 | 0 |
Domestic equity | Southern Company Gas | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Non-qualified deferred compensation trusts | 9 | 11 |
Domestic equity | Southern Company Gas | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Non-qualified deferred compensation trusts | 0 | 0 |
Foreign equity | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 338 | 288 |
Foreign equity | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 85 | 68 |
Foreign equity | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 253 | 220 |
Foreign equity | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Foreign equity | Alabama Power | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 158 | 132 |
Foreign equity | Alabama Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 85 | 68 |
Foreign equity | Alabama Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 73 | 64 |
Foreign equity | Alabama Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Foreign equity | Georgia Power | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 177 | 152 |
Foreign equity | Georgia Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Foreign equity | Georgia Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 177 | 152 |
Foreign equity | Georgia Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Foreign equity | Southern Company Gas | Recurring | ||
Assets: | ||
Non-qualified deferred compensation trusts | 3 | 4 |
Foreign equity | Southern Company Gas | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Non-qualified deferred compensation trusts | 0 | 0 |
Foreign equity | Southern Company Gas | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Non-qualified deferred compensation trusts | 3 | 4 |
Foreign equity | Southern Company Gas | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Non-qualified deferred compensation trusts | 0 | 0 |
U.S. Treasury and government agency securities | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 284 | 307 |
U.S. Treasury and government agency securities | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
U.S. Treasury and government agency securities | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 284 | 307 |
U.S. Treasury and government agency securities | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
U.S. Treasury and government agency securities | Alabama Power | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 21 | 21 |
U.S. Treasury and government agency securities | Alabama Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
U.S. Treasury and government agency securities | Alabama Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 21 | 21 |
U.S. Treasury and government agency securities | Alabama Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
U.S. Treasury and government agency securities | Georgia Power | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 263 | 286 |
U.S. Treasury and government agency securities | Georgia Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
U.S. Treasury and government agency securities | Georgia Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 263 | 286 |
U.S. Treasury and government agency securities | Georgia Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Municipal bonds | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 85 | 85 |
Municipal bonds | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Municipal bonds | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 85 | 85 |
Municipal bonds | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Municipal bonds | Alabama Power | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 1 | 1 |
Municipal bonds | Alabama Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Municipal bonds | Alabama Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 1 | 1 |
Municipal bonds | Alabama Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Municipal bonds | Georgia Power | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 84 | 84 |
Municipal bonds | Georgia Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Municipal bonds | Georgia Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 84 | 84 |
Municipal bonds | Georgia Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Pooled funds – fixed income | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 17 | 17 |
Pooled funds – fixed income | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Pooled funds – fixed income | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 17 | 17 |
Pooled funds – fixed income | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Pooled funds – fixed income | Southern Company Gas | Recurring | ||
Assets: | ||
Non-qualified deferred compensation trusts | 17 | 17 |
Pooled funds – fixed income | Southern Company Gas | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Non-qualified deferred compensation trusts | 0 | 0 |
Pooled funds – fixed income | Southern Company Gas | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Non-qualified deferred compensation trusts | 17 | 17 |
Pooled funds – fixed income | Southern Company Gas | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Non-qualified deferred compensation trusts | 0 | 0 |
Corporate bonds | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 399 | 320 |
Corporate bonds | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 13 | 23 |
Corporate bonds | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 386 | 297 |
Corporate bonds | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Corporate bonds | Alabama Power | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 180 | 167 |
Corporate bonds | Alabama Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 13 | 23 |
Corporate bonds | Alabama Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 167 | 144 |
Corporate bonds | Alabama Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Corporate bonds | Georgia Power | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 219 | 153 |
Corporate bonds | Georgia Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Corporate bonds | Georgia Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 219 | 153 |
Corporate bonds | Georgia Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Mortgage and asset backed securities | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 83 | 87 |
Mortgage and asset backed securities | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Mortgage and asset backed securities | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 83 | 87 |
Mortgage and asset backed securities | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Mortgage and asset backed securities | Alabama Power | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 29 | 29 |
Mortgage and asset backed securities | Alabama Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Mortgage and asset backed securities | Alabama Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 29 | 29 |
Mortgage and asset backed securities | Alabama Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Mortgage and asset backed securities | Georgia Power | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 54 | 57 |
Mortgage and asset backed securities | Georgia Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Mortgage and asset backed securities | Georgia Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 54 | 57 |
Mortgage and asset backed securities | Georgia Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Private equity | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 76 | 56 |
Private equity | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Private equity | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Private equity | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Private equity | Recurring | Fair Value Measured at Net Asset Value Per Share (NAV) | ||
Assets: | ||
Nuclear decommissioning trusts | 76 | 56 |
Private equity | Alabama Power | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 76 | 56 |
Private equity | Alabama Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Private equity | Alabama Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Private equity | Alabama Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Private equity | Alabama Power | Recurring | Fair Value Measured at Net Asset Value Per Share (NAV) | ||
Assets: | ||
Nuclear decommissioning trusts | 76 | 56 |
Cash and cash equivalents | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 1 | 1 |
Cash and cash equivalents | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 1 | 1 |
Cash and cash equivalents | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Cash and cash equivalents | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Cash equivalents | Southern Company Gas | Recurring | ||
Assets: | ||
Non-qualified deferred compensation trusts | 1 | 1 |
Cash equivalents | Southern Company Gas | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Non-qualified deferred compensation trusts | 1 | 1 |
Cash equivalents | Southern Company Gas | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Non-qualified deferred compensation trusts | 0 | 0 |
Cash equivalents | Southern Company Gas | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Non-qualified deferred compensation trusts | 0 | 0 |
Other | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 35 | 22 |
Other | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 28 | 17 |
Other | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 7 | 5 |
Other | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Other | Alabama Power | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 7 | 4 |
Other | Alabama Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 7 | 3 |
Other | Alabama Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 1 |
Other | Alabama Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | 0 | 0 |
Other | Georgia Power | Recurring | ||
Assets: | ||
Nuclear decommissioning trusts | 28 | 17 |
Other | Georgia Power | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets: | ||
Nuclear decommissioning trusts | 21 | 13 |
Other | Georgia Power | Recurring | Significant Other Observable Inputs (Level 2) | ||
Assets: | ||
Nuclear decommissioning trusts | 7 | 4 |
Other | Georgia Power | Recurring | Significant Unobservable Inputs (Level 3) | ||
Assets: | ||
Nuclear decommissioning trusts | $ 0 | $ 0 |
FAIR VALUE MEASUREMENTS - Narra
FAIR VALUE MEASUREMENTS - Narrative (Details) $ in Millions | Dec. 31, 2020USD ($)$ / MMBTU | Dec. 31, 2019USD ($) |
Private equity | Alabama Power | ||
Fair Value, Option, Quantitative Disclosures [Line Items] | ||
Alternative investment | $ 76 | $ 56 |
Unfunded commitments | 73 | $ 70 |
Energy-related derivatives | Significant Unobservable Inputs (Level 3) | Southern Company Gas | ||
Fair Value, Option, Quantitative Disclosures [Line Items] | ||
Derivative assets, at fair value, net | $ 28 | |
Minimum | Measurement Input, Commodity Forward Price | Valuation, Market Approach | Energy-related derivatives | Significant Unobservable Inputs (Level 3) | Southern Company Gas | ||
Fair Value, Option, Quantitative Disclosures [Line Items] | ||
Derivative asset net, measurement input | $ / MMBTU | (0.08) | |
Maximum | Measurement Input, Commodity Forward Price | Valuation, Market Approach | Energy-related derivatives | Significant Unobservable Inputs (Level 3) | Southern Company Gas | ||
Fair Value, Option, Quantitative Disclosures [Line Items] | ||
Derivative asset net, measurement input | $ / MMBTU | 0.24 |
FAIR VALUE MEASUREMENTS - Finan
FAIR VALUE MEASUREMENTS - Financial Instruments, Carrying Amount Not Equal to Fair Value (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Carrying Amount | $ 48,349 | $ 44,561 |
Fair Value | 56,264 | 48,339 |
Alabama Power | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Carrying Amount | 8,864 | 8,517 |
Fair Value | 10,702 | 9,525 |
Georgia Power | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Carrying Amount | 12,825 | 11,660 |
Fair Value | 15,198 | 12,680 |
Mississippi Power | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Carrying Amount | 1,400 | 1,589 |
Fair Value | 1,590 | 1,671 |
Southern Power | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Carrying Amount | 3,692 | 4,398 |
Fair Value | 4,165 | 4,708 |
Southern Company Gas | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Carrying Amount | 6,626 | 5,845 |
Fair Value | $ 7,973 | $ 6,509 |
FAIR VALUE MEASUREMENTS - Fair
FAIR VALUE MEASUREMENTS - Fair Value of Commodity Derivative Contracts that Include a Significant Unobservable Component (Details) - Southern Company Gas $ in Millions | 12 Months Ended |
Dec. 31, 2020USD ($) | |
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] | |
Beginning balance | $ 14 |
Transfers to Level 3 | 70 |
Transfers from Level 3 | (34) |
Instruments realized or otherwise settled during period | (16) |
Changes in fair value | (6) |
Ending balance | $ 28 |
DERIVATIVES - Energy-Related De
DERIVATIVES - Energy-Related Derivative Contracts (Details) - Energy-related, Natural Gas MMBTU in Millions | Dec. 31, 2020MMBTU |
Derivative [Line Items] | |
Net Purchased mmBtu | 835 |
Alabama Power | |
Derivative [Line Items] | |
Net Purchased mmBtu | 78 |
Georgia Power | |
Derivative [Line Items] | |
Net Purchased mmBtu | 135 |
Mississippi Power | |
Derivative [Line Items] | |
Net Purchased mmBtu | 89 |
Southern Power | |
Derivative [Line Items] | |
Net Purchased mmBtu | 10 |
Southern Company Gas | |
Derivative [Line Items] | |
Net Purchased mmBtu | 523 |
Long | Not Designated as Hedging Instrument | Southern Company Gas | |
Derivative [Line Items] | |
Derivative nonmonetary notional amount net long short position volume | 4,421 |
Short | Not Designated as Hedging Instrument | Southern Company Gas | |
Derivative [Line Items] | |
Derivative nonmonetary notional amount net long short position volume | 3,898 |
DERIVATIVES - Narrative (Detail
DERIVATIVES - Narrative (Details) MWh in Millions, MMBTU in Millions | 12 Months Ended | |
Dec. 31, 2020USD ($)MWhMMBTU | Dec. 31, 2019USD ($) | |
Derivative [Line Items] | ||
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | 29 | |
Estimated pre-tax gains (losses) that will be reclassified from OCI to interest expense for the next 12-month period | $ | $ (25,000,000) | |
Collateral already posted, aggregate fair value | $ | $ 28,000,000 | $ 99,000,000 |
Southern Power | ||
Derivative [Line Items] | ||
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | 9 | |
Southern Power | Public Utilities, Inventory, Power Position | ||
Derivative [Line Items] | ||
Net Purchased mmBtu | MWh | 1 | |
Alabama Power | ||
Derivative [Line Items] | ||
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | 7 | |
Georgia Power | ||
Derivative [Line Items] | ||
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | 9 | |
Mississippi Power | ||
Derivative [Line Items] | ||
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | 4 | |
Parent Company and Southern Power | ||
Derivative [Line Items] | ||
Foreign currency cash flow hedge gain (loss) to be reclassified during next 12 months | $ | $ 10,000,000 | |
Registrants | Derivative Counterparties | ||
Derivative [Line Items] | ||
Collateral already posted, aggregate fair value | $ | $ 0 |
DERIVATIVES - Interest Rate Der
DERIVATIVES - Interest Rate Derivatives (Details) - Interest rate derivatives $ in Millions | 12 Months Ended |
Dec. 31, 2020USD ($) | |
Derivative [Line Items] | |
Notional Amount | $ 1,560 |
Fair Value Gain (Loss) December 31, 2020 | 20 |
Mississippi Power | Cash Flow Hedges of Existing Debt | |
Derivative [Line Items] | |
Notional Amount | $ 60 |
Weighted Average Interest Rate Paid | 0.58% |
Fair Value Gain (Loss) December 31, 2020 | $ 0 |
Southern Company | Fair Value Hedges of Existing Debt | |
Derivative [Line Items] | |
Notional Amount | $ 1,500 |
Interest Rate Received | 2.35% |
Weighted Average Interest Rate Paid | 0.87% |
Fair Value Gain (Loss) December 31, 2020 | $ 20 |
DERIVATIVES - Foreign Currency
DERIVATIVES - Foreign Currency Derivatives (Details) € in Millions, $ in Millions | 12 Months Ended | ||
Dec. 31, 2020USD ($) | Dec. 31, 2020EUR (€) | Dec. 31, 2019USD ($) | |
Foreign currency derivatives | Cash Flow Hedges of Existing Debt | |||
Derivative [Line Items] | |||
Pay Notional | $ 1,241 | ||
Receive Notional | € | € 1,100 | ||
Fair Value Gain (Loss) December 31, 2020 | 65 | ||
Southern Power | |||
Derivative [Line Items] | |||
Receive Notional | 1,100 | ||
Fair Value Gain (Loss) December 31, 2020 | 109 | $ (5) | |
Southern Power | Foreign currency derivatives | June 2022 | Cash Flow Hedges of Existing Debt | |||
Derivative [Line Items] | |||
Pay Notional | $ 677 | ||
Pay Rate | 2.95% | ||
Receive Notional | € | 600 | ||
Receive Rate | 1.00% | ||
Fair Value Gain (Loss) December 31, 2020 | $ 40 | ||
Southern Power | Foreign currency derivatives | June 2026 | Cash Flow Hedges of Existing Debt | |||
Derivative [Line Items] | |||
Pay Notional | $ 564 | ||
Pay Rate | 3.78% | ||
Receive Notional | € | € 500 | ||
Receive Rate | 1.85% | ||
Fair Value Gain (Loss) December 31, 2020 | $ 25 |
DERIVATIVES - Derivative Financ
DERIVATIVES - Derivative Financial Statement Presentation and Amounts With Balance Sheet Offsetting (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | $ 810 | $ 696 |
Derivative asset, gross amount offset | (529) | (463) |
Derivative asset, net amounts recognized in the balance sheets | 281 | 233 |
Derivative liability, gross amounts recognized | 621 | 751 |
Derivative liability, gross amounts offset | (557) | (562) |
Derivative liability, gross amounts recognized in balance sheets | 64 | 189 |
Collateral already posted, aggregate fair value | 28 | 99 |
Not Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 658 | 668 |
Derivative liability, gross amounts recognized | 563 | 583 |
Energy-related derivatives | Other deferred charges and assets | Not Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 270 | 207 |
Energy-related derivatives | Other deferred credits and liabilities | Not Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 232 | 225 |
Energy-related derivatives | Assets from risk management activities | Not Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 388 | 461 |
Energy-related derivatives | Liabilities from risk management activities | Not Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 331 | 358 |
Alabama Power | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 12 | 4 |
Derivative asset, gross amount offset | (7) | (2) |
Derivative asset, net amounts recognized in the balance sheets | 5 | 2 |
Derivative liability, gross amounts recognized | 7 | 24 |
Derivative liability, gross amounts offset | (7) | (2) |
Derivative liability, gross amounts recognized in balance sheets | 0 | 22 |
Georgia Power | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 15 | 4 |
Derivative asset, gross amount offset | (12) | (3) |
Derivative asset, net amounts recognized in the balance sheets | 3 | 1 |
Derivative liability, gross amounts recognized | 13 | 70 |
Derivative liability, gross amounts offset | (12) | (3) |
Derivative liability, gross amounts recognized in balance sheets | 1 | 67 |
Mississippi Power | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 9 | 1 |
Derivative asset, gross amount offset | (7) | (1) |
Derivative asset, net amounts recognized in the balance sheets | 2 | 0 |
Derivative liability, gross amounts recognized | 9 | 27 |
Derivative liability, gross amounts offset | (7) | (1) |
Derivative liability, gross amounts recognized in balance sheets | 2 | 26 |
Southern Power | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, net amounts recognized in the balance sheets | 89 | 19 |
Derivative liability, gross amounts recognized in balance sheets | 26 | 27 |
Southern Power | Energy-related derivatives | Other current assets | Not Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 0 | 2 |
Southern Power | Energy-related derivatives | Other current liabilities | Not Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 1 | 1 |
Southern Company Gas | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 665 | 668 |
Derivative asset, gross amount offset | (503) | (456) |
Derivative asset, net amounts recognized in the balance sheets | 162 | 212 |
Derivative liability, gross amounts recognized | 566 | 596 |
Derivative liability, gross amounts offset | (531) | (555) |
Derivative liability, gross amounts recognized in balance sheets | 35 | 41 |
Collateral already posted, aggregate fair value | 28 | 99 |
Southern Company Gas | Not Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 658 | 666 |
Derivative liability, gross amounts recognized | 562 | 582 |
Southern Company Gas | Energy-related derivatives | Other current liabilities | Not Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 330 | 357 |
Southern Company Gas | Energy-related derivatives | Other deferred charges and assets | Not Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 270 | 207 |
Southern Company Gas | Energy-related derivatives | Other deferred credits and liabilities | Not Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 232 | 225 |
Southern Company Gas | Energy-related derivatives | Assets from risk management activities | Not Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 388 | 459 |
Hedging Instruments for Regulatory Purposes | Energy-related derivatives | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 42 | 9 |
Derivative liability, gross amounts recognized | 30 | 114 |
Hedging Instruments for Regulatory Purposes | Energy-related derivatives | Other deferred charges and assets | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 18 | 6 |
Hedging Instruments for Regulatory Purposes | Energy-related derivatives | Other deferred credits and liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 19 | 44 |
Hedging Instruments for Regulatory Purposes | Energy-related derivatives | Assets from risk management activities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 24 | 3 |
Hedging Instruments for Regulatory Purposes | Energy-related derivatives | Liabilities from risk management activities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 11 | 70 |
Hedging Instruments for Regulatory Purposes | Alabama Power | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 12 | 4 |
Derivative liability, gross amounts recognized | 7 | 24 |
Hedging Instruments for Regulatory Purposes | Alabama Power | Energy-related derivatives | Other current assets | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 7 | 2 |
Hedging Instruments for Regulatory Purposes | Alabama Power | Energy-related derivatives | Other current liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 2 | 14 |
Hedging Instruments for Regulatory Purposes | Alabama Power | Energy-related derivatives | Other deferred charges and assets | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 5 | 2 |
Hedging Instruments for Regulatory Purposes | Alabama Power | Energy-related derivatives | Other deferred credits and liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 5 | 10 |
Hedging Instruments for Regulatory Purposes | Georgia Power | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 15 | 4 |
Derivative liability, gross amounts recognized | 13 | 53 |
Hedging Instruments for Regulatory Purposes | Georgia Power | Energy-related derivatives | Other current assets | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 7 | 1 |
Hedging Instruments for Regulatory Purposes | Georgia Power | Energy-related derivatives | Other current liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 5 | 32 |
Hedging Instruments for Regulatory Purposes | Georgia Power | Energy-related derivatives | Other deferred charges and assets | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 8 | 3 |
Hedging Instruments for Regulatory Purposes | Georgia Power | Energy-related derivatives | Other deferred credits and liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 8 | 21 |
Hedging Instruments for Regulatory Purposes | Mississippi Power | Energy-related derivatives | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 9 | 1 |
Derivative liability, gross amounts recognized | 9 | 27 |
Hedging Instruments for Regulatory Purposes | Mississippi Power | Energy-related derivatives | Other current assets | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 4 | 0 |
Hedging Instruments for Regulatory Purposes | Mississippi Power | Energy-related derivatives | Other current liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 3 | 15 |
Hedging Instruments for Regulatory Purposes | Mississippi Power | Energy-related derivatives | Other deferred charges and assets | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 5 | 1 |
Hedging Instruments for Regulatory Purposes | Mississippi Power | Energy-related derivatives | Other deferred credits and liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 6 | 12 |
Hedging Instruments for Regulatory Purposes | Southern Company Gas | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 6 | 0 |
Derivative liability, gross amounts recognized | 1 | 10 |
Hedging Instruments for Regulatory Purposes | Southern Company Gas | Energy-related derivatives | Other current liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 1 | 9 |
Hedging Instruments for Regulatory Purposes | Southern Company Gas | Energy-related derivatives | Other deferred charges and assets | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 0 | 0 |
Hedging Instruments for Regulatory Purposes | Southern Company Gas | Energy-related derivatives | Other deferred credits and liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 0 | 1 |
Hedging Instruments for Regulatory Purposes | Southern Company Gas | Energy-related derivatives | Assets from risk management activities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 6 | 0 |
Cash Flow and Fair Value Hedging | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 110 | 19 |
Derivative liability, gross amounts recognized | 28 | 54 |
Cash Flow and Fair Value Hedging | Energy-related derivatives | Assets from risk management activities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 3 | 1 |
Cash Flow and Fair Value Hedging | Energy-related derivatives | Liabilities from risk management activities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 5 | 6 |
Cash Flow and Fair Value Hedging | Interest rate derivatives | Other deferred charges and assets | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 0 | 0 |
Cash Flow and Fair Value Hedging | Interest rate derivatives | Other deferred credits and liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 0 | 1 |
Cash Flow and Fair Value Hedging | Interest rate derivatives | Assets from risk management activities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 20 | 2 |
Cash Flow and Fair Value Hedging | Interest rate derivatives | Liabilities from risk management activities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 0 | 23 |
Cash Flow and Fair Value Hedging | Foreign currency derivatives | Other deferred charges and assets | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 87 | 16 |
Cash Flow and Fair Value Hedging | Foreign currency derivatives | Other deferred credits and liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 0 | 0 |
Cash Flow and Fair Value Hedging | Foreign currency derivatives | Assets from risk management activities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 0 | 0 |
Cash Flow and Fair Value Hedging | Foreign currency derivatives | Liabilities from risk management activities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 23 | 24 |
Cash Flow and Fair Value Hedging | Georgia Power | Interest rate derivatives | Other current assets | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 0 | 0 |
Cash Flow and Fair Value Hedging | Georgia Power | Interest rate derivatives | Other current liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 0 | 17 |
Cash Flow and Fair Value Hedging | Southern Power | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 89 | 17 |
Derivative liability, gross amounts recognized | 25 | 26 |
Cash Flow and Fair Value Hedging | Southern Power | Energy-related derivatives | Other current assets | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 2 | 1 |
Cash Flow and Fair Value Hedging | Southern Power | Energy-related derivatives | Other current liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 2 | 2 |
Cash Flow and Fair Value Hedging | Southern Power | Foreign currency derivatives | Other current assets | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 0 | 0 |
Cash Flow and Fair Value Hedging | Southern Power | Foreign currency derivatives | Other current liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 23 | 24 |
Cash Flow and Fair Value Hedging | Southern Power | Foreign currency derivatives | Other deferred charges and assets | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 87 | 16 |
Cash Flow and Fair Value Hedging | Southern Power | Foreign currency derivatives | Other deferred credits and liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 0 | 0 |
Cash Flow and Fair Value Hedging | Southern Company Gas | Energy-related derivatives | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 1 | 2 |
Derivative liability, gross amounts recognized | 3 | 4 |
Cash Flow and Fair Value Hedging | Southern Company Gas | Energy-related derivatives | Other current liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 3 | 4 |
Cash Flow and Fair Value Hedging | Southern Company Gas | Energy-related derivatives | Assets from risk management activities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | 1 | 0 |
Cash Flow and Fair Value Hedging | Southern Company Gas | Interest rate derivatives | Other current liabilities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative liability, gross amounts recognized | 0 | 0 |
Cash Flow and Fair Value Hedging | Southern Company Gas | Interest rate derivatives | Assets from risk management activities | Designated as Hedging Instrument | ||
Fair value of energy-related derivatives and interest rate derivatives | ||
Derivative asset, gross amounts recognized | $ 0 | $ 2 |
DERIVATIVES - Schedule of Unrea
DERIVATIVES - Schedule of Unrealized Gain (Loss) Recognized in the Balance Sheet (Details) - Energy-related derivatives - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | $ 12 | $ (94) |
Other regulatory assets, current | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | (63) | |
Other regulatory assets, deferred | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | (2) | (37) |
Other regulatory liabilities, current | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | 12 | 6 |
Other regulatory liabilities, deferred | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | 2 | |
Alabama Power | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | 6 | (20) |
Alabama Power | Other regulatory assets, current | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | (14) | |
Alabama Power | Other regulatory assets, deferred | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | 0 | (8) |
Alabama Power | Other regulatory liabilities, current | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | 5 | 2 |
Alabama Power | Other regulatory liabilities, deferred | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | 1 | |
Georgia Power | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | 2 | (49) |
Georgia Power | Other regulatory assets, current | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | (31) | |
Georgia Power | Other regulatory assets, deferred | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | (1) | (18) |
Georgia Power | Other regulatory liabilities, current | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | 2 | 0 |
Georgia Power | Other regulatory liabilities, deferred | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | 1 | |
Mississippi Power | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | 0 | (26) |
Mississippi Power | Other regulatory assets, current | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | (15) | |
Mississippi Power | Other regulatory assets, deferred | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | (1) | (11) |
Mississippi Power | Other regulatory liabilities, current | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | 1 | 0 |
Mississippi Power | Other regulatory liabilities, deferred | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | 0 | |
Southern Company Gas | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | 4 | 1 |
Southern Company Gas | Other regulatory assets, current | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | (3) | |
Southern Company Gas | Other regulatory assets, deferred | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | 0 | 0 |
Southern Company Gas | Other regulatory liabilities, current | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | 4 | $ 4 |
Southern Company Gas | Other regulatory liabilities, deferred | ||
Derivatives, Fair Value [Line Items] | ||
Total energy-related derivative gains (losses) | $ 0 |
DERIVATIVES - Pre-Tax Effects o
DERIVATIVES - Pre-Tax Effects of Derivatives Designated as Cash Flow Hedging on AOCI (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | $ 14 | $ (154) | $ (62) |
Energy-related derivatives | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | (8) | (13) | 17 |
Interest rate derivatives | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | (26) | (57) | (1) |
Foreign currency derivatives | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | 48 | (84) | (78) |
Georgia Power | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | (3) | (59) | 0 |
Southern Power | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | 46 | (88) | (68) |
Southern Power | Energy-related derivatives | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | (2) | (4) | 10 |
Southern Power | Foreign currency derivatives | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | 48 | (84) | (78) |
Southern Company Gas | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | (29) | (7) | 7 |
Southern Company Gas | Energy-related derivatives | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | (6) | (9) | 7 |
Southern Company Gas | Interest rate derivatives | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | $ (23) | $ 2 | $ 0 |
DERIVATIVES - Pre-Tax Effects_2
DERIVATIVES - Pre-Tax Effects of Derivatives Designated as Cash Flow and Fair Value Hedging on Income (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Derivative Instruments, Gain (Loss) [Line Items] | |||
Depreciation and amortization | $ 3,518 | $ 3,038 | $ 3,131 |
Interest expense, net of amounts capitalized | (1,821) | (1,736) | (1,842) |
Other income (expense), net | 336 | 252 | 114 |
Energy-related derivatives | Cost of Sales | Cash Flow Hedging | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | (8) | (2) | 2 |
Energy-related derivatives | Depreciation and Amortization | Cash Flow Hedging | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | (3) | (6) | 7 |
Interest rate derivatives | Interest Expense | Cash Flow Hedging | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | (26) | (20) | (21) |
Interest rate derivatives | Interest Expense | Fair Value Hedging | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | 27 | 42 | (12) |
Foreign currency derivatives | Interest Expense | Cash Flow Hedging | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | (23) | (24) | (24) |
Foreign currency derivatives | Other Income (Expense) | Cash Flow Hedging | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | 114 | (24) | (60) |
Southern Power | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Depreciation and amortization | 494 | 479 | 493 |
Interest expense, net of amounts capitalized | (151) | (169) | (183) |
Other income (expense), net | 19 | 47 | 23 |
Southern Power | Energy-related derivatives | Depreciation and Amortization | Cash Flow Hedging | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | (3) | (6) | 7 |
Southern Power | Foreign currency derivatives | Interest Expense | Cash Flow Hedging | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | (23) | (24) | (24) |
Southern Power | Foreign currency derivatives | Other Income (Expense) | Cash Flow Hedging | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Gain (Loss) Recognized in OCI on Derivative | $ 114 | $ (24) | $ (60) |
DERIVATIVES - Cumulative Basis
DERIVATIVES - Cumulative Basis Adjustments for Fair Value Hedges (Details) - Fair Value Hedging - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Securities due within one year | ||
Derivative Instruments, Gain (Loss) [Line Items] | ||
Carrying Amount of the Hedged Item | $ (1,509) | $ (599) |
Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item | (10) | 0 |
Long-term debt | ||
Derivative Instruments, Gain (Loss) [Line Items] | ||
Carrying Amount of the Hedged Item | 0 | (1,494) |
Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item | $ 0 | $ 3 |
DERIVATIVES - Pre-Tax Effects_3
DERIVATIVES - Pre-Tax Effects of Derivatives Not Designated as Hedging (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Derivative Instruments, Gain (Loss) [Line Items] | |||
Derivative instruments not designated as hedging instruments, gain (loss), net | $ 149 | $ 233 | $ (128) |
Energy-related derivatives | Natural Gas Revenues | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Derivative instruments not designated as hedging instruments, gain (loss), net | 134 | 223 | (122) |
Energy-related derivatives | Cost of Natural Gas | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Derivative instruments not designated as hedging instruments, gain (loss), net | 15 | 10 | (6) |
Weather Derivatives | |||
Derivative Instruments, Gain (Loss) [Line Items] | |||
Derivative, gain (loss) on derivative, net | $ 9 | $ 3 | $ 5 |
ACQUISITIONS AND DISPOSITIONS -
ACQUISITIONS AND DISPOSITIONS - Southern Company Narrative (Details) - USD ($) | 1 Months Ended | 3 Months Ended | 12 Months Ended | |||||||
Dec. 31, 2019 | Jan. 31, 2019 | Dec. 31, 2020 | Sep. 30, 2019 | Jun. 30, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 30, 2019 | Jul. 31, 2019 | |
Business Acquisition [Line Items] | ||||||||||
Gain (loss) on dispositions | $ 66,000,000 | $ 2,588,000,000 | $ 301,000,000 | |||||||
Impairment charges | $ 0 | |||||||||
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Gulf Power | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Cash proceeds from sale of business | $ 5,800,000,000 | |||||||||
Indebtedness assumed | 1,300,000,000 | |||||||||
Gain (loss) on dispositions | 2,600,000,000 | 2,600,000,000 | ||||||||
Gain (loss) on dispositions, after tax | $ 1,400,000,000 | 1,400,000,000 | ||||||||
Disposal Group, Disposed of by Sale, Not Discontinued Operations | PowerSecure Utility Infrastructure Services Unit | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Consideration for sale | $ 65,000,000 | |||||||||
Disposal Group, Disposed of by Sale, Not Discontinued Operations | PowerSecure International, Inc. Lighting Business | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Cash proceeds from sale of business | $ 4,000,000 | |||||||||
Indebtedness assumed | 5,000,000 | 5,000,000 | ||||||||
Gain (loss) on dispositions | (58,000,000) | |||||||||
Gain (loss) on dispositions, after tax | (52,000,000) | |||||||||
Consideration for sale | $ 9,000,000 | $ 9,000,000 | ||||||||
Disposal Group, Held-for-sale, Not Discontinued Operations | PowerSecure Utility Infrastructure Services Unit | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Impairment charges | $ 32,000,000 | |||||||||
Disposal Group, Held-for-sale, Not Discontinued Operations | PowerSecure International, Inc. Lighting Business | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Impairment charges | $ 2,000,000 | |||||||||
Goodwill and intangible asset impairment | $ 18,000,000 | |||||||||
Disposal Group, Held-for-sale, Not Discontinued Operations | Leveraged Lease Investment | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Consideration for sale | $ 20,000,000 |
ACQUISITIONS AND DISPOSITIONS_2
ACQUISITIONS AND DISPOSITIONS - Alabama Power Narrative (Details) - Alabama Power - Autauga Combined Cycle $ in Millions | Aug. 31, 2020USD ($)MW |
Business Acquisition [Line Items] | |
Approximate nameplate capacity (in MW) | MW | 885 |
Purchase price | $ 461 |
Property, plant, and equipment | $ 452 |
Power sales agreement, remaining term | 3 years |
ACQUISITIONS AND DISPOSITIONS_3
ACQUISITIONS AND DISPOSITIONS - Schedule of Acquisitions (Details) - Southern Power - MW | 1 Months Ended | 12 Months Ended | |||
May 31, 2020 | Mar. 31, 2018 | Dec. 31, 2020 | Dec. 31, 2019 | Mar. 31, 2020 | |
Business Acquisition [Line Items] | |||||
Approximate Nameplate Capacity (MW) | 300 | ||||
Beech Ridge II | |||||
Business Acquisition [Line Items] | |||||
Approximate Nameplate Capacity (MW) | 56 | ||||
PPA Contract Period | 12 years | ||||
DSGP | |||||
Business Acquisition [Line Items] | |||||
Approximate Nameplate Capacity (MW) | 28 | ||||
PPA Contract Period | 15 years | ||||
Noncontrolling interest, approximate nameplate capacity (in MW) | 10 | ||||
Approximate nameplate capacity, repowered amount (in MW) | 18 | ||||
Gaskell West 1 | |||||
Business Acquisition [Line Items] | |||||
Approximate Nameplate Capacity (MW) | 20 | ||||
PPA Contract Period | 20 years | ||||
Beech Ridge II | Beech Ridge II | |||||
Business Acquisition [Line Items] | |||||
Ownership Percentage | 100.00% | ||||
DSGP | DSGP | |||||
Business Acquisition [Line Items] | |||||
Ownership Percentage | 100.00% | ||||
Gaskell West 1 | Gaskell West 1 | |||||
Business Acquisition [Line Items] | |||||
Ownership Percentage | 100.00% |
ACQUISITIONS AND DISPOSITIONS_4
ACQUISITIONS AND DISPOSITIONS - Southern Power Narrative (Details) $ in Millions | Jan. 17, 2020USD ($) | Jun. 30, 2019USD ($)MW | Dec. 31, 2018USD ($)investorwind_farm | May 31, 2018USD ($) | Jun. 30, 2018USD ($) | Dec. 31, 2021 | Dec. 31, 2020USD ($)agreement | Dec. 31, 2019USD ($) | Dec. 31, 2018USD ($)investorwind_farmoperating_facility | Mar. 31, 2020MW | May 31, 2019MW |
Business Acquisition [Line Items] | |||||||||||
Construction work in progress | $ 8,697 | $ 7,880 | |||||||||
Impairment charges | 0 | 168 | $ 210 | ||||||||
(Gain) loss on dispositions, net | 65 | 2,569 | 291 | ||||||||
Sale of noncontrolling interests | 65 | 1,273 | |||||||||
Purchase of membership interests from noncontrolling interests | 60 | ||||||||||
Gain (loss) on dispositions | $ 66 | 2,588 | 301 | ||||||||
Southern Power | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Approximate nameplate capacity (in MW) | MW | 300 | ||||||||||
Number of Power Purchase Agreements | agreement | 2 | ||||||||||
Construction work in progress | $ 127 | 515 | |||||||||
Impairment charges | 0 | 3 | 156 | ||||||||
(Gain) loss on dispositions, net | 39 | 23 | 2 | ||||||||
Sale of noncontrolling interests | 65 | $ 1,273 | |||||||||
Purchase of membership interests from noncontrolling interests | 60 | ||||||||||
Number of wind facilities | operating_facility | 8 | ||||||||||
Gain (loss) on dispositions | 39 | 24 | $ 3 | ||||||||
Southern Power | Series of Business Acquisitions | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Construction work in progress | 34 | ||||||||||
Southern Power | Minimum | Series of Business Acquisitions | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Aggregate construction costs | 392 | ||||||||||
Southern Power | Maximum | Series of Business Acquisitions | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Aggregate construction costs | $ 460 | ||||||||||
SP Solar Holdings I, LP | Southern Power | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Sale of equity interest in limited partnership | 33.00% | ||||||||||
SP Wind | Southern Power | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Sale of equity interest in limited partnership | 100.00% | ||||||||||
Wind Generating Facility | Southern Power | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Project qualification for production tax credits, percentage | 100.00% | ||||||||||
Impairment charges | $ 36 | ||||||||||
(Gain) loss on dispositions, net | $ 0 | $ 17 | |||||||||
Scenario, Forecast | Wind Generating Facility | Southern Power | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Project qualification for production tax credits, percentage | 80.00% | ||||||||||
SP Solar Holdings I, LP | Southern Power | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Distribution made to limited partner, cash distributions paid, percentage | 67.00% | ||||||||||
SP Solar Holdings I, LP | SP Solar Holdings I, LP | Southern Power | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Sale of equity interest in limited partnership | 33.00% | ||||||||||
Proceeds from sale of equity method investments | $ 1,200 | ||||||||||
Sale of noncontrolling interests | 511 | ||||||||||
SP Wind | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Number of wind facilities | wind_farm | 8 | 8 | |||||||||
SP Wind | Southern Power | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Number of financial investors | investor | 3 | ||||||||||
Distribution made to limited partner, cash distributions paid, percentage | 60.00% | ||||||||||
SP Wind | Financial Investors | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Distribution made to limited partner, cash distributions paid, percentage | 40.00% | 40.00% | |||||||||
Allocation of tax attributes to limited partner | 99.00% | ||||||||||
SP Wind | SP Wind | Southern Power | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Proceeds from sale of equity method investments | $ 1,200 | ||||||||||
Number of financial investors | investor | 3 | ||||||||||
Common stockholders' equity | Southern Power | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Sale of noncontrolling interests | $ (2) | $ (417) | |||||||||
Purchase of membership interests from noncontrolling interests | $ 410 | $ (5) | |||||||||
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Florida Plants | Southern Power | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Cash proceeds from sale of business | $ 203 | ||||||||||
Asset impairment charge | $ 119 | ||||||||||
Asset impairment charge, after tax | $ 89 | ||||||||||
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Nacogdoches Biomass-Fueled Facility | Southern Power | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Approximate nameplate capacity (in MW) | MW | 115 | ||||||||||
Consideration for sale | $ 461 | ||||||||||
Gain (loss) on dispositions | 23 | ||||||||||
Gain (loss) on dispositions, after tax | $ 88 | ||||||||||
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Mankato | Southern Power | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Approximate nameplate capacity (in MW) | MW | 385 | ||||||||||
Consideration for sale | $ 663 | ||||||||||
Gain (loss) on dispositions | 39 | ||||||||||
Gain (loss) on dispositions, after tax | $ 23 |
ACQUISITIONS AND DISPOSITIONS_5
ACQUISITIONS AND DISPOSITIONS - Schedule of Construction Projects (Details) - Southern Power $ in Millions | 1 Months Ended | 3 Months Ended | ||||||||
Dec. 31, 2020MW | Nov. 30, 2020USD ($)MW | Jun. 30, 2020USD ($) | May 31, 2020MW | Dec. 31, 2019 | Dec. 31, 2021MW | Sep. 30, 2021MW | Mar. 31, 2020MW | Oct. 31, 2019 | Dec. 31, 2018 | |
Business Acquisition [Line Items] | ||||||||||
Approximate Nameplate Capacity (MW) | 300 | |||||||||
Garland Solar Storage | Scenario, Forecast | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Approximate Nameplate Capacity (MW) | 88 | |||||||||
PPA Contract Period | 20 years | |||||||||
Glass Sands | Scenario, Forecast | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Approximate Nameplate Capacity (MW) | 118 | |||||||||
PPA Contract Period | 12 years | |||||||||
Tranquility Solar Storage | Scenario, Forecast | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Approximate Nameplate Capacity (MW) | 72 | |||||||||
PPA Contract Period | 20 years | |||||||||
Skookumchuck | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Approximate Nameplate Capacity (MW) | 136 | |||||||||
PPA Contract Period | 20 years | |||||||||
Reading | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Approximate Nameplate Capacity (MW) | 200 | |||||||||
PPA Contract Period | 12 years | |||||||||
Wild Horse Mountain | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Approximate Nameplate Capacity (MW) | 100 | |||||||||
PPA Contract Period | 20 years | |||||||||
Garland Solar Storage | Class B Membership Interest | Garland Solar Storage | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Noncontrolling ownership percentage sold by parent | 100.00% | |||||||||
Tranquility Solar Storage | Class B Membership Interest | Tranquility Solar Storage | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Noncontrolling ownership percentage sold by parent | 100.00% | |||||||||
Glass Sands | Glass Sands | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Noncontrolling ownership percentage held by parent | 100.00% | |||||||||
Skookumchuck | Skookumchuck | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Noncontrolling ownership percentage held by parent | 100.00% | |||||||||
Proceeds from tax equity transaction | $ | $ 121 | |||||||||
Skookumchuck | Class B Membership Interest | Skookumchuck | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Noncontrolling ownership percentage held by parent | 100.00% | |||||||||
Reading | Reading | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Noncontrolling ownership percentage held by parent | 100.00% | |||||||||
Proceeds from tax equity transaction | $ | $ 156 | |||||||||
Reading | Class B Membership Interest | Reading | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Noncontrolling ownership percentage held by parent | 100.00% | |||||||||
Wild Horse Mountain | Wild Horse Mountain | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Noncontrolling ownership percentage held by parent | 100.00% | |||||||||
Wild Horse Mountain | Class B Membership Interest | Wild Horse Mountain | ||||||||||
Business Acquisition [Line Items] | ||||||||||
Noncontrolling ownership percentage held by parent | 100.00% |
ACQUISITIONS AND DISPOSITIONS_6
ACQUISITIONS AND DISPOSITIONS - GAS Acquisitions and Dispositions Narrative (Details) | Dec. 01, 2020USD ($) | Feb. 07, 2020USD ($) | May 29, 2019USD ($) | May 31, 2019USD ($) | Jul. 31, 2018USD ($)utility | Jun. 30, 2018USD ($) | Dec. 31, 2020USD ($) | Dec. 31, 2020USD ($) | Dec. 31, 2019USD ($) | Dec. 31, 2018USD ($) | Mar. 24, 2020USD ($) |
Business Acquisition [Line Items] | |||||||||||
Impairment charges | $ 0 | ||||||||||
Gain (loss) on dispositions | $ 66,000,000 | $ 2,588,000,000 | $ 301,000,000 | ||||||||
Southern Company Gas | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Impairment charges | $ 0 | ||||||||||
Number of natural gas distribution utilities sold | utility | 3 | ||||||||||
Gain (loss) on dispositions | 22,000,000 | 0 | 291,000,000 | ||||||||
Southern Company Gas | Triton | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Realized loss on disposal | $ 6,000,000 | ||||||||||
Realized gain on disposal, net of tax | 7,000,000 | ||||||||||
Reversal of federal income tax valuation allowance | $ 13,000,000 | $ 13,000,000 | |||||||||
Southern Company Gas | Pivotal LNG And Atlantic Coast Pipeline | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Contingent milestone payment, amount | $ 5,000,000 | ||||||||||
Pivotal Home Solutions | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Southern Company Gas | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Cash proceeds from sale of business | $ 178,000,000 | $ 365,000,000 | |||||||||
Gain (loss) on dispositions, after tax | (67,000,000) | (17,000,000) | |||||||||
Tax on sale of business | 34,000,000 | ||||||||||
Impairment charges | $ 42,000,000 | $ 42,000,000 | |||||||||
Gain (loss) on dispositions | $ (24,000,000) | ||||||||||
Elizabethtown Gas and Elkton Gas | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Southern Company Gas | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Gain (loss) on dispositions, after tax | $ 0 | ||||||||||
Tax on sale of business | $ 205,000,000 | ||||||||||
Number of natural gas distribution utilities sold | utility | 2 | ||||||||||
Proceeds from sale of oil and gas property and equipment | $ 1,700,000,000 | ||||||||||
Florida City Gas | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Southern Company Gas | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Cash proceeds from sale of business | 587,000,000 | ||||||||||
Gain (loss) on dispositions, after tax | 16,000,000 | ||||||||||
Tax on sale of business | $ 103,000,000 | ||||||||||
Jefferson Island | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Southern Company Gas | |||||||||||
Business Acquisition [Line Items] | |||||||||||
Cash proceeds from sale of business | $ 33,000,000 | ||||||||||
Gain (loss) on dispositions, after tax | 16,000,000 | ||||||||||
Gain (loss) on dispositions | $ 22,000,000 |
ACQUISITIONS AND DISPOSITIONS_7
ACQUISITIONS AND DISPOSITIONS - Held For Sale (Details) - Disposal Group, Held-for-sale, Not Discontinued Operations - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 |
Assets Held for Sale: | ||
Current assets | $ 0 | $ 19 |
Total property, plant, and equipment | 8 | 565 |
Goodwill and other intangible assets | 0 | 40 |
Equity investments in unconsolidated subsidiaries | 0 | 151 |
Leveraged leases | 52 | 0 |
Other non-current assets | 0 | 14 |
Total Assets Held for Sale | 60 | 789 |
Liabilities Held for Sale (all current): | $ 0 | 5 |
Southern Power | ||
Assets Held for Sale: | ||
Current assets | 17 | |
Total property, plant, and equipment | 547 | |
Goodwill and other intangible assets | 40 | |
Equity investments in unconsolidated subsidiaries | 0 | |
Leveraged leases | 0 | |
Other non-current assets | 14 | |
Total Assets Held for Sale | 618 | |
Liabilities Held for Sale (all current): | 3 | |
Southern Company Gas | ||
Assets Held for Sale: | ||
Current assets | 2 | |
Total property, plant, and equipment | 18 | |
Goodwill and other intangible assets | 0 | |
Equity investments in unconsolidated subsidiaries | 151 | |
Leveraged leases | 0 | |
Other non-current assets | 0 | |
Total Assets Held for Sale | 171 | |
Liabilities Held for Sale (all current): | $ 2 |
ACQUISITIONS AND DISPOSITIONS_8
ACQUISITIONS AND DISPOSITIONS - Pre-tax Profit (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Gulf Power | |||
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] | |||
Earnings before income taxes | $ 140 | ||
Florida Plants | Southern Power | |||
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] | |||
Earnings before income taxes | 49 | ||
Plant Nacogdoches | Southern Power | |||
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] | |||
Earnings before income taxes | $ 13 | $ 27 | |
Mankato | Southern Power | |||
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] | |||
Earnings before income taxes | $ 2 | $ 29 |
SEGMENT AND RELATED INFORMATI_3
SEGMENT AND RELATED INFORMATION - Narrative (Details) $ in Millions | 1 Months Ended | 12 Months Ended | ||
Jul. 31, 2018utility | Dec. 31, 2020USD ($)statesegment | Dec. 31, 2019USD ($) | Dec. 31, 2018USD ($) | |
Segment Reporting Information [Line Items] | ||||
Total operating revenues | $ 21,097 | $ 22,596 | $ 25,241 | |
Southern Power | ||||
Segment Reporting Information [Line Items] | ||||
Total operating revenues | 1,119 | 1,220 | 1,364 | |
Southern Company Gas | ||||
Segment Reporting Information [Line Items] | ||||
Total operating revenues | $ 5,039 | 5,598 | 6,914 | |
Number of reportable segments | segment | 4 | |||
Number of states in which entity operates | state | 4 | |||
Number of natural gas distribution utilities sold | utility | 3 | |||
Southern Natural Gas Company, LLC | Southern Company Gas | ||||
Segment Reporting Information [Line Items] | ||||
Ownership percentage, equity method investment | 50.00% | |||
PennEast Pipeline | Southern Company Gas | ||||
Segment Reporting Information [Line Items] | ||||
Ownership percentage, equity method investment | 20.00% | |||
Dalton Pipeline | Southern Company Gas | ||||
Segment Reporting Information [Line Items] | ||||
Ownership percentage, equity method investment | 50.00% | |||
Atlantic Coast Pipeline | Southern Company Gas | ||||
Segment Reporting Information [Line Items] | ||||
Ownership percentage, equity method investment | 5.00% | |||
Natural gas | Southern Company Gas | Traditional Electric Operating Companies | ||||
Segment Reporting Information [Line Items] | ||||
Total operating revenues | $ 0 | 14 | 32 | |
Natural gas | Southern Company Gas | Southern Power | ||||
Segment Reporting Information [Line Items] | ||||
Total operating revenues | $ 26 | $ 64 | $ 119 |
SEGMENT AND RELATED INFORMATI_4
SEGMENT AND RELATED INFORMATION - Financial Data for Business Segments (Details) | Dec. 31, 2020USD ($) | Jun. 30, 2020USD ($) | Jan. 17, 2020USD ($) | Jan. 31, 2019USD ($) | Jun. 30, 2018USD ($) | Dec. 31, 2020USD ($) | Jun. 30, 2020USD ($) | Dec. 31, 2019USD ($) | Dec. 31, 2020USD ($) | Dec. 31, 2019USD ($) | Dec. 31, 2018USD ($)utility |
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | $ 20,375,000,000 | $ 21,419,000,000 | $ 23,495,000,000 | ||||||||
Depreciation and amortization | 3,518,000,000 | 3,038,000,000 | 3,131,000,000 | ||||||||
Interest income | 37,000,000 | 60,000,000 | 38,000,000 | ||||||||
Operating income (loss) | 4,885,000,000 | 7,736,000,000 | 4,191,000,000 | ||||||||
Earnings from equity method investments | 153,000,000 | 162,000,000 | 148,000,000 | ||||||||
Interest expense | 1,821,000,000 | 1,736,000,000 | 1,842,000,000 | ||||||||
Income taxes (benefit) | 393,000,000 | 1,798,000,000 | 449,000,000 | ||||||||
Segment net income (loss) | 3,119,000,000 | 4,739,000,000 | 2,226,000,000 | ||||||||
Goodwill | $ 5,280,000,000 | $ 5,280,000,000 | $ 5,280,000,000 | 5,280,000,000 | 5,280,000,000 | 5,315,000,000 | |||||
Total Assets | 122,935,000,000 | 122,935,000,000 | 118,700,000,000 | 122,935,000,000 | 118,700,000,000 | 116,914,000,000 | |||||
Segment and Related Information (Textual) [Abstract] | |||||||||||
Estimated loss on Plant Vogtle Units 3 and 4 | 325,000,000 | 0 | 1,060,000,000 | ||||||||
Gain (loss) on dispositions | 66,000,000 | 2,588,000,000 | 301,000,000 | ||||||||
Lease, impairment loss | 52,000,000 | $ 154,000,000 | 17,000,000 | 206,000,000 | 0 | 0 | |||||
Lease, impairment loss, after tax | 31,000,000 | $ 74,000,000 | 13,000,000 | ||||||||
Impairment charges | 0 | 168,000,000 | 210,000,000 | ||||||||
Net gain on dispositions | 65,000,000 | 2,569,000,000 | 291,000,000 | ||||||||
Goodwill impairment | 0 | ||||||||||
Electric Utilities | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | 16,497,000,000 | 17,095,000,000 | 18,571,000,000 | ||||||||
Depreciation and amortization | 2,941,000,000 | 2,472,000,000 | 2,565,000,000 | ||||||||
Interest income | 30,000,000 | 47,000,000 | 31,000,000 | ||||||||
Earnings from equity method investments | 0 | 5,000,000 | (1,000,000) | ||||||||
Interest expense | 976,000,000 | 987,000,000 | 1,035,000,000 | ||||||||
Income taxes (benefit) | 517,000,000 | 708,000,000 | 207,000,000 | ||||||||
Segment net income (loss) | 3,115,000,000 | 3,268,000,000 | 2,304,000,000 | ||||||||
Goodwill | 2,000,000 | 2,000,000 | 2,000,000 | 2,000,000 | 2,000,000 | 2,000,000 | |||||
Total Assets | 98,041,000,000 | 98,041,000,000 | 94,650,000,000 | 98,041,000,000 | 94,650,000,000 | 93,959,000,000 | |||||
Southern Company Gas | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | 3,434,000,000 | 3,792,000,000 | 3,909,000,000 | ||||||||
All Other | |||||||||||
Segment and Related Information (Textual) [Abstract] | |||||||||||
Lease, impairment loss | 206,000,000 | ||||||||||
Lease, impairment loss, after tax | 105,000,000 | ||||||||||
Operating Segments | Traditional Operating Companies | Electric Utilities | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | 15,135,000,000 | 15,569,000,000 | 16,843,000,000 | ||||||||
Depreciation and amortization | 2,447,000,000 | 1,993,000,000 | 2,072,000,000 | ||||||||
Interest income | 26,000,000 | 38,000,000 | 23,000,000 | ||||||||
Earnings from equity method investments | 0 | 2,000,000 | (1,000,000) | ||||||||
Interest expense | 825,000,000 | 818,000,000 | 852,000,000 | ||||||||
Income taxes (benefit) | 514,000,000 | 764,000,000 | 371,000,000 | ||||||||
Segment net income (loss) | 2,877,000,000 | 2,929,000,000 | 2,117,000,000 | ||||||||
Goodwill | 0 | 0 | 0 | 0 | 0 | 0 | |||||
Total Assets | 85,486,000,000 | 85,486,000,000 | 81,063,000,000 | 85,486,000,000 | 81,063,000,000 | 79,382,000,000 | |||||
Operating Segments | Southern Power | Electric Utilities | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | 1,733,000,000 | 1,938,000,000 | 2,205,000,000 | ||||||||
Depreciation and amortization | 494,000,000 | 479,000,000 | 493,000,000 | ||||||||
Interest income | 4,000,000 | 9,000,000 | 8,000,000 | ||||||||
Earnings from equity method investments | 0 | 3,000,000 | 0 | ||||||||
Interest expense | 151,000,000 | 169,000,000 | 183,000,000 | ||||||||
Income taxes (benefit) | 3,000,000 | (56,000,000) | (164,000,000) | ||||||||
Segment net income (loss) | 238,000,000 | 339,000,000 | 187,000,000 | ||||||||
Goodwill | 2,000,000 | 2,000,000 | 2,000,000 | 2,000,000 | 2,000,000 | 2,000,000 | |||||
Total Assets | 13,235,000,000 | 13,235,000,000 | 14,300,000,000 | 13,235,000,000 | 14,300,000,000 | 14,883,000,000 | |||||
Operating Segments | Southern Company Gas | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | 3,434,000,000 | 3,792,000,000 | 3,909,000,000 | ||||||||
Depreciation and amortization | 500,000,000 | 487,000,000 | 500,000,000 | ||||||||
Interest income | 5,000,000 | 3,000,000 | 4,000,000 | ||||||||
Earnings from equity method investments | 141,000,000 | 157,000,000 | 148,000,000 | ||||||||
Interest expense | 231,000,000 | 232,000,000 | 228,000,000 | ||||||||
Income taxes (benefit) | 173,000,000 | 130,000,000 | 464,000,000 | ||||||||
Segment net income (loss) | 590,000,000 | 585,000,000 | 372,000,000 | ||||||||
Goodwill | 5,015,000,000 | 5,015,000,000 | 5,015,000,000 | 5,015,000,000 | 5,015,000,000 | 5,015,000,000 | |||||
Total Assets | 22,630,000,000 | 22,630,000,000 | 21,687,000,000 | 22,630,000,000 | 21,687,000,000 | 21,448,000,000 | |||||
Operating Segments | All Other | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | 596,000,000 | 690,000,000 | 1,213,000,000 | ||||||||
Depreciation and amortization | 77,000,000 | 79,000,000 | 66,000,000 | ||||||||
Interest income | 6,000,000 | 16,000,000 | 8,000,000 | ||||||||
Earnings from equity method investments | 12,000,000 | 0 | 2,000,000 | ||||||||
Interest expense | 614,000,000 | 517,000,000 | 580,000,000 | ||||||||
Income taxes (benefit) | (297,000,000) | 960,000,000 | (222,000,000) | ||||||||
Segment net income (loss) | (592,000,000) | 908,000,000 | (453,000,000) | ||||||||
Goodwill | 263,000,000 | 263,000,000 | 263,000,000 | 263,000,000 | 263,000,000 | 298,000,000 | |||||
Total Assets | 3,168,000,000 | 3,168,000,000 | 3,511,000,000 | 3,168,000,000 | 3,511,000,000 | 3,285,000,000 | |||||
Intersegment Eliminations | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | (152,000,000) | (158,000,000) | (198,000,000) | ||||||||
Depreciation and amortization | 0 | 0 | 0 | ||||||||
Interest income | (4,000,000) | (6,000,000) | (5,000,000) | ||||||||
Earnings from equity method investments | 0 | 0 | (1,000,000) | ||||||||
Interest expense | 0 | 0 | (1,000,000) | ||||||||
Income taxes (benefit) | 0 | 0 | 0 | ||||||||
Segment net income (loss) | 6,000,000 | (22,000,000) | 3,000,000 | ||||||||
Goodwill | 0 | 0 | 0 | 0 | 0 | 0 | |||||
Total Assets | (904,000,000) | (904,000,000) | (1,148,000,000) | (904,000,000) | (1,148,000,000) | (1,778,000,000) | |||||
Intersegment Eliminations | Electric Utilities | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | (371,000,000) | (412,000,000) | (477,000,000) | ||||||||
Depreciation and amortization | 0 | 0 | 0 | ||||||||
Interest income | 0 | 0 | 0 | ||||||||
Earnings from equity method investments | 0 | 0 | 0 | ||||||||
Interest expense | 0 | 0 | 0 | ||||||||
Income taxes (benefit) | 0 | 0 | 0 | ||||||||
Segment net income (loss) | 0 | 0 | 0 | ||||||||
Goodwill | 0 | 0 | 0 | 0 | 0 | 0 | |||||
Total Assets | (680,000,000) | (680,000,000) | (713,000,000) | (680,000,000) | (713,000,000) | (306,000,000) | |||||
Georgia Power | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | 8,309,000,000 | 8,408,000,000 | 8,420,000,000 | ||||||||
Depreciation and amortization | 1,425,000,000 | 981,000,000 | 923,000,000 | ||||||||
Operating income (loss) | 1,972,000,000 | 2,461,000,000 | 1,289,000,000 | ||||||||
Interest expense | 425,000,000 | 409,000,000 | 397,000,000 | ||||||||
Income taxes (benefit) | 152,000,000 | 472,000,000 | 214,000,000 | ||||||||
Total Assets | 47,080,000,000 | 47,080,000,000 | 44,541,000,000 | 47,080,000,000 | 44,541,000,000 | ||||||
Segment and Related Information (Textual) [Abstract] | |||||||||||
Estimated loss on Plant Vogtle Units 3 and 4 | 325,000,000 | 0 | 1,060,000,000 | ||||||||
Georgia Power | Plant Vogtle Units 3 And 4 | |||||||||||
Segment and Related Information (Textual) [Abstract] | |||||||||||
Estimated loss on Plant Vogtle Units 3 and 4 | 176,000,000 | $ 149,000,000 | |||||||||
Estimated loss on Plant Vogtle Units 3 and 4, net of tax | 131,000,000 | $ 111,000,000 | |||||||||
Georgia Power | Traditional Operating Companies | Plant Vogtle Units 3 And 4 | |||||||||||
Segment and Related Information (Textual) [Abstract] | |||||||||||
Estimated loss on Plant Vogtle Units 3 and 4 | 325,000,000 | 1,100,000,000 | |||||||||
Estimated loss on Plant Vogtle Units 3 and 4, net of tax | 242,000,000 | 800,000,000 | |||||||||
Southern Power | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | 1,733,000,000 | 1,938,000,000 | 2,205,000,000 | ||||||||
Depreciation and amortization | 494,000,000 | 479,000,000 | 493,000,000 | ||||||||
Operating income (loss) | 342,000,000 | 395,000,000 | 242,000,000 | ||||||||
Interest expense | 151,000,000 | 169,000,000 | 183,000,000 | ||||||||
Income taxes (benefit) | 3,000,000 | (56,000,000) | (164,000,000) | ||||||||
Segment net income (loss) | 238,000,000 | 339,000,000 | 187,000,000 | ||||||||
Total Assets | 13,235,000,000 | 13,235,000,000 | 14,300,000,000 | 13,235,000,000 | 14,300,000,000 | ||||||
Segment and Related Information (Textual) [Abstract] | |||||||||||
Gain (loss) on dispositions | 39,000,000 | 24,000,000 | 3,000,000 | ||||||||
Impairment charges | 0 | 3,000,000 | 156,000,000 | ||||||||
Impairment charges, after tax | 117,000,000 | ||||||||||
Net gain on dispositions | 39,000,000 | 23,000,000 | 2,000,000 | ||||||||
Southern Company Gas | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | 3,434,000,000 | 3,792,000,000 | 3,909,000,000 | ||||||||
Depreciation and amortization | 500,000,000 | 487,000,000 | 500,000,000 | ||||||||
Operating income (loss) | 812,000,000 | 770,000,000 | 915,000,000 | ||||||||
Earnings from equity method investments | 141,000,000 | 157,000,000 | 148,000,000 | ||||||||
Interest expense | 231,000,000 | 232,000,000 | 228,000,000 | ||||||||
Income taxes (benefit) | 173,000,000 | 130,000,000 | 464,000,000 | ||||||||
Segment net income (loss) | 590,000,000 | 585,000,000 | 372,000,000 | ||||||||
Goodwill | 5,015,000,000 | 5,015,000,000 | 5,015,000,000 | 5,015,000,000 | 5,015,000,000 | ||||||
Total Assets | 22,630,000,000 | 22,630,000,000 | 21,687,000,000 | 22,630,000,000 | 21,687,000,000 | 21,448,000,000 | |||||
Segment and Related Information (Textual) [Abstract] | |||||||||||
Gain (loss) on dispositions | 22,000,000 | 0 | 291,000,000 | ||||||||
Impairment charges | 0 | 115,000,000 | 42,000,000 | ||||||||
Net gain on dispositions | 22,000,000 | 0 | 291,000,000 | ||||||||
Goodwill impairment | 0 | ||||||||||
Southern Company Gas | Gas distribution operations | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Goodwill | 4,034,000,000 | 4,034,000,000 | 4,034,000,000 | 4,034,000,000 | 4,034,000,000 | ||||||
Southern Company Gas | Gas marketing services | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Goodwill | 981,000,000 | 981,000,000 | 981,000,000 | 981,000,000 | 981,000,000 | ||||||
Segment and Related Information (Textual) [Abstract] | |||||||||||
Net gain on dispositions | (33,000,000) | ||||||||||
Net gain on dispositions, after tax | (67,000,000) | ||||||||||
Disposal group, including discontinued operation, revenue | 55,000,000 | ||||||||||
Southern Company Gas | Operating Segments | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | 3,466,000,000 | 3,810,000,000 | 3,930,000,000 | ||||||||
Depreciation and amortization | 470,000,000 | 454,000,000 | 453,000,000 | ||||||||
Operating income (loss) | 814,000,000 | 924,000,000 | 1,013,000,000 | ||||||||
Earnings from equity method investments | 141,000,000 | 162,000,000 | 145,000,000 | ||||||||
Interest expense | 228,000,000 | 225,000,000 | 227,000,000 | ||||||||
Income taxes (benefit) | 178,000,000 | 200,000,000 | 495,000,000 | ||||||||
Segment net income (loss) | 592,000,000 | 677,000,000 | 435,000,000 | ||||||||
Total Assets | 23,040,000,000 | 23,040,000,000 | 22,228,000,000 | 23,040,000,000 | 22,228,000,000 | 21,918,000,000 | |||||
Southern Company Gas | Operating Segments | All Other | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | 36,000,000 | 44,000,000 | 55,000,000 | ||||||||
Depreciation and amortization | 30,000,000 | 33,000,000 | 47,000,000 | ||||||||
Operating income (loss) | (7,000,000) | (154,000,000) | (98,000,000) | ||||||||
Earnings from equity method investments | 0 | (5,000,000) | 3,000,000 | ||||||||
Interest expense | 3,000,000 | 7,000,000 | 1,000,000 | ||||||||
Income taxes (benefit) | (5,000,000) | (70,000,000) | (31,000,000) | ||||||||
Segment net income (loss) | (2,000,000) | (92,000,000) | (63,000,000) | ||||||||
Total Assets | 11,336,000,000 | 11,336,000,000 | 10,759,000,000 | 11,336,000,000 | 10,759,000,000 | 11,112,000,000 | |||||
Southern Company Gas | Operating Segments | Gas distribution operations | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | 2,952,000,000 | 3,028,000,000 | 3,186,000,000 | ||||||||
Depreciation and amortization | 442,000,000 | 422,000,000 | 409,000,000 | ||||||||
Operating income (loss) | 655,000,000 | 573,000,000 | 904,000,000 | ||||||||
Earnings from equity method investments | 0 | 0 | 0 | ||||||||
Interest expense | 192,000,000 | 187,000,000 | 178,000,000 | ||||||||
Income taxes (benefit) | 114,000,000 | 63,000,000 | 409,000,000 | ||||||||
Segment net income (loss) | 390,000,000 | 337,000,000 | 334,000,000 | ||||||||
Total Assets | 19,090,000,000 | 19,090,000,000 | 18,204,000,000 | 19,090,000,000 | 18,204,000,000 | 17,266,000,000 | |||||
Southern Company Gas | Operating Segments | Gas Pipeline Investments | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | 32,000,000 | 32,000,000 | 32,000,000 | ||||||||
Depreciation and amortization | 5,000,000 | 5,000,000 | 5,000,000 | ||||||||
Operating income (loss) | 20,000,000 | 20,000,000 | 20,000,000 | ||||||||
Earnings from equity method investments | 141,000,000 | 162,000,000 | 145,000,000 | ||||||||
Interest expense | 29,000,000 | 30,000,000 | 34,000,000 | ||||||||
Income taxes (benefit) | 33,000,000 | 58,000,000 | 28,000,000 | ||||||||
Segment net income (loss) | 99,000,000 | 94,000,000 | 103,000,000 | ||||||||
Total Assets | 1,597,000,000 | 1,597,000,000 | 1,678,000,000 | 1,597,000,000 | 1,678,000,000 | 1,763,000,000 | |||||
Southern Company Gas | Operating Segments | Wholesale gas services | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | 74,000,000 | 294,000,000 | 144,000,000 | ||||||||
Depreciation and amortization | 1,000,000 | 1,000,000 | 2,000,000 | ||||||||
Operating income (loss) | 20,000,000 | 219,000,000 | 70,000,000 | ||||||||
Earnings from equity method investments | 0 | 0 | 0 | ||||||||
Interest expense | 4,000,000 | 5,000,000 | 9,000,000 | ||||||||
Income taxes (benefit) | 3,000,000 | 52,000,000 | 4,000,000 | ||||||||
Segment net income (loss) | 14,000,000 | 163,000,000 | 38,000,000 | ||||||||
Total Assets | 850,000,000 | 850,000,000 | 850,000,000 | 850,000,000 | 850,000,000 | 1,302,000,000 | |||||
Southern Company Gas | Operating Segments | Gas marketing services | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | 408,000,000 | 456,000,000 | 568,000,000 | ||||||||
Depreciation and amortization | 22,000,000 | 26,000,000 | 37,000,000 | ||||||||
Operating income (loss) | 119,000,000 | 112,000,000 | 19,000,000 | ||||||||
Earnings from equity method investments | 0 | 0 | 0 | ||||||||
Interest expense | 3,000,000 | 3,000,000 | 6,000,000 | ||||||||
Income taxes (benefit) | 28,000,000 | 27,000,000 | 54,000,000 | ||||||||
Segment net income (loss) | 89,000,000 | 83,000,000 | (40,000,000) | ||||||||
Total Assets | 1,503,000,000 | 1,503,000,000 | 1,496,000,000 | 1,503,000,000 | 1,496,000,000 | 1,587,000,000 | |||||
Southern Company Gas | Intersegment Eliminations | |||||||||||
Segment Reporting Information [Line Items] | |||||||||||
Total operating revenues | (68,000,000) | (62,000,000) | (76,000,000) | ||||||||
Depreciation and amortization | 0 | 0 | 0 | ||||||||
Operating income (loss) | 5,000,000 | 0 | 0 | ||||||||
Earnings from equity method investments | 0 | 0 | 0 | ||||||||
Interest expense | 0 | 0 | 0 | ||||||||
Income taxes (benefit) | 0 | 0 | 0 | ||||||||
Segment net income (loss) | 0 | 0 | 0 | ||||||||
Total Assets | $ (11,746,000,000) | $ (11,746,000,000) | $ (11,300,000,000) | (11,746,000,000) | (11,300,000,000) | (11,582,000,000) | |||||
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Southern Company Gas | Gas distribution operations | |||||||||||
Segment and Related Information (Textual) [Abstract] | |||||||||||
Net gain on dispositions | 324,000,000 | ||||||||||
Net gain on dispositions, after tax | $ 16,000,000 | ||||||||||
Number of distribution utilities | utility | 3 | ||||||||||
Disposal group, including discontinued operation, revenue | $ 244,000,000 | ||||||||||
Mankato | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Southern Power | |||||||||||
Segment and Related Information (Textual) [Abstract] | |||||||||||
Gain on sale | 39,000,000 | ||||||||||
Gain on sale, after tax | 23,000,000 | ||||||||||
Gain (loss) on dispositions | $ 39,000,000 | ||||||||||
Gain (loss) on dispositions, after tax | $ 23,000,000 | ||||||||||
Plant Nacogdoches | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Southern Power | |||||||||||
Segment and Related Information (Textual) [Abstract] | |||||||||||
Gain (loss) on dispositions | 23,000,000 | ||||||||||
Gain (loss) on dispositions, after tax | 88,000,000 | ||||||||||
Gulf Power | Disposal Group, Disposed of by Sale, Not Discontinued Operations | |||||||||||
Segment and Related Information (Textual) [Abstract] | |||||||||||
Gain (loss) on dispositions | $ 2,600,000,000 | 2,600,000,000 | |||||||||
Gain (loss) on dispositions, after tax | $ 1,400,000,000 | 1,400,000,000 | |||||||||
PowerSecure International, Inc. Lighting Business | Disposal Group, Disposed of by Sale, Not Discontinued Operations | |||||||||||
Segment and Related Information (Textual) [Abstract] | |||||||||||
Gain (loss) on dispositions | (58,000,000) | ||||||||||
Gain (loss) on dispositions, after tax | (52,000,000) | ||||||||||
Pivotal Home Solutions | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Southern Company Gas | |||||||||||
Segment and Related Information (Textual) [Abstract] | |||||||||||
Gain (loss) on dispositions | (24,000,000) | ||||||||||
Gain (loss) on dispositions, after tax | $ (67,000,000) | (17,000,000) | |||||||||
Net gain on dispositions | 291,000,000 | ||||||||||
Net gain on dispositions, after tax | (51,000,000) | ||||||||||
Goodwill impairment | $ 42,000,000 | $ 42,000,000 | |||||||||
Jefferson Island | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Southern Company Gas | |||||||||||
Segment and Related Information (Textual) [Abstract] | |||||||||||
Gain (loss) on dispositions | 22,000,000 | ||||||||||
Gain (loss) on dispositions, after tax | $ 16,000,000 | ||||||||||
Natural Gas Storage Facility | Southern Company Gas | |||||||||||
Segment and Related Information (Textual) [Abstract] | |||||||||||
Impairment charges | 115,000,000 | ||||||||||
Impairment charges, after tax | $ 86,000,000 |
SEGMENT AND RELATED INFORMATI_5
SEGMENT AND RELATED INFORMATION - Electric Utilities' Revenues (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Revenue from External Customer [Line Items] | |||
Total operating revenues | $ 20,375 | $ 21,419 | $ 23,495 |
Other electric revenues | |||
Revenue from External Customer [Line Items] | |||
Total operating revenues | 672 | 636 | 664 |
Electric Utilities | |||
Revenue from External Customer [Line Items] | |||
Total operating revenues | 16,497 | 17,095 | 18,571 |
Electric Utilities | Retail electric revenues | |||
Revenue from External Customer [Line Items] | |||
Total operating revenues | 13,643 | 14,084 | 15,222 |
Electric Utilities | Wholesale electric revenues | |||
Revenue from External Customer [Line Items] | |||
Total operating revenues | 1,945 | 2,152 | 2,516 |
Electric Utilities | Other electric revenues | |||
Revenue from External Customer [Line Items] | |||
Total operating revenues | $ 909 | $ 859 | $ 833 |
SEGMENT AND RELATED INFORMATI_6
SEGMENT AND RELATED INFORMATION - Gas Revenues (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Segment Reporting Information [Line Items] | |||
Total operating revenues | $ 20,375 | $ 21,419 | $ 23,495 |
Southern Company Gas | |||
Segment Reporting Information [Line Items] | |||
Total operating revenues | 3,434 | 3,792 | 3,909 |
Operating Segments | Southern Company Gas | |||
Segment Reporting Information [Line Items] | |||
Total operating revenues | 3,466 | 3,810 | 3,930 |
Southern Company Gas | |||
Segment Reporting Information [Line Items] | |||
Total operating revenues | 3,434 | 3,792 | 3,909 |
Southern Company Gas | Gas distribution operations | |||
Segment Reporting Information [Line Items] | |||
Total operating revenues | 2,902 | 3,001 | 3,155 |
Southern Company Gas | Gas marketing services | |||
Segment Reporting Information [Line Items] | |||
Total operating revenues | 408 | 456 | 568 |
Southern Company Gas | Other Gas Revenue | |||
Segment Reporting Information [Line Items] | |||
Total operating revenues | 124 | 335 | 186 |
Southern Company Gas | Operating Segments | |||
Segment Reporting Information [Line Items] | |||
Total operating revenues | 3,434 | 3,792 | 3,909 |
Wholesale gas services | Operating Segments | Southern Company Gas | |||
Segment Reporting Information [Line Items] | |||
Total operating revenues | 74 | 294 | 144 |
Less Gross Gas Costs | 4,585 | 5,684 | 7,262 |
Wholesale gas services | Operating Segments | Third Party Gross Revenues | Southern Company Gas | |||
Segment Reporting Information [Line Items] | |||
Total operating revenues | 4,544 | 5,703 | 6,955 |
Wholesale gas services | Operating Segments | Intercompany Revenues | Southern Company Gas | |||
Segment Reporting Information [Line Items] | |||
Total operating revenues | 115 | 275 | 451 |
Wholesale gas services | Operating Segments | Total Gross Revenues | Southern Company Gas | |||
Segment Reporting Information [Line Items] | |||
Total operating revenues | $ 4,659 | $ 5,978 | $ 7,406 |
VALUATION AND QUALIFYING ACCO_2
VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Millions | May 29, 2019 | May 31, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 |
Provision for uncollectible accounts | |||||
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | |||||
Balance at Beginning of Period | $ 49 | $ 50 | $ 44 | ||
Charged to Income | 78 | 68 | 69 | ||
Charged to Other Accounts | 27 | 0 | (1) | ||
Deductions | 36 | 69 | 61 | ||
Reclassified to Held for Sale | 0 | 0 | 1 | ||
Balance at End of Period | 118 | 49 | 50 | ||
Tax valuation allowance (net state) | |||||
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | |||||
Balance at Beginning of Period | 113 | 100 | 148 | ||
Charged to Income | 0 | 13 | (38) | ||
Charged to Other Accounts | 0 | 0 | 0 | ||
Deductions | 1 | 0 | 10 | ||
Reclassified to Held for Sale | 0 | 0 | 0 | ||
Balance at End of Period | 112 | 113 | 100 | ||
Alabama Power | Provision for uncollectible accounts | |||||
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | |||||
Balance at Beginning of Period | 22 | 10 | 9 | ||
Charged to Income | 25 | 24 | 13 | ||
Charged to Other Accounts | 0 | 0 | 0 | ||
Deductions | 4 | 12 | 12 | ||
Balance at End of Period | 43 | 22 | 10 | ||
Georgia Power | Provision for uncollectible accounts | |||||
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | |||||
Balance at Beginning of Period | 2 | 2 | 3 | ||
Charged to Income | 14 | 13 | 11 | ||
Charged to Other Accounts | 23 | 0 | 0 | ||
Deductions | 13 | 13 | 12 | ||
Balance at End of Period | 26 | 2 | 2 | ||
Georgia Power | Tax valuation allowance (net state) | |||||
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | |||||
Balance at Beginning of Period | 28 | 33 | 0 | ||
Charged to Income | 0 | (5) | 39 | ||
Charged to Other Accounts | 0 | 0 | 0 | ||
Deductions | 0 | 0 | 6 | ||
Balance at End of Period | 28 | 28 | 33 | ||
Mississippi Power | Provision for uncollectible accounts | |||||
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | |||||
Balance at Beginning of Period | 1 | 1 | 1 | ||
Charged to Income | 1 | 2 | 1 | ||
Charged to Other Accounts | 0 | 0 | 0 | ||
Deductions | 1 | 2 | 1 | ||
Balance at End of Period | 1 | 1 | 1 | ||
Mississippi Power | Tax valuation allowance (net state) | |||||
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | |||||
Balance at Beginning of Period | 32 | 32 | 124 | ||
Charged to Income | 0 | 0 | (92) | ||
Charged to Other Accounts | 0 | 0 | 0 | ||
Deductions | 0 | 0 | 0 | ||
Balance at End of Period | 32 | 32 | 32 | ||
Southern Power | Tax valuation allowance (net state) | |||||
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | |||||
Balance at Beginning of Period | 29 | 22 | 10 | ||
Charged to Income | (1) | 7 | 12 | ||
Charged to Other Accounts | 0 | 0 | 0 | ||
Deductions | 1 | 0 | 0 | ||
Balance at End of Period | 27 | 29 | 22 | ||
Southern Company Gas | Provision for uncollectible accounts | |||||
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | |||||
Balance at Beginning of Period | 18 | 30 | 28 | ||
Charged to Income | 35 | 29 | 33 | ||
Charged to Other Accounts | 4 | 0 | (1) | ||
Deductions | 17 | 41 | 30 | ||
Balance at End of Period | 40 | 18 | 30 | ||
Southern Company Gas | Tax valuation allowance (net state) | |||||
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | |||||
Balance at Beginning of Period | 4 | 12 | 11 | ||
Charged to Income | 0 | (8) | 1 | ||
Charged to Other Accounts | 0 | 0 | 0 | ||
Deductions | 0 | 0 | 0 | ||
Balance at End of Period | 4 | $ 4 | $ 12 | ||
Triton | Southern Company Gas | |||||
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | |||||
Reversal of federal income tax valuation allowance | $ 13 | $ 13 | |||
State and Local Jurisdiction | Georgia Power | |||||
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | |||||
Valuation allowance | 28 | ||||
State and Local Jurisdiction | Southern Company Gas | |||||
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | |||||
Valuation allowance | $ 5 |