Document and Entity Information
Document and Entity Information - USD ($) | 12 Months Ended | ||
Dec. 31, 2018 | Feb. 22, 2019 | Jun. 29, 2018 | |
Document and Entity Information [Abstract] | |||
Entity Registrant Name | SOUTHWESTERN PUBLIC SERVICE CO | ||
Entity Central Index Key | 92,521 | ||
Current Fiscal Year End Date | --12-31 | ||
Entity Well-Known Season Issuer | Yes | ||
Entity Voluntary Filers | No | ||
Entity Current Reporting Status | Yes | ||
Entity Filer Category | Non-accelerated Filer | ||
Document Type | 10-K | ||
Document Period End Date | Dec. 31, 2018 | ||
Document Fiscal Year Focus | 2,018 | ||
Document Fiscal Period Focus | FY | ||
Amendment Flag | false | ||
Entity Public Float | $ 0 | ||
Entity Common Stock, Shares Outstanding | 100 | ||
Entity Small Business | false | ||
Entity Shell Company | false | ||
Entity Emerging Growth Company | false |
STATEMENTS OF CASH FLOWS
STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Operating activities | |||
Net income | $ 213,300 | $ 159,200 | $ 152,200 |
Adjustments to reconcile net income to cash provided by operating activities: | |||
Depreciation and amortization | 210,000 | 193,900 | 163,000 |
Deferred income taxes | 22,100 | 126,500 | 123,000 |
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity | (19,100) | (9,300) | (10,000) |
Amortization of Regulatory Asset | 1,700 | 1,700 | 0 |
Provision for bad debts | 4,900 | 5,100 | 6,100 |
Net derivative losses | 100 | 100 | 200 |
Changes in operating assets and liabilities: | |||
Accounts receivable | 19,500 | 10,400 | 8,900 |
Accrued unbilled revenues | (15,300) | 10,400 | 15,600 |
Inventories | (16,000) | 1,900 | 1,000 |
Prepayments and other | (500) | (4,300) | (22,700) |
Accounts payable | (6,600) | 11,800 | 13,800 |
Net regulatory assets and liabilities | (38,200) | (38,100) | 55,700 |
Other current liabilities | 11,600 | 3,400 | 5,200 |
Pension and other employee benefit obligations | (16,000) | (21,700) | (15,300) |
Other | (5,800) | 19,900 | (8,100) |
Net cash provided by operating activities | 446,300 | 470,500 | 387,800 |
Investing activities | |||
Utility capital/construction expenditures | (1,020,900) | (550,600) | (502,500) |
Proceeds from insurance recoveries | 0 | 0 | 3,900 |
Investments in utility money pool arrangement | (285,000) | (142,000) | (75,000) |
Receipts from utility money pool arrangement | 350,000 | 77,000 | 75,000 |
Other | 0 | (500) | 1,300 |
Net cash used in investing activities | (955,900) | (616,100) | (499,900) |
Financing activities | |||
Proceeds from (repayments of) short-term borrowings, net | 42,000 | (50,000) | 35,000 |
Proceeds from issuance of long-term debt | 295,000 | 442,300 | 296,000 |
Repayment of long-term debt, including reacquisition premiums | 0 | (271,600) | (200,000) |
Borrowings under utility money pool arrangement | 595,000 | 335,000 | 636,500 |
Repayments under utility money pool arrangement | (595,000) | (335,000) | (636,500) |
Capital contributions from parent | 336,800 | 143,700 | 66,200 |
Dividends paid to parent | (131,000) | (108,800) | (85,100) |
Net cash provided by financing activities | 542,800 | 155,600 | 112,100 |
Net change in cash and cash equivalents | 33,200 | 10,000 | 0 |
Cash and cash equivalents at beginning of period | 10,800 | 800 | 800 |
Cash and cash equivalents at end of period | 44,000 | 10,800 | 800 |
Supplemental disclosure of cash flow information: | |||
Cash paid for interest (net of amounts capitalized) | (71,200) | (76,000) | (78,200) |
Cash paid for income taxes, net | 10,600 | (41,500) | (61,800) |
Supplemental disclosure of non-cash investing transactions: | |||
Inventory transfers to plant, property and equipment | 0 | 13,700 | 22,600 |
Property, plant and equipment additions in accounts payable | 71,500 | 85,100 | 49,500 |
Allowance for Funds Used During Construction, Investing Activities | $ 19,100 | $ 9,300 | $ 10,000 |
STATEMENTS OF COMMON STOCKHOLDE
STATEMENTS OF COMMON STOCKHOLDER'S EQUITY - USD ($) $ in Thousands | Total | Common stock | Additional Paid In Capital | Retained Earnings | AOCI Attributable to Parent |
Beginning Balance at Dec. 31, 2015 | $ 1,807,900 | $ 0 | $ 1,371,200 | $ 438,000 | $ (1,300) |
Beginning Balance (in shares) at Dec. 31, 2015 | 100 | ||||
Comprehensive income: | |||||
Net income | 152,200 | 152,200 | |||
Other comprehensive income | 0 | ||||
Common dividends declared to parent | (103,500) | 103,500 | |||
Contribution of capital by parent | 75,000 | 75,000 | |||
Ending Balance at Dec. 31, 2016 | 1,931,600 | $ 0 | 1,446,200 | 486,700 | (1,300) |
Ending Balance (in shares) at Dec. 31, 2016 | 100 | ||||
Comprehensive income: | |||||
Net income | 159,200 | 159,200 | |||
Other comprehensive income | 100 | 100 | |||
Common dividends declared to parent | (104,600) | 104,600 | |||
Contribution of capital by parent | 144,000 | 144,000 | |||
Adoption of ASU No. 2018-02 | 0 | 0 | (300) | ||
Ending Balance at Dec. 31, 2017 | $ 2,130,300 | $ 0 | 1,590,200 | 541,600 | (1,500) |
Ending Balance (in shares) at Dec. 31, 2017 | 100 | 100 | |||
Comprehensive income: | |||||
Net income | $ 213,300 | 213,300 | |||
Other comprehensive income | 100 | 100 | |||
Common dividends declared to parent | (149,200) | 149,200 | |||
Contribution of capital by parent | 342,100 | 342,100 | |||
Ending Balance at Dec. 31, 2018 | $ 2,536,600 | $ 0 | $ 1,932,300 | $ 605,700 | $ (1,400) |
Ending Balance (in shares) at Dec. 31, 2018 | 100 | 100 |
STATEMENTS OF INCOME
STATEMENTS OF INCOME - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Revenues [Abstract] | |||
Revenues | $ 1,933,200 | $ 1,918,000 | $ 1,851,000 |
Operating expenses | |||
Electric fuel and purchased power | 1,043,500 | 1,055,300 | 1,035,000 |
Operating and maintenance expenses | 282,700 | 285,400 | 265,500 |
Demand side management program expenses | 17,700 | 15,500 | 16,000 |
Depreciation and amortization | 209,600 | 193,900 | 162,400 |
Taxes (other than income taxes) | 68,000 | 67,000 | 60,800 |
Total operating expenses | 1,621,500 | 1,617,100 | 1,539,700 |
Operating income | 311,700 | 300,900 | 311,300 |
Other income (expense), net | (3,000) | (1,800) | (3,900) |
Allowance for funds used during construction — equity | 19,100 | 9,300 | 10,000 |
Interest charges and financing costs | |||
Interest charges — includes other financing costs of $2.9, $2.5 and $3.1, respectively | 84,500 | 86,200 | 88,700 |
Public Utilities, Allowance For Funds Used During Construction, Capitalized Cost Of Debt | (8,900) | (5,400) | (5,600) |
Total interest charges and financing costs | 75,600 | 80,800 | 83,100 |
Income before income taxes | 252,200 | 227,600 | 234,300 |
Income taxes | 38,900 | 68,400 | 82,100 |
Net income | $ 213,300 | $ 159,200 | $ 152,200 |
STATEMENTS OF INCOME (Parenthet
STATEMENTS OF INCOME (Parenthetical) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Interest charges and financing costs | |||
Other financing costs | $ 2,900 | $ 2,500 | $ 3,100 |
BALANCE SHEETS
BALANCE SHEETS - USD ($) $ in Thousands | Dec. 31, 2018 | Dec. 31, 2017 |
Current assets | ||
Cash and cash equivalents | $ 44,000 | $ 10,800 |
Accounts receivable, net | 90,700 | 79,600 |
Accounts receivable from affiliates | 10,500 | 1,300 |
Investments in money pool arrangements | 0 | 65,000 |
Accrued unbilled revenues | 114,500 | 129,800 |
Inventory | 33,900 | 40,400 |
Regulatory assets | 26,000 | 31,500 |
Derivative instruments | 17,800 | 15,900 |
Prepaid taxes | 14,200 | 15,000 |
Prepayments and other | 10,700 | 10,400 |
Total current assets | 362,300 | 399,700 |
Property, plant and equipment, net | 5,946,400 | 5,095,600 |
Other assets | ||
Regulatory assets | 366,200 | 362,900 |
Derivative instruments | 15,800 | 19,000 |
Other | 5,100 | 11,300 |
Total other assets | 387,100 | 393,200 |
Total assets | 6,695,800 | 5,888,500 |
Current liabilities | ||
Short-term debt | 42,000 | 0 |
Accounts payable | 191,800 | 211,800 |
Accounts payable to affiliates | 19,900 | 22,600 |
Regulatory liabilities | 85,800 | 68,800 |
Taxes accrued | 41,600 | 35,200 |
Accrued interest | 25,800 | 23,300 |
Dividends payable | 45,200 | 26,800 |
Derivative instruments | 3,600 | 3,600 |
Other | 28,300 | 29,600 |
Total current liabilities | 484,000 | 421,700 |
Deferred credits and other liabilities | ||
Deferred income taxes | 619,100 | 574,900 |
Regulatory liabilities | 780,900 | 784,600 |
Asset retirement obligations | 32,400 | 28,500 |
Derivative instruments | 16,400 | 20,000 |
Pension and employee benefit obligations | 92,400 | 90,300 |
Other | 7,900 | 8,300 |
Total deferred credits and other liabilities | 1,549,100 | 1,506,600 |
Commitments and contingencies | ||
Capitalization | ||
Long-term debt | 2,126,100 | 1,829,900 |
Common stock — 200 shares authorized of $1.00 par value; 100 shares outstanding at Dec. 31, 2018 and 2017, respectively | 0 | 0 |
Additional paid in capital | 1,932,300 | 1,590,200 |
Retained earnings | 605,700 | 541,600 |
Accumulated other comprehensive loss | (1,400) | (1,500) |
Total common stockholder’s equity | 2,536,600 | 2,130,300 |
Total liabilities and equity | $ 6,695,800 | $ 5,888,500 |
BALANCE SHEETS (Parenthetical)
BALANCE SHEETS (Parenthetical) - $ / shares | Dec. 31, 2018 | Dec. 31, 2017 |
Capitalization, Long-term Debt and Equity [Abstract] | ||
Common stock, shares authorized (in shares) | 200 | 200 |
Common stock, par value (in dollars per share) | $ 1 | $ 1 |
Common stock, shares outstanding (in shares) | 100 | 100 |
STATEMENTS OF COMPREHENSIVE INC
STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax | $ 100 | $ 0 | $ 100 |
Other comprehensive income | 100 | 100 | 0 |
Comprehensive income: | |||
Net income | 213,300 | 159,200 | 152,200 |
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax | 0 | 100 | (100) |
Derivative instruments: | |||
Comprehensive Income (Loss), Net of Tax, Attributable to Parent | $ 213,400 | $ 159,300 | $ 152,200 |
STATEMENTS OF COMPREHENSIVE I_2
STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Derivative instruments: | |||
Reclassification of losses to net income, tax | $ 0 | $ (100) | $ (100) |
Amortization of losses (gains) included in net periodic benefit cost, tax | $ 0 | $ 0 | $ (100) |
STATEMENTS OF CAPITALIZATION
STATEMENTS OF CAPITALIZATION - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017 |
Common Stockholder's Equity | ||
Common stock — 200 shares authorized of $1.00 par value; 100 shares outstanding at Dec. 31, 2018 and 2017, respectively | $ 0 | $ 0 |
Additional paid in capital | 1,932.3 | 1,590.2 |
Retained earnings | 605.7 | 541.6 |
Accumulated other comprehensive loss | (1.4) | (1.5) |
Total common stockholder’s equity | $ 2,536.6 | $ 2,130.3 |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 12 Months Ended |
Dec. 31, 2018 | |
Accounting Policies [Abstract] | |
Summary of Significant Accounting Policies | Summary of Significant Accounting Policies General — SPS is engaged in the regulated generation, purchase, transmission, distribution and sale of electricity. SPS’ financial statements and disclosures are presented in accordance with GAAP. All of SPS’ underlying accounting records also conform to the FERC uniform system of accounts or to systems required by various state regulatory commissions. SPS has evaluated the impact of events occurring after Dec. 31, 2018 up to the date of issuance of these financial statements. These statements contain all necessary adjustments and disclosures resulting from that evaluation. Use of Estimates — SPS uses estimates based on the best information available in recording transactions and balances resulting from business operations. Estimates are used on items such as plant depreciable lives or potential disallowances, AROs, certain regulatory assets and liabilities, tax provisions, uncollectible amounts, environmental costs, unbilled revenues, jurisdictional fuel and energy cost allocations and actuarially determined benefit costs. Recorded estimates are revised when better information becomes available or when actual amounts can be determined. Those revisions can affect operating results. Regulatory Accounting — SPS accounts for income and expense items in accordance with accounting guidance for regulated operations. Under this guidance: • Certain costs, which would otherwise be charged to expense or other comprehensive income, are deferred as regulatory assets based on the expected ability to recover the costs in future rates; and • Certain credits, which would otherwise be reflected as income or other comprehensive income, are deferred as regulatory liabilities based on the expectation the amounts will be returned to customers in future rates, or because the amounts were collected in rates prior to the costs being incurred. Estimates of recovering deferred costs and returning deferred credits are based on specific ratemaking decisions or precedent for each item. Regulatory assets and liabilities are amortized consistent with the treatment in the rate setting process. If changes in the regulatory environment occur, SPS may no longer be eligible to apply this accounting treatment, and may be required to eliminate regulatory assets and liabilities from its balance sheet. Such changes could have a material effect on SPS’ results of operations, financial condition or cash flows. See Note 4 for further information. Income Taxes — SPS accounts for income taxes using the asset and liability method, which requires deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. SPS defers income taxes for all temporary differences between pretax financial and taxable income, and between the book and tax bases of assets and liabilities. SPS uses the tax rates that are scheduled to be in effect when the temporary differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in the period that includes the enactment date. The effects of SPS’ tax rate changes are generally subject to a normalization method of accounting. Therefore, the revaluation of most its net deferred taxes upon a tax rate reduction results in the establishment of a net regulatory liability which will be refundable to utility customers over the remaining life of the related assets. A tax rate increase would result in the establishment of a similar regulatory asset. Tax credits are recorded when earned unless there is a requirement to defer the benefit and amortize it over the book depreciable lives of the related property. The requirement to defer and amortize tax credits only applies to federal ITCs related to public utility property. Utility rate regulation also has resulted in the recognition of regulatory assets and liabilities related to income taxes. Deferred tax assets are reduced by a valuation allowance if it is more likely than not that some portion or all of the deferred tax asset will not be realized. SPS follows the applicable accounting guidance to measure and disclose uncertain tax positions that it has taken or expects to take in its income tax returns. SPS recognizes a tax position in its financial statements when it is more likely than not that the position will be sustained upon examination based on the technical merits of the position. Recognition of changes in uncertain tax positions are reflected as a component of income tax. SPS reports interest and penalties related to income taxes within the other income and interest charges in the statements of income. Xcel Energy Inc. and its subsidiaries, including SPS, files consolidated federal income tax returns as well as consolidated or separate state income tax returns. Federal income taxes paid by Xcel Energy Inc. are allocated to its subsidiaries based on separate company computations. A similar allocation is made for state income taxes paid by Xcel Energy Inc. in connection with consolidated state filings. Xcel Energy Inc. also allocates its own income tax benefits to its direct subsidiaries. See Notes 4 and 7 for further information. Property, Plant and Equipment and Depreciation — Property, plant and equipment is stated at original cost. The cost of plant includes direct labor and materials, contracted work, overhead costs and AFUDC. The cost of plant retired is charged to accumulated depreciation and amortization. Amounts recovered in rates for future removal costs are recorded as regulatory liabilities. Significant additions or improvements extending asset lives are capitalized, while repairs and maintenance costs are charged to expense as incurred. Maintenance and replacement of items determined to be less than a unit of property are charged to operating expenses as incurred. Planned maintenance activities are charged to operating expense unless the cost represents the acquisition of an additional unit of property or the replacement of an existing unit of property. Property, plant and equipment is tested for impairment when it is determined that the carrying value of the assets may not be recoverable. A loss is recognized in the current period if it becomes probable that part of a cost of a plant under construction or recently completed plant will be disallowed for recovery from customers and a reasonable estimate of the disallowance can be made. For investments in property, plant and equipment that are abandoned and not expected to go into service, incurred costs and related deferred tax amounts are compared to the discounted estimated future rate recovery, and a loss is recognized, if necessary. SPS records depreciation expense using the straight-line method over the plant’s useful life. Actuarial life studies are performed and submitted to the state and federal commissions for review. Upon acceptance by the various commissions, the resulting lives and net salvage rates are used to calculate depreciation. Depreciation expense, expressed as a percentage of average depreciable property, was 2.9% in 2018, 2.8% in 2017, and 2.7% in 2016. See Note 3 for further information. AROs — SPS accounts for AROs under accounting guidance that requires a liability for the fair value of an ARO to be recognized in the period in which it is incurred if it can be reasonably estimated, with the offsetting associated asset retirement costs capitalized as a long-lived asset. The liability is generally increased over time by applying the effective interest method of accretion, and the capitalized costs are depreciated over the useful life of the long-lived asset. Changes resulting from revisions to the timing or amount of expected asset retirement cash flows are recognized as an increase or a decrease in the ARO. SPS also recovers through rates certain future plant removal costs in addition to AROs. The accumulated removal costs for these obligations are reflected in the balance sheets as a regulatory liability. See Note 10 for further information. Benefit Plans and Other Postretirement Benefits — SPS maintains pension and postretirement benefit plans for eligible employees. Recognizing the cost of providing benefits and measuring the projected benefit obligation of these plans requires management to make various assumptions and estimates. Certain unrecognized actuarial gains and losses and unrecognized prior service costs or credits are deferred as regulatory assets and liabilities, rather than recorded as other comprehensive income, based on regulatory recovery mechanisms. See Note 9 for further information. Environmental Costs — Environmental costs are recorded when it is probable SPS is liable for remediation costs and the liability can be reasonably estimated. Costs are deferred as a regulatory asset if it is probable that the costs will be recovered from customers in future rates. Otherwise, the costs are expensed. If an environmental expense is related to facilities currently in use, such as emission-control equipment, the cost is capitalized and depreciated over the life of the plant. Estimated remediation costs are regularly adjusted as estimates are revised and remediation proceeds. If other participating PRPs exist and acknowledge their potential involvement with a site, costs are estimated and recorded only for SPS’ expected share of the cost. Future costs of restoring sites are treated as a capitalized cost of plant retirement. The depreciation expense levels recoverable in rates include a provision for removal expenses. Removal costs recovered in rates before the related costs are incurred are classified as a regulatory liability. See Note 10 for further information. Revenue From Contracts With Customers — Performance obligations related to the sale of energy are satisfied as energy is delivered to customers. SPS recognizes revenue that corresponds to the price of the energy delivered to the customer. The measurement of energy sales to customers is generally based on the reading of their meters, which occurs on a systematic basis throughout the month. At the end of each month, amounts of energy delivered to customers since the date of the last meter reading are estimated, and the corresponding unbilled revenue is recognized. SPS does not recognize a separate financing component of its collections from customers as contract terms are short-term in nature. SPS presents its revenues net of any excise or sales taxes or fees. SPS participates in SPP. SPS recognizes sales to both native load and other end use customers on a gross basis in electric revenues and cost of sales. Revenues and charges for short term wholesale sales of excess energy transacted through RTOs are also recorded on a gross basis. Other revenues and charges related to participating and transacting in RTOs are recorded on a net basis in cost of sales. See Note 6 for further information. Cash and Cash Equivalents — SPS considers investments in instruments with a remaining maturity of three months or less at the time of purchase, to be cash equivalents. Accounts Receivable and Allowance for Bad Debts — Accounts receivable are stated at the actual billed amount net of an allowance for bad debts. SPS establishes an allowance for uncollectible receivables based on a policy that reflects its expected exposure to the credit risk of customers. As of Dec. 31, 2018 and 2017, the allowance for bad debts was $5.6 million and $6.3 million , respectively. Inventory — Inventory is recorded at average cost. As of Dec. 31, 2018, materials and supplies and fuel inventory were $25.7 million and $8.2 million , respectively. As of Dec. 31, 2017, materials and supplies and fuel inventory were $26.2 million and $14.2 million , respectively. Fair Value Measurements — SPS presents cash equivalents, interest rate derivatives and commodity derivatives at estimated fair values in its financial statements. Cash equivalents are recorded at cost plus accrued interest; money market funds are measured using quoted NAVs. For interest rate derivatives, quoted prices based primarily on observable market interest rate curves are used to establish fair value. For commodity derivatives, the most observable inputs available are generally used to determine the fair value of each contract. In the absence of a quoted price, SPS may use quoted prices for similar contracts or internally prepared valuation models to determine fair value. For the pension and postretirement plan assets published trading data and pricing models, generally using the most observable inputs available, are utilized to estimate fair value for each security. See Notes 8 and 9 for further information. Derivative Instruments — SPS uses derivative instruments in connection with its utility commodity price and interest rate activities, including forward contracts, futures, swaps and options. Any derivative instruments qualifying for the normal purchases and normal sales exception are recorded on the balance sheets at fair value as derivative instruments. Classification of changes in fair value for those derivative instruments is dependent on the designation of a qualifying hedging relationship. Changes in fair value of derivative instruments not designated in a qualifying hedging relationship are reflected in current earnings or as a regulatory asset or liability. Classification as a regulatory asset or liability is based on expected recovery of derivative instrument settlements through fuel and purchased energy cost recovery mechanisms. Interest rate hedging transactions are recorded as a component of interest expense. Normal Purchases and Normal Sales — SPS enters into contracts for purchases and sales of commodities for use in its operations. At inception, contracts are evaluated to determine whether a derivative exists and/or whether an instrument may be exempted from derivative accounting if designated as a normal purchase or normal sale. See Note 8 for further information. Other Utility Items AFUDC — AFUDC represents the cost of capital used to finance utility construction activity. AFUDC is computed by applying a composite financing rate to qualified CWIP. The amount of AFUDC capitalized as a utility construction cost is credited to other nonoperating income (for equity capital) and interest charges (for debt capital). AFUDC amounts capitalized are included in SPS’ rate base for establishing utility rates. Alternative Revenue — Certain rate rider mechanisms (including DSM programs) qualify as alternative revenue programs under GAAP. These mechanisms arise from costs imposed upon the utility by action of a regulator or legislative body related to an environmental, public safety or other mandate. When certain criteria are met, such as collection within 24 months , revenue is recognized equal to the revenue requirement, which may include incentives and return on rate base items. Billing amounts are revised periodically for differences between the total amount collected and the revenue earned, which may increase or decrease the level of revenue collected from customers. Alternative revenues arising from these programs are presented on a gross basis and disclosed separately from revenue from contracts with customers in the period earned. See Note 6 for further information. Conservation Programs — SPS has implemented programs in its jurisdictions to assist customers in conserving energy and reducing peak demand on the electric system. These programs include commercial motor, air conditioner and lighting upgrades, as well as residential rebates for participation in air conditioner interruption and home weatherization. The costs incurred for some DSM programs are deferred as permitted by the applicable regulatory jurisdiction. For those programs, costs are deferred if it is probable future revenue will be provided to permit recovery of the incurred cost. Revenues recognized for incentive programs designed for recovery of lost margins and/or conservation performance incentives are limited to amounts expected to be collected within 24 months from the annual period in which they are earned. SPS recovers approved conservation program costs in base rate revenue or through a rider. Emission Allowances — Emission allowances are recorded at cost plus broker commission fees. The inventory accounting model is utilized for all emission allowances and sales of these allowances are included in electric revenues. RECs — Cost of RECs that are utilized for compliance purposes is recorded as electric fuel and purchased power expense. SPS reduces recoverable fuel costs for the cost of RECs and records that cost as a regulatory asset when the amount is recoverable in future rates. Sales of RECs are recorded in electric revenues on a gross basis. The cost of these RECs and amounts credited to customers under margin-sharing mechanisms are recorded in electric fuel and purchased power expense. Segment Information — SPS has only one reportable segment. SPS is a wholly owned subsidiary of Xcel Energy Inc. and operates in the regulated electric utility industry providing wholesale and retail electric service in the states of Texas and New Mexico. Operating results from the regulated electric utility segment serve as the primary basis for the chief operating decision maker to evaluate the performance of SPS. |
Accounting Pronouncements
Accounting Pronouncements | 12 Months Ended |
Dec. 31, 2018 | |
New Accounting Pronouncements and Changes in Accounting Principles [Abstract] | |
Accounting Pronouncements | Accounting Pronouncements Recently Issued Leases — In 2016, the FASB issued Leases, Topic 842 (ASU No. 2016-02) , which requires balance sheet recognition of right-of-use assets and lease liabilities for most leases. Adoption will occur on Jan. 1, 2019 utilizing the package of transition practical expedients provided by the new standard, including carrying forward prior conclusions of whether agreements existing before the adoption date contain leases, and whether existing leases are operating or capital/finance leases. SPS expects to utilize other expedients offered by the new standard and Leases, Topic 842 (ASU No. 2018-11) , including elections to not recognize short term leases on the balance sheet for certain classes of assets and to implement the standard on a prospective basis. SPS’ implementation of the new guidance is substantially complete, and is expected to result in the recognition of right-of-use assets and lease liabilities in the first quarter of 2019 for operating leases for the use of real estate, equipment and certain natural gas generating facilities operated under PPAs. The implementation is not expected to have a significant impact on SPS’ financial statements, other than first-time recognition of these operating leases on the balance sheet. Recently Adopted Revenue Recognition — In 2014, the FASB issued Revenue from Contracts with Customers, Topic 606 (ASU No. 2014-09) , which provides a new framework for the recognition of revenue. SPS implemented the guidance on a modified retrospective basis on Jan. 1, 2018. Results for reporting periods beginning after Dec. 31, 2017 are presented in accordance with Topic 606, while prior period results have not been adjusted and continue to be reported in accordance with prior accounting guidance. The implementation did not have a material impact on SPS’ financial statements, other than increased disclosures regarding revenues related to contracts with customers. Classification and Measurement of Financial Instruments — In 2016, the FASB issued Recognition and Measurement of Financial Assets and Financial Liabilities, Subtopic 825-10 (ASU No. 2016-01) , which eliminated the available-for-sale classification for marketable equity securities and also replaced the cost method of accounting for non-marketable equity securities with a model for recognizing impairments and observable price changes. SPS implemented the guidance on Jan. 1, 2018 and the adoption impacts were not material. Presentation of Net Periodic Benefit Cost — In 2017, the FASB issued Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, Topic 715 (ASU No. 2017-07) , which establishes that only the service cost portion of pension cost may be presented as a component of operating income. In addition, only the service cost portion of pension cost is eligible for capitalization. As a result of regulatory accounting treatment, a similar amount of pension cost, including non-service components, will be recognized consistent with historical ratemaking and the impacts of adoption are limited to changes in classification of non-service costs in the statement of income. SPS implemented the new guidance on Jan. 1, 2018. As a result, $4.1 million and $4.0 million of pension costs were retrospectively reclassified from operating and maintenance expenses to other expense, net on the income statement for 2017 and 2016, respectively. SPS used benefit cost amounts disclosed for prior periods as the basis for retrospective application. |
Property Plant and Equipment Pr
Property Plant and Equipment Property Plant and Equipment | 12 Months Ended |
Dec. 31, 2018 | |
Property, Plant and Equipment [Abstract] | |
Property, Plant and Equipment Disclosure | Property, Plant and Equipment Major classes of property, plant and equipment: (Millions of Dollars) Dec. 31, 2018 Dec. 31, 2017 Property, plant and equipment Electric plant $ 7,227.7 $ 6,765.3 CWIP 847.3 351.9 Total property, plant and equipment 8,075.0 7,117.2 Less accumulated depreciation (2,128.6 ) (2,021.6 ) $ 5,946.4 $ 5,095.6 |
Regulatory Assets and Liabiliti
Regulatory Assets and Liabilities | 12 Months Ended |
Dec. 31, 2018 | |
Regulatory Assets and Liabilities Disclosure [Abstract] | |
Regulatory Assets and Liabilities | Regulatory Assets and Liabilities Regulatory assets and liabilities are created for amounts that regulators may allow to be collected, or may require to be paid back to customers in future electric rates. SPS would be required to recognize the write-off of regulatory assets and liabilities in net income or other comprehensive income if changes in the utility industry no longer allow for the application of regulatory accounting guidance under GAAP. Components of regulatory assets: (Millions of Dollars) See Remaining Dec. 31, 2018 Dec. 31, 2017 Regulatory Assets Current Noncurrent Current Noncurrent Pension and retiree medical obligations 9 Various $ 12.6 $ 222.1 $ 12.7 $ 223.0 Excess deferred taxes - TCJA 7 Various — 55.9 — 44.7 Recoverable deferred taxes on AFUDC recorded in plant Plant lives — 27.9 — 23.9 Net AROs (a) 1, 10 Plant lives — 25.7 — 24.2 Losses on reacquired debt Term of related debt 0.8 21.9 0.8 22.7 Conservation programs (b) 1 One to two years 0.7 0.6 2.7 0.7 Other Various 11.9 12.1 15.3 23.7 Total regulatory assets $ 26.0 $ 366.2 $ 31.5 $ 362.9 (a) Includes amounts recorded for future recovery of AROs. (b) Includes costs for conservation programs, as well as incentives allowed in certain jurisdictions. Components of regulatory liabilities: (Millions of Dollars) See Remaining Dec. 31, 2018 Dec. 31, 2017 Regulatory Liabilities Current Noncurrent Current Noncurrent Deferred income tax adjustments and TCJA refunds (a) 7 Various $ 2.2 $ 569.8 $ — $ 568.6 Plant removal costs 1, 10 Plant lives — 187.7 — 196.9 Revenue subject to refund One to two years 11.3 8.1 6.8 6.5 Gain from asset sales Various — 2.4 — 2.5 Deferred electric energy costs Less than one year 56.5 — 48.5 — Contract valuation adjustments (b) 1, 8 Less than one year 14.7 — 12.7 — Other Various 1.1 12.9 0.8 10.1 Total regulatory liabilities $ 85.8 $ 780.9 $ 68.8 $ 784.6 (a) Includes the revaluation of recoverable/regulated plant ADIT and revaluation impact of non-plant ADIT due to the TCJA. (b) Includes the fair value of certain long-term PPAs used to meet energy capacity requirements. At Dec. 31, 2018 and 2017 , approximately $48 million and $64 million , respectively, of SPS’ regulatory assets represented past expenditures not earning a return. Amounts primarily related to formula rates, losses on reacquired debt and certain rate case expenditures. |
Borrowings and Other Financing
Borrowings and Other Financing Instruments | 12 Months Ended |
Dec. 31, 2018 | |
Debt Disclosure [Abstract] | |
Borrowings and Other Financing Instruments | Borrowings and Other Financing Instruments Short-Term Borrowings Money Pool — Xcel Energy Inc. and its utility subsidiaries have established a money pool arrangement that allows for short-term investments in and borrowings between the utility subsidiaries. Xcel Energy Inc. may make investments in the utility subsidiaries at market-based interest rates; however, the money pool arrangement does not allow the utility subsidiaries to make investments in Xcel Energy Inc. Money pool borrowings for SPS were as follows: Three Months Ended Dec. 31, 2018 Year Ended Dec. 31 (Amounts in Millions, Except Interest Rates) 2018 2017 2016 Borrowing limit $ 100 $ 100 $ 100 $ 100 Amount outstanding at period end — — — — Average amount outstanding 14 29 13 28 Maximum amount outstanding 74 100 100 100 Weighted average interest rate, computed on a daily basis 2.13 % 1.96 % 1.12 % 0.67 % Weighted average interest rate at end of period N/A N/A N/A N/A Commercial Paper — SPS meets its short-term liquidity requirements primarily through the issuance of commercial paper and borrowings under its credit facility. Commercial paper outstanding for SPS was as follows: Three Months Ended Dec. 31, 2018 Year Ended Dec. 31 (Amounts in Millions, Except Interest Rates) 2018 2017 2016 Borrowing limit $ 400 $ 400 $ 400 $ 400 Amount outstanding at period end 42 42 — 50 Average amount outstanding 20 30 69 43 Maximum amount outstanding 100 144 176 140 Weighted average interest rate, computed on a daily basis 2.45 % 2.27 % 1.13 % 0.67 % Weighted average interest rate at end of period 2.80 2.80 NA 0.95 Letters of Credit — SPS may use letters of credit, typically with terms of one -year, to provide financial guarantees for certain operating obligations. At Dec. 31, 2018 and 2017, there were $2 million and $3 million of letters of credit outstanding, respectively, under the credit facility. Amounts approximate their fair value. Credit Facility — In order to use its commercial paper program to fulfill short-term funding needs, SPS must have a revolving credit facility in place at least equal to the amount of its commercial paper borrowing limit and cannot issue commercial paper in an aggregate amount exceeding available capacity under this credit facility. The line of credit provides short-term financing in the form of notes payable to banks, letters of credit and back-up support for commercial paper borrowings. Features of SPS’ credit facility: Debt-to-Total Capitalization Ratio (a) Amount Facility May Be Increased (millions) Additional Periods For Which a One-Year Extension May Be Requested (b) 2018 2017 46% 46% $50 2 (a) The SPS credit facility has a financial covenant requiring that the debt-to-total capitalization ratio be less than or equal to 65% . (b) All extension requests are subject to majority bank group approval. The credit facility has a cross-default provision that SPS will be in default on its borrowings under the facility if SPS or any of its future significant subsidiaries whose total assets exceed 15% of SPS’ total assets default on indebtedness in an aggregate principal amount exceeding $75 million . If SPS does not comply with the covenant, an event of default may be declared, and if not remedied, any outstanding amounts due under the facility can be declared due by the lender. As of Dec. 31, 2018, SPS was in compliance with all financial covenants. SPS had the following committed credit facilities available as of Dec. 31, 2018 . Credit Facility (a) Drawn (b) Available $400 $44 $356 (a) This credit facility matures in June 2021 . (b) Includes letters of credit and outstanding commercial paper. All credit facility bank borrowings, outstanding letters of credit and outstanding commercial paper reduce the available capacity under the credit facility. SPS had no direct advances on the facility outstanding at Dec. 31, 2018 and 2017 . Long-Term Borrowings and Other Financing Instruments Generally, all property of SPS is subject to the lien of its first mortgage indenture. Debt premiums, discounts and expenses are amortized over the life of the related debt. The premiums, discounts and expenses for refinanced debt are deferred and amortized over the life of the new issuance. Long term debt obligations for SPS as of Dec. 31: (Millions of Dollars) Maturity Range Interest Rate Range 2018 Interest Rate Range 2017 2018 2017 Mortgage bonds 2024 - 2048 3.30% - 4.50% 3.30% - 4.50% $ 1,800 $ 1,500 Unsecured senior notes 2033 - 2036 6.00% 6.00% - 8.75% 350 350 Unamortized discount (4 ) (2 ) Unamortized debt issuance cost (20 ) (18 ) Current maturities — — Total long term debt $ 2,126 $ 1,830 During the next five years, SPS has no long term debt maturities. Deferred Financing Costs — Deferred financing costs of approximately $20 million and $18 million , net of amortization, are presented as a deduction from the carrying amount of long-term debt at Dec. 31, 2018 and 2017 , respectively. SPS is amortizing these financing costs over the remaining maturity periods of the related debt. 2018 financings: Amount Financing Instrument Interest Rate Maturity Date $300 million First mortgage bonds 4.40 % Nov 15, 2048 2017 financings: Amount Financing Instrument Interest Rate Maturity Date $450 million First mortgage bonds 3.70 % Aug 15, 2047 Capital Stock — SPS has the following preferred stock: Preferred Stock Authorized (Shares) Par Value of Preferred Stock Preferred Stock Outstanding (Shares) 2018 and 2017 SPS 10,000,000 1.00 0 Dividend Restrictions — SPS dividends are subject to the FERC’s jurisdiction, which prohibits the payment of dividends out of capital accounts. Dividends are solely to be paid from retained earnings. SPS is required to be current on particular interest payments before dividends can be paid. SPS’ state regulatory commission imposes the most restrictive dividend limitations. Requirements and actuals as of Dec. 31, 2018: Equity to Total Capitalization Ratio - Required Range Equity to Total Capitalization Ratio - Actual (a) Low High 2018 45.0 % 55.0 % 54.4 % (a) SPS excludes short-term debt. Unrestricted Retained Earnings Total Capitalization Limit on Total Capitalization 2018 2018 2018 SPS (a) $ 605.7 million $ 4.7 billion N/A (a) SPS may not pay a dividend that would cause it to lose its investment grade bond rating. |
Revenues
Revenues | 12 Months Ended |
Dec. 31, 2018 | |
Revenue from Contract with Customer [Abstract] | |
Revenue from Contract with Customer [Text Block] | Revenues Revenue is classified by the type of goods/services rendered and market/customer type. SPS’ operating revenues (subsequent to adoption of the revised revenue guidance) consists of the following: (Millions of Dollars) Year Ended Dec. 31, 2018 Major product lines Revenue from contracts with customers: Residential $ 363.7 C&I 828.3 Other 44.7 Total retail 1,236.7 Wholesale 426.0 Transmission 231.1 Other 12.8 Total revenue from contracts with customers 1,906.6 Alternative revenue and other 26.6 Total revenues $ 1,933.2 |
Income Taxes
Income Taxes | 12 Months Ended |
Dec. 31, 2018 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | Income Taxes Federal Tax Reform — In 2017, the TCJA was signed into law. The key provisions impacting Xcel Energy (which includes SPS), generally beginning in 2018, include: • Corporate federal tax rate reduction from 35% to 21% ; • Normalization of resulting plant-related excess deferred taxes; • Elimination of the corporate alternative minimum tax; • Continued interest expense deductibility and discontinued bonus depreciation for regulated public utilities; • Limitations on certain executive compensation deductions; • Limitations on certain deductions for NOLs arising after Dec. 31, 2017 (limited to 80% of taxable income); • Repeal of the section 199 manufacturing deduction; and, • Reduced deductions for meals and entertainment as well as state and local lobbying. Xcel Energy estimated the effects of the TCJA, which have been reflected in the consolidated financial statements. Reductions in deferred tax assets and liabilities due to a decrease in corporate federal tax rates typically result in a net tax benefit. However, the impacts are primarily recognized as regulatory liabilities refundable to utility customers as a result of IRS requirements and past regulatory treatment. Estimated impacts of the new tax law for SPS in December 2017 included: • $426 million ( $559 million grossed-up for tax) of reclassifications of plant-related excess deferred taxes to regulatory liabilities upon valuation at the new 21% federal rate. The regulatory liabilities will be amortized consistent with IRS normalization requirements, resulting in customer refunds over the average remaining life of the related property; • $45 million and $28 million of reclassifications (grossed-up for tax) of excess deferred taxes for non-plant related deferred tax assets and liabilities, respectively, to regulatory assets and liabilities; and, • $8 million of total estimated income tax benefit related to the federal tax reform implementation, and a $2 million reduction to net income related to the allocation of Xcel Energy Services Inc.’s tax rate change on its deferred taxes. Xcel Energy accounted for the state tax impacts of federal tax reform based on enacted state tax laws. Any future state tax law changes related to the TCJA will be accounted for in the periods state laws are enacted. Federal Audit — SPS is a member of the Xcel Energy affiliated group that files a consolidated federal income tax return. Statute of limitations applicable to Xcel Energy’s consolidated federal income tax returns expire as follows: Tax Year(s) Expiration 2009 - 2014 October 2019 2015 September 2019 2016 September 2020 2017 September 2021 In 2012, the IRS commenced an examination of tax years 2010 and 2011 , including the 2009 carryback claim. In 2017, Xcel Energy and the Office of Appeals reached an agreement and the benefit related to the agreed upon portions was recognized. SPS did not accrue any income tax benefit related to this adjustment. In the second quarter of 2018, the Joint Committee on Taxation completed its review and took no exception to the agreement. As a result, the remaining unrecognized tax benefit was released and recorded as a payable to the IRS. In the third quarter of 2015, the IRS commenced an examination of tax years 2012 and 2013 . In the third quarter of 2017, the IRS concluded the audit of tax years 2012 and 2013 and proposed an adjustment that would impact Xcel Energy’s NOL and ETR. Xcel Energy filed a protest with the IRS. As of Dec. 31, 2018, the case has been forwarded to the Office of Appeals and Xcel Energy has recognized its best estimate of income tax expense that will result from a final resolution of this issue; however, the outcome and timing of a resolution is unknown. In the fourth quarter of 2018, the IRS began an audit of tax years 2014 - 2016 , however no adjustments have been proposed. State Audits — SPS is a member of the Xcel Energy affiliated group that files consolidated state income tax returns. As of Dec. 31, 2018, SPS’ earliest open tax year that is subject to examination by state taxing authorities under applicable statutes of limitations is 2010 . There are currently no state income tax audits in progress. Unrecognized Tax Benefits — Unrecognized tax benefit balance includes permanent tax positions, which if recognized would affect the annual ETR. In addition, the unrecognized tax benefit balance includes temporary tax positions for which the ultimate deductibility is highly certain, but for which there is uncertainty about the timing of such deductibility. A change in the period of deductibility would not affect the ETR but would accelerate the payment to the taxing authority to an earlier period. Unrecognized tax benefits - permanent vs temporary: (Millions of Dollars) Dec. 31, 2018 Dec. 31, 2017 Unrecognized tax benefit — Permanent tax positions $ 3.0 $ 2.3 Unrecognized tax benefit — Temporary tax positions 1.5 2.0 Total unrecognized tax benefit $ 4.5 $ 4.3 Changes in unrecognized tax benefits: (Millions of Dollars) 2018 2017 2016 Balance at Jan. 1 $ 4.3 $ 28.7 $ 24.7 Additions based on tax positions related to the current year 0.6 0.9 1.4 Reductions based on tax positions related to the current year (0.1 ) (0.6 ) — Additions for tax positions of prior years 0.1 1.3 3.9 Reductions for tax positions of prior years (0.3 ) (19.9 ) (1.3 ) Settlements with taxing authorities (0.1 ) (6.1 ) — Balance at Dec. 31 $ 4.5 $ 4.3 $ 28.7 Unrecognized tax benefits were reduced by tax benefits associated with NOL and tax credit carryforwards: (Millions of Dollars) Dec. 31, 2018 Dec. 31, 2017 NOL and tax credit carryforwards $ (3.8 ) $ (5.9 ) Net deferred tax liability associated with the unrecognized tax benefit amounts and related NOLs and tax credits carryforwards were $0.8 million and $2.7 million at Dec. 31, 2018 and Dec. 31, 2017, respectively. As the IRS Appeals and federal audit progress and state audits resume, it is reasonably possible that the amount of unrecognized tax benefit could decrease up to approximately $3.6 million in the next 12 months. Payable for interest related to unrecognized tax benefits is partially offset by the interest benefit associated with NOL and tax credit carryforwards. Interest payable related to unrecognized tax benefits: (Millions of Dollars) 2018 2017 2016 Receivable (payable) for interest related to unrecognized tax benefits at Jan. 1 $ 0.5 $ (0.9 ) $ — Interest income (expense) related to unrecognized tax benefits 0.2 1.4 (0.9 ) Receivable (payable) for interest related to unrecognized tax benefits at Dec. 31 $ 0.7 $ 0.5 $ (0.9 ) No amounts were accrued for penalties related to unrecognized tax benefits as of Dec. 31, 2018, 2017, or 2016. Other Income Tax Matters — NOL amounts represent the tax loss that is carried forward and tax credits represent the deferred tax asset. NOL and tax credit carryforwards as of Dec. 31 were as follows: (Millions of Dollars) 2018 2017 Federal NOL carryforward $ — $ 115.0 Federal tax credit carryforwards 5.7 5.2 State NOL carryforwards 2.9 40.5 Federal carryforward periods expire between 2021 and 2038 and state carryforward periods expire between 2021 and 2036 . Total income tax expense from operations differs from the amount computed by applying the statutory federal income tax rate to income before income tax expense. Effective income tax rate for years ended Dec. 31: 2018 2017 (a) 2016 (a) Federal statutory rate 21.0 % 35.0 % 35.0 % State income tax on pretax income, net of federal tax effect 2.3 % 2.0 % 2.2 % Increases (decreases) in tax from: Regulatory differences - ARAM (b) (4.2 ) — — Tax Reform — (3.5 ) — Adjustments attributable to tax returns (1.5 ) (0.4 ) (1.1 ) Regulatory differences - other utility plant items (1.3 ) (0.8 ) (1.0 ) Amortization of excess nonplant deferred taxes (1.2 ) — — Tax credits recognized, net of federal income tax expense (0.7 ) (0.7 ) (0.5 ) Regulatory differences - Deferral of ARAM (c) 0.7 — — Change in unrecognized tax benefits 0.1 (1.0 ) 0.8 Other, net 0.2 (0.5 ) (0.4 ) Effective income tax rate 15.4 % 30.1 % 35.0 % (a) Prior periods have been reclassified to conform to current year presentation. (b) ARAM is a method to flow back excess deferred taxes to customers. (c) ARAM has been deferred when regulatory treatment has not been established. As Xcel Energy received direction from its regulatory commissions regarding the return of excess deferred taxes to customers, the ARAM deferral was reversed. This resulted in a reduction to tax expense with a corresponding reduction to revenue. Components of income tax expense for years ended Dec. 31: (Millions of Dollars) 2018 2017 2016 Current federal tax expense (benefit) $ 12.3 $ (20.9 ) $ (40.9 ) Current state tax expense (benefit) 2.3 (12.8 ) (2.9 ) Current change in unrecognized tax expense (benefit) 2.3 (24.3 ) 3.1 Deferred federal tax expense 20.5 89.9 116.4 Deferred state tax expense 3.6 14.5 7.8 Deferred change in unrecognized tax (benefit) expense (2.0 ) 22.1 (1.2 ) Deferred ITCs (0.1 ) (0.1 ) (0.2 ) Total income tax expense $ 38.9 $ 68.4 $ 82.1 Components of deferred income tax expense as of Dec. 31: (Millions of Dollars) 2018 2017 2016 Deferred tax expense (benefit) excluding items below $ 44.2 $ (414.2 ) $ 128.4 Amortization and adjustments to deferred income taxes on income tax regulatory assets and liabilities (22.0 ) 540.7 (5.4 ) Tax (expense) benefit allocated to other comprehensive income, net of adoption of ASU No. 2018-02, and other (0.1 ) — — Deferred tax expense $ 22.1 $ 126.5 $ 123.0 Components of the net deferred tax liability as of Dec. 31: (Millions of Dollars) 2018 2017 Deferred tax liabilities: Differences between book and tax bases of property $ 680.6 $ 654.4 Regulatory assets 49.2 46.8 Pension expense 32.3 33.8 Other 2.9 4.6 Total deferred tax liabilities $ 765.0 $ 739.6 Deferred tax assets: Regulatory liabilities 116.8 114.6 NOL carryforward 0.2 26.2 Deferred fuel costs 12.7 10.4 Other employee benefits 5.6 5.8 Tax credit carryforward 5.7 5.2 Other 4.9 2.5 Total deferred tax assets $ 145.9 $ 164.7 Net deferred tax liability $ 619.1 $ 574.9 |
Fair Value of Financial Assets
Fair Value of Financial Assets and Liabilities | 12 Months Ended |
Dec. 31, 2018 | |
Fair Value Disclosures [Abstract] | |
Fair Value of Financial Assets and Liabilities | 8. Fair Value of Financial Assets and Liabilities Fair Value Measurements The accounting guidance for fair value measurements and disclosures provides a single definition of fair value and requires disclosures about assets and liabilities measured at fair value. A hierarchical framework for disclosing the observability of the inputs utilized in measuring assets and liabilities at fair value is established by this guidance. • Level 1 — Quoted prices are available in active markets for identical assets or liabilities as of the reporting date. The types of assets and liabilities included in Level 1 are highly liquid and actively traded instruments with quoted prices. • Level 2 — Pricing inputs are other than quoted prices in active markets, but are either directly or indirectly observable as of the reporting date. The types of assets and liabilities included in Level 2 are typically either comparable to actively traded securities or contracts, or priced with models using highly observable inputs. • Level 3 — Significant inputs to pricing have little or no observability as of the reporting date. The types of assets and liabilities included in Level 3 are those valued with models requiring significant management judgment or estimation. Specific valuation methods include: Cash equivalents — The fair values of cash equivalents are generally based on cost plus accrued interest; money market funds are measured using quoted NAVs. Interest rate derivatives — The fair values of interest rate derivatives are based on broker quotes that utilize current market interest rate forecasts. Commodity derivatives — The methods used to measure the fair value of commodity derivative forwards and options utilize forward prices and volatilities, as well as pricing adjustments for specific delivery locations, and are generally assigned a Level 2 classification. When contractual settlements relate to inactive delivery locations or extend to periods beyond those readily observable on active exchanges or quoted by brokers, the significance of the use of less observable forecasts of forward prices and volatilities on a valuation is evaluated, and may result in Level 3 classification. Electric commodity derivatives held by SPS include transmission congestion instruments, generally referred to as FTRs, purchased from SPP. FTRs purchased from an RTO are financial instruments that entitle or obligate the holder to monthly revenues or charges based on transmission congestion across a given transmission path. The value of an FTR is derived from, and designed to offset, the cost of transmission congestion. In addition to overall transmission load, congestion is also influenced by the operating schedules of power plants and the consumption of electricity pertinent to a given transmission path. Unplanned plant outages, scheduled plant maintenance, changes in the relative costs of fuels used in generation, weather and overall changes in demand for electricity can each impact the operating schedules of the power plants on the transmission grid and the value of an FTR. If forecasted costs of electric transmission congestion increase or decrease for a given FTR path, the value of that particular FTR instrument will likewise increase or decrease. Given the limited observability of important inputs to the value of FTRs between auction processes, including expected plant operating schedules and retail and wholesale demand, fair value measurements for FTRs have been assigned a Level 3. Non-trading monthly FTR settlements are expected to be recovered through fuel and purchased energy cost recovery mechanisms, and therefore changes in the fair value of the yet to be settled portions of FTRs are deferred as a regulatory asset or liability. Given this regulatory treatment and the limited magnitude of FTRs relative to the electric utility operations of SPS, the numerous unobservable quantitative inputs pertinent to the value of FTRs are insignificant to the financial statements of SPS. Derivative Fair Value Measurements SPS enters into derivative instruments, including forward contracts, for trading purposes and to manage risk in connection with changes in interest rates and electric utility commodity prices. Interest Rate Derivatives — SPS may enter into various instruments that effectively fix the interest payments on certain floating rate debt obligations or effectively fix the yield or price on a specified benchmark interest rate for an anticipated debt issuance for a specific period. These derivative instruments are generally designated as cash flow hedges for accounting purposes. As of Dec. 31, 2018, accumulated other comprehensive losses related to interest rate derivatives included $0.1 million net losses expected to be reclassified into earnings during the next 12 months as the related hedged interest rate transactions impact earnings, including forecasted amounts for unsettled hedges, as applicable. Wholesale and Commodity Trading Risk — SPS conducts various wholesale and commodity trading activities, including the purchase and sale of electric capacity, energy and energy-related instruments, including derivatives. SPS is allowed to conduct these activities within guidelines and limitations as approved by its risk management committee, comprised of management personnel not directly involved in the activities governed by this policy. Commodity Derivatives — SPS enters into derivative instruments to manage variability of future cash flows from changes in commodity prices in its electric utility operations. This could include the purchase or sale of energy or energy-related products and FTRs. Gross notional amounts of commodity FTRs at Dec. 31, 2018 and 2017: (Amounts in Millions) (a) Dec. 31, 2018 Dec. 31, 2017 MWh of electricity 5.5 4.3 (a) amounts are not reflective of net positions in the underlying commodities. Consideration of Credit Risk and Concentrations — SPS continuously monitors the creditworthiness of counterparties to its interest rate derivatives and commodity derivative contracts prior to settlement, and assesses each counterparty’s ability to perform on the transactions set forth in the contracts. Impact of credit risk was immaterial to the fair value of unsettled commodity derivatives presented in the balance sheets. SPS’ most significant concentrations of credit risk with particular entities or industries are contracts with counterparties to its wholesale, trading and non-trading commodity activities. At Dec. 31, 2018, two of the eight most significant counterparties for these activities, comprising $11.6 million or 28% of this credit exposure, had investment grade ratings from Standard & Poor’s, Moody’s or Fitch Ratings. Five of the eight most significant counterparties, comprising $8.7 million or 21% of this credit exposure, were not rated by external rating agencies, but based on SPS’ internal analysis, had credit quality consistent with investment grade. Another of these significant counterparties, comprising $0.6 million or less than 1% of this credit exposure, had credit quality less than investment grade, based on external analysis. Six of these significant counterparties are municipal or cooperative electric entities, or other utilities. Qualifying Cash Flow Hedges — Financial impact of qualifying interest rate cash flow hedges on SPS’ accumulated other comprehensive loss, included in the statements of common stockholder’s equity and in the statements of comprehensive income: (Millions of Dollars) 2018 2017 2016 Accumulated other comprehensive loss related to cash flow hedges at Jan. 1 $ (0.8 ) $ (0.7 ) $ (0.8 ) After-tax net realized losses on derivative transactions reclassified into earnings 0.1 — 0.1 Adoption of ASU. 2018-02 (a) — (0.1 ) — Accumulated other comprehensive loss related to cash flow hedges at Dec. 31 $ (0.7 ) $ (0.8 ) $ (0.7 ) (a) In 2017, SPS implemented ASU No. 2018-02 related to TCJA, which resulted in reclassification of certain credit balances within net accumulated other comprehensive loss to retained earnings. Pre-tax losses related to interest rate derivatives reclassified from accumulated other comprehensive loss into earnings were $0.1 million , $0.1 million and $0.2 million for the years ended Dec. 31, 2018, 2017 and 2016, respectively. Changes in the fair value of FTRs resulting in pre-tax net gains of $7.0 million , $0.5 million and $3.0 million recognized for the years ended Dec. 31, 2018, 2017 and 2016, respectively, were reclassified as regulatory assets and liabilities. The classification as a regulatory asset or liability is based on expected recovery of FTR settlements through fuel and purchased energy cost recovery mechanisms. FTR settlement gains of $4.4 million , $0.8 million and $2.1 million were recognized for the years ended Dec. 31, 2018, 2017 and 2016, respectively, and were recorded to electric fuel and purchased power. These derivative settlement gains and losses are shared with electric customers through fuel and purchased energy cost-recovery mechanisms, and reclassified out of income as regulatory assets or liabilities, as appropriate. SPS had no derivative instruments designated as fair value hedges during the years ended Dec. 31, 2018, 2017 and 2016. Recurring Fair Value Measurements — The following table presents for each of the fair value hierarchy levels, SPS’ derivative assets and liabilities measured at fair value on a recurring basis at Dec. 31, 2018 and 2017: Dec. 31, 2018 Dec. 31, 2017 Fair Value Fair Value (Millions of Dollars) Level 1 Level 2 Level 3 Fair Value Total Netting (a) Total Level 1 Level 2 Level 3 Fair Value Total Netting (a) Total Current derivative assets Other derivative instruments: Electric commodity $ — $ — $ 14.9 $ 14.9 $ (0.2 ) $ 14.7 $ — $ — $ 14.7 $ 14.7 $ (2.0 ) $ 12.7 Total current derivative assets $ — $ — $ 14.9 $ 14.9 $ (0.2 ) 14.7 $ — $ — $ 14.7 $ 14.7 $ (2.0 ) 12.7 PPAs (b) 3.1 3.2 Current derivative instruments $ 17.8 $ 15.9 Noncurrent derivative assets PPAs (b) 15.8 19.0 Noncurrent derivative instruments $ 15.8 $ 19.0 Current derivative liabilities Other derivative instruments: Electric commodity $ — $ — $ 0.2 $ 0.2 $ (0.2 ) $ — $ — $ — $ 2.0 $ 2.0 $ (2.0 ) $ — Total current derivative liabilities $ — $ — $ 0.2 $ 0.2 $ (0.2 ) — $ — $ — $ 2.0 $ 2.0 $ (2.0 ) — PPAs (b) 3.6 3.6 Current derivative instruments $ 3.6 $ 3.6 Noncurrent derivative liabilities PPAs (b) 16.4 19.9 Noncurrent derivative instruments $ 16.4 $ 19.9 (a) SPS nets derivative instruments and related collateral in its balance sheet when supported by a legally enforceable master netting agreement, and all derivative instruments and related collateral amounts were subject to master netting agreements at Dec. 31, 2018 and 2017. At both Dec. 31, 2018 and 2017, derivative assets and liabilities include no obligations to return cash collateral or rights to reclaim cash collateral. The counterparty netting excludes settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements. (b) During 2006, SPS qualified these contracts under the normal purchase exception. Based on this qualification, the contracts are no longer adjusted to fair value and the previous carrying value of these contracts will be amortized over the remaining contract lives along with the offsetting regulatory assets and liabilities. Changes in Level 3 commodity derivatives for the years ended Dec. 31, 2018, 2017 and 2016: Year Ended Dec. 31 (Millions of Dollars) 2018 2017 2016 Balance at Jan. 1 $ 12.7 $ 2.0 $ 5.1 Purchases 32.3 41.2 7.6 Settlements (41.6 ) (55.8 ) (41.9 ) Net transactions recorded during the period: Net gains recognized as regulatory assets 11.3 25.3 31.2 Balance at Dec. 31 $ 14.7 $ 12.7 $ 2.0 SPS recognizes transfers between levels as of the beginning of each period. There were no transfers of amounts between levels for derivative instruments for 2016 - 2018. Fair Value of Long-Term Debt As of Dec. 31, other financial instruments for which the carrying amount did not equal fair value: 2018 2017 (Millions of Dollars) Carrying Amount Fair Value Carrying Amount Fair Value Long-term debt, including current portion $ 2,126.1 $ 2,139.8 $ 1,829.9 $ 2,002.0 Fair value of SPS’ long-term debt is estimated based on recent trades and observable spreads from benchmark interest rates for similar securities. Fair value estimates are based on information available to management as of Dec. 31, 2018 and 2017 , and given the observability of the inputs, fair values presented for long-term debt were assigned as Level 2. |
Benefit Plans and Other Postret
Benefit Plans and Other Postretirement Benefits | 12 Months Ended |
Dec. 31, 2018 | |
Retirement Benefits [Abstract] | |
Benefit Plans and Other Postretirement Benefits | Benefit Plans and Other Postretirement Benefits Xcel Energy, which includes SPS, has several noncontributory, defined benefit pension plans that cover almost all employees. Generally, benefits are based on a combination of years of service and average pay. Xcel Energy’s policy is to fully fund into an external trust the actuarially determined pension costs subject to the limitations of applicable employee benefit and tax laws. In addition to the qualified pension plans, Xcel Energy maintains a SERP and a nonqualified pension plan. The SERP is maintained for certain executives that were participants in the plan in 2008, when the SERP was closed to new participants. The nonqualified pension plan provides benefits for compensation that is in excess of the limits applicable to the qualified pension plans, with distributions funded by Xcel Energy’s consolidated operating cash flows. Obligations of the SERP and nonqualified plan as of Dec. 31, 2018 and 2017 were $33 million and $37 million , respectively, of which $2 million was attributable to SPS in 2018 and 2017. In 2018 and 2017, Xcel Energy recognized net benefit cost for the SERP and nonqualified plans of $4 million and $5 million , respectively, of which immaterial amounts were attributable to SPS. In 2016, Xcel Energy established rabbi trusts to provide partial funding for future distributions of the SERP and its deferred compensation plan. Rabbi trust funding of deferred compensation plan distributions attributable to SPS will be supplemented by SPS’s operating cash flows. Xcel Energy has a contributory health and welfare benefit plan that provides health care and death benefits to certain Xcel Energy retirees. • Xcel Energy discontinued health care benefits for SPS bargaining employees hired after Jan. 1, 2012. • Xcel Energy discontinued subsidizing health care benefits for nonbargaining employees of the former NCE, which includes SPS employees, who retired after June 30, 2003. Xcel Energy, which includes SPS, bases the investment-return assumption on expected long-term performance for each of the asset classes in its pension and postretirement health care portfolios. For pension assets, Xcel Energy considers the historical returns achieved by its asset portfolio over the past 20 years or longer period, as well as long-term projected return levels. Xcel Energy and SPS continually review pension assumptions. Pension cost determination assumes a forecasted mix of investment types over the long-term. • Investment returns in 2018 were below the assumed level of 6.78% ; • Investment returns in 2017 were above the assumed level of 6.78% ; • Investment returns in 2016 were below the assumed level of 6.78% ; and, • In 2019, Xcel Energy’s expected investment-return assumption is 6.78% . Pension plan and postretirement benefit assets are invested in a portfolio according to Xcel Energy’s return, liquidity and diversification objectives to provide a source of funding for plan obligations and minimize contributions to the plan, within appropriate levels of risk. The principal mechanism for achieving these objectives is the asset allocation given the long-term risk, return, correlation and liquidity characteristics of each particular asset class. There were no significant concentrations of risk in any industry, index, or entity. Market volatility can impact even well-diversified portfolios and significantly affect the return levels achieved by the assets in any year. State agencies also have issued guidelines to the funding of postretirement benefit costs. SPS is required to fund postretirement benefit costs for Texas and New Mexico amounts collected in rates. These assets are invested in a manner consistent with the investment strategy for the pension plan. Xcel Energy’s ongoing investment strategy is based on plan-specific investment recommendations that seek to minimize potential investment and interest rate risk as a plan’s funded status increases over time. The investment recommendations result in a greater percentage of long-duration fixed income securities being allocated to specific plans having relatively higher funded status ratios and a greater percentage of growth assets being allocated to plans having relatively lower funded status ratios. Pension Plan Assets The following presents, for each of the fair value hierarchy levels, SPS’ pension plan assets measured at fair value: Dec. 31, 2018 Dec. 31, 2017 (Millions of Dollars) Level 1 Level 2 Level 3 Measured at NAV Total Level 1 Level 2 Level 3 Measured at NAV Total Cash equivalents $ 21.6 $ — $ — $ — $ 21.6 26.9 — — — $ 26.9 Commingled funds: 128.6 — — 132.5 261.1 145.7 — — 142.7 288.4 Debt securities: — 98.1 — — 98.1 — 105.3 — — 105.3 Equity securities: 14.4 — — — 14.4 15.2 — — — 15.2 Other 0.2 0.8 — (4.0 ) (3.0 ) (3.3 ) 0.6 — 0.1 (2.6 ) Total $ 164.8 $ 98.9 $ — $ 128.5 $ 392.2 $ 184.5 $ 105.9 $ — $ 142.8 $ 433.2 The following presents, for each of the fair value hierarchy levels, SPS’ proportionate allocation of the total postretirement benefit plan assets that were measured at fair value: Dec. 31, 2018 (a) Dec. 31, 2017 (a) (Millions of Dollars) Level 1 Level 2 Level 3 Measured at NAV Total Level 1 Level 2 Level 3 Measured at NAV Total Cash equivalents $ 1.8 $ — $ — $ — $ 1.8 $ 2.8 $ — $ — $ — $ 2.8 Insurance contracts — 4.3 — — 4.3 — 4.7 — — 4.7 Commingled funds: 12.8 — — 3.8 16.6 14.1 — — — 14.1 Debt securities: — 17.2 — — 17.2 — 19.0 — — 19.0 Equity securities: — — — — — 3.3 — — — 3.3 Other — 0.1 — — 0.1 — 0.2 — — 0.2 Total $ 14.6 $ 21.6 $ — $ 3.8 $ 40.0 $ 20.2 $ 23.9 $ — $ — $ 44.1 (a) See Note 8 for further information on fair value measurement inputs and methods. No assets transferred in or out of Level 3 for the years ended Dec. 31, 2018 or 2017 . Funded Status — Comparisons of the actuarially computed benefit obligation, changes in plan assets and funded status of the pension and postretirement health care plans for Xcel Energy are presented in the following table: Pension Benefits Postretirement Benefits (Millions of Dollars) 2018 2017 2018 2017 Change in Benefit Obligation: Obligation at Jan. 1 $ 515.9 $ 483.6 $ 47.0 $ 41.9 Service cost 9.7 9.8 1.1 0.9 Interest cost 18.4 19.7 1.6 1.7 Plan amendments — (1.0 ) — — Actuarial (gain) loss (34.8 ) 31.2 (5.1 ) 4.7 Plan participants’ contributions — — 0.6 0.6 Benefit payments (a) (31.4 ) (27.4 ) (3.4 ) (2.8 ) Obligation at Dec. 31 $ 477.8 $ 515.9 $ 41.8 $ 47.0 Change in Fair Value of Plan Assets: Fair value of plan assets at Jan. 1 $ 433.2 $ 380.4 $ 44.1 $ 42.3 Actual return on plan assets (17.6 ) 56.7 (1.3 ) 3.8 Employer contributions 8.0 23.5 — 0.2 Plan participants’ contributions — — 0.6 0.6 Benefit payments (31.4 ) (27.4 ) (3.4 ) (2.8 ) Fair value of plan assets at Dec. 31 $ 392.2 $ 433.2 $ 40.0 $ 44.1 Funded status of plans at Dec. 31 $ (85.6 ) $ (82.7 ) $ (1.8 ) $ (2.9 ) Amounts recognized in the Balance Sheet at Dec. 31: Noncurrent liabilities (85.6 ) (82.7 ) (1.8 ) (2.9 ) Net amounts recognized $ (85.6 ) $ (82.7 ) $ (1.8 ) $ (2.9 ) Significant Assumptions Used to Measure Benefit Obligations: Discount rate for year-end valuation 4.31 % 3.63 % 4.32 % 3.62 % Expected average long-term increase in compensation level 3.75 3.75 N/A N/A Mortality table RP-2014 RP-2014 RP-2014 RP-2014 Health care costs trend rate — initial: Pre-65 N/A N/A 6.50 % 7.00 % Health care costs trend rate — initial: Post-65 N/A N/A 5.30 % 5.50 % Ultimate trend assumption — initial: Pre-65 N/A N/A 4.50 % 4.50 % Ultimate trend assumption — initial: Post-65 N/A N/A 4.50 % 4.50 % Years until ultimate trend is reached N/A N/A 4 5 (a) Includes approximately $6.9 million in 2018 and $0 million in 2017, of lump-sum benefit payments used in the determination of a settlement charge. Accumulated benefit obligation for the pension plan was $445.8 million and $478.8 million as of Dec. 31, 2018 and 2017, respectively. Net Periodic Benefit Cost (Credit) — Net periodic benefit cost (credit) other than service cost component is included in other income in the statement of income. Components of net periodic benefit cost (credit) and the amounts recognized in other comprehensive income and regulatory assets and liabilities are as follows: Pension Benefits Postretirement Benefits (Millions of Dollars) 2018 2017 2016 2018 2017 2016 Service cost $ 9.7 $ 9.8 $ 9.8 $ 1.1 $ 0.9 $ 0.8 Interest cost 18.4 19.7 21.2 1.6 1.7 1.8 Expected return on plan assets (28.3 ) (27.9 ) (27.6 ) (2.5 ) (2.4 ) (2.4 ) Amortization of prior service credit (0.1 ) — — (0.4 ) (0.4 ) (0.4 ) Amortization of net loss 14.1 13.0 12.0 (0.4 ) (0.6 ) (0.6 ) Settlement charge (a) 3.2 — — — — — Net periodic pension cost (credit) 17.0 14.6 15.4 (0.6 ) (0.8 ) (0.8 ) Costs not recognized due to effects of regulation (2.2 ) 0.3 2.0 — — — Net benefit cost (credit) recognized for financial reporting $ 14.8 $ 14.9 $ 17.4 $ (0.6 ) $ (0.8 ) $ (0.8 ) Significant Assumptions Used to Measure Costs: Discount rate 3.63 % 4.13 % 4.66 % 3.62 % 4.13 % 4.65 % Expected average long-term increase in compensation level 3.75 3.75 4.00 — — — Expected average long-term rate of return on assets 6.78 6.78 6.78 5.80 5.80 5.80 (a) A settlement charge is required when the amount of all lump-sum distributions during the year is greater than the sum of the service and interest cost components of the annual net periodic pension cost. In 2018, as a result of lump-sum distributions during the 2018 plan year, SPS recorded a total pension settlement charge of $3.3 million the majority of which $0 million was not recognized due to the effects of regulation. Pension Benefits Postretirement Benefits (Millions of Dollars) 2018 2017 2018 2017 Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost: Net loss $ 230.9 $ 237.0 $ (9.6 ) $ (8.6 ) Prior service credit (1.2 ) (1.3 ) (1.8 ) (2.2 ) Total $ 229.7 $ 235.7 $ (11.4 ) $ (10.8 ) Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost Have Been Recorded as Follows Based Upon Expected Recovery in Rates: Current regulatory assets $ 12.9 $ 13.9 $ — $ — Noncurrent regulatory assets 216.8 221.8 — — Current regulatory liabilities — — (0.9 ) (0.8 ) Noncurrent regulatory liabilities — — (10.5 ) (10.0 ) Total $ 229.7 $ 235.7 $ (11.4 ) $ (10.8 ) Measurement date Dec. 31, 2018 Dec. 31, 2017 Dec. 31, 2018 Dec. 31, 2017 Cash Flows — Cash funding requirements can be impacted by changes to actuarial assumptions, actual asset levels and other calculations prescribed by the funding requirements of income tax and other pension-related regulations. Required contributions were made in 2016 - 2019 to meet minimum funding requirements. Total voluntary and required pension funding contributions across all four of Xcel Energy’s pension plans were as follows: • $150 million in January 2019, of which $17 million was attributable to SPS; • $150 million in 2018, of which $8 million was attributable to SPS; • $162 million in 2017, of which $24 million was attributable to SPS; and, • $125 million in 2016, of which $18 million was attributable to SPS. For future years, Xcel Energy and SPS anticipate contributions will be made as necessary. The postretirement health care plans have no funding requirements under income tax and other retirement-related regulations other than fulfilling benefit payment obligations, when claims are presented and approved. Additional cash funding requirements are prescribed by certain state and federal rate regulatory authorities. Xcel Energy’s voluntary postretirement funding contributions were as follows: • Expects to contribute approximately $11 million during 2019; • $11 million during 2018; • $20 million during 2017; and, • $18 million during 2016. • Amounts attributable to SPS were immaterial. Target asset allocations: Pension Benefits Postretirement Benefits 2018 2017 2018 2017 Domestic and international equity securities 35 % 34 % 18 % 24 % Long-duration fixed income securities 32 31 — — Short-to-intermediate fixed income securities 16 19 70 60 Alternative investments 15 14 8 9 Cash 2 2 4 7 Total 100 % 100 % 100 % 100 % Plan Amendments — Xcel Energy, which includes SPS, amended the Xcel Energy Inc. Nonbargaining Pension Plan (South) in 2017 to reduce supplemental benefits for non-bargaining participants as well as to allow the transfer of a portion of non-qualified pension obligations into the qualified plans. In 2018, there were no plan amendments made which affected the benefit obligation. Projected Benefit Payments SPS’ projected benefit payments: (Millions of Dollars) Projected Gross Projected Expected Net Projected 2019 29.7 3.2 — 3.2 2020 30.0 3.1 — 3.1 2021 29.3 3.2 — 3.2 2022 30.8 3.2 — 3.2 2023 30.8 3.2 — 3.2 2024-2028 156.2 14.4 0.2 14.2 Defined Contribution Plans Xcel Energy, which includes SPS, maintains 401(k) and other defined contribution plans that cover most employees. The expense to these plans for SPS was approximately $3 million in 2018 , 2017 and 2016 . |
Commitments and Contingencies
Commitments and Contingencies | 12 Months Ended |
Dec. 31, 2018 | |
Commitments and Contingencies Disclosure [Abstract] | |
Commitments and Contingencies | Commitments and Contingencies Legal SPS is involved in various litigation matters that are being defended and handled in the ordinary course of business. The assessment of whether a loss is probable or is a reasonable possibility, and whether the loss or a range of loss is estimable, often involves complex judgments about future events. Management maintains accruals for losses that are probable of being incurred and subject to reasonable estimation. Management is sometimes unable to estimate an amount or range of a reasonably possible loss in certain situations, including when (1) the damages sought are indeterminate, (2) the proceedings are in the early stages or (3) the matters involve novel or unsettled legal theories. In such cases, there is considerable uncertainty regarding the timing or ultimate resolution of such matters, including a possible eventual loss. 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 SPS’ financial statements. Unless otherwise required by GAAP, legal fees are expensed as incurred. Rate Matters SPP OATT Upgrade Costs — Under the SPP OATT, costs of transmission upgrades may be recovered from other SPP customers whose transmission service depends on capacity enabled by the upgrade. The SPP OATT has allowed SPP to charge for these upgrades since 2008, but SPP had not been charging its customers for these upgrades. In 2016, the FERC granted SPP’s request to recover the charges not billed since 2008. SPP subsequently billed SPS approximately $13 million for these charges. In July 2018, SPS’ appeal to the D.C. Circuit over the FERC rulings granting SPP the right to recover these charges was remanded to the FERC. SPS’ recovery of these charges (from 2008 through 2016) is being reviewed by the FERC, which is expected to rule in the first quarter of 2019. In October 2017, SPS filed a complaint against SPP regarding the amounts billed asserting that SPP has assessed upgrade charges to SPS in violation of the SPP OATT. The FERC has granted a rehearing of further consideration in May 2018. The timing of the FERC action on the SPS rehearing is uncertain. If SPS’ complaint results in additional charges or refunds, SPS will seek to recover or refund the differential in future rate proceedings. SPP Filing to Assign GridLiance Facilities to SPS Rate Zone — In August 2018, SPP filed a request with the FERC to amend its OATT to include the costs of the GridLiance High Plains, LLC. facilities in the SPS rate zone. In a previous filing, the FERC determined that some of these facilities did not qualify as transmission facilities under the SPP OATT. SPP’s proposed tariff changes could result in an increase in the ATRR of $9.5 million per year, with $6 million allocated to SPS’ retail customers. The remaining $3.5 million would be paid by other wholesale loads in the SPS rate zone. In September 2018, SPS protested the proposed SPP tariff charges, and asked the FERC to reject the SPP filing. On October 31, 2018, the FERC issued an order accepting the proposed charges as of November 1, 2018. In December 2018, the FERC hosted a settlement hearing over the matter. A hearing will be ordered if a settlement is not reached. SPS Filing to Modify Wholesale Transmission Rates - In 2018, SPS filed revisions to its wholesale transmission formula rate. The proposal includes an update to the depreciation rates for transmission plant. The new formula rate would provide flow-back of “excess” ADIT resulting from the TCJA and recover certain wholesale regulatory commission expenses. The proposed changes would increase wholesale transmission revenues by approximately $9.4 million , with approximately $4.4 million of the total being recovered in SPP regional transmission rates. SPS proposed that the formula rate changes be effective February 1, 2019. In January 2019, the FERC issued an order accepting the proposed rate changes as of February 1, 2019, subject to refund and settlement procedures. The first settlement conference is expected in the first quarter of 2019. Environmental New and changing federal and state environmental mandates can create financial liabilities for SPS, which are normally recovered through the regulated rate process. Site Remediation — Various federal and state environmental laws impose liability where hazardous substances or other regulated materials have been released to the environment. SPS may sometimes pay all or a portion of the cost to remediate sites where past activities of its predecessors or other parties have caused environmental contamination. Environmental contingencies could arise from various situations, including sites of former MGPs; and third-party sites, such as landfills, for which SPS is alleged to have sent wastes to that site. MGP, Landfill or Disposal Sites — SPS is currently investigating or remediating one MGP, landfill or other disposal site across its service territories, and these activities will continue through at least 2019. SPS accrued $0.1 million as of Dec. 31, 2018 and 2017, respectively, for this site. There may be insurance recovery and/or recovery from other potentially responsible parties, offsetting some portion of costs incurred. Environmental Requirements — Water and Waste Federal CWA WOTUS Rule — In 2015, the EPA and Corps published a final rule that significantly broadened the scope of waters under the CWA that are subject to federal jurisdiction, referred to as “WOTUS”. The Rule has been subject to significant litigation and is currently stayed in a portion of the country. SPS cannot estimate potential impacts until the legal and administrative processes are finalized, but expects costs will be recoverable through regulatory mechanisms. Federal CWA ELG — In 2015, the EPA issued a final ELG rule for power plants that discharge treated effluent to surface waters as well as utility-owned landfills that receive CCRs. In 2017, the EPA delayed the compliance date for flue gas desulfurization wastewater and bottom ash transport until November 2020. After 2020, SPS estimates that ELG compliance will be immaterial. The EPA, however, is conducting a rulemaking process to potentially revise the effluent limitations and pretreatment standards, which may impact compliance costs. SPS estimates these costs will be fully recoverable through regulatory mechanisms. Environmental Requirements — Air Regional Haze Rules — The regional haze program requires SO 2 , NO X and PM emission controls at power plants to reduce visibility impairment in national parks and wilderness areas. The program includes BART and reasonable further progress. Texas’ first regional haze plan has undergone federal review as described below. BART Determination for Texas: The EPA has issued a revised final rule adopting a BART alternative Texas only SO 2 trading program that applies to all Harrington and Tolk units. Under the trading program, SPS expects the allowance allocations to be sufficient for SO 2 emissions. The anticipated costs of compliance are not expected to have a material impact; and SPS believes that compliance costs would be recoverable through regulatory mechanisms. Several parties have challenged whether the final rule issued by the EPA should be considered to have met the requirements imposed in a Consent Decree entered by the United States District Court for the District of Columbia that established deadlines for the EPA to take final action on state regional haze plan submissions. The court has required status reports from the parties while the EPA works on the reconsideration rulemaking. In December 2017, the National Parks Conservation Association, Sierra Club, and Environmental Defense Fund appealed the EPA’s 2017 final BART rule to the Fifth Circuit, and filed a petition for administrative reconsideration. In January 2018, the court granted SPS’ motion to intervene in the Fifth Circuit litigation in support of the EPA’s final rule. The court has held the litigation in abeyance while the EPA decided whether to reconsider the rule. In August 2018, the EPA started a reconsideration rulemaking. It is not known when the EPA will make a final decision on this proposal. Reasonable Progress Rule: In January 2016, the EPA adopted a final rule establishing a federal implementation plan for reasonable further progress under the regional haze program for the state of Texas. The rule imposes SO 2 emission limitations that would require the installation of dry scrubbers on Tolk Units 1 and 2, with compliance required by February 2021. Investment costs associated with dry scrubbers could be $600 million . SPS appealed the EPA’s decision and obtained a stay of the final rule. In March 2017, the Fifth Circuit remanded the rule to the EPA for reconsideration, leaving the stay in effect. In a future rulemaking, the EPA will address whether SO 2 emission reductions beyond those required in the BART alternative rule are needed at Tolk under the “reasonable progress” requirements. The EPA has not announced a schedule for acting on the remanded rule. Implementation of the NAAQS for SO 2 — The EPA has designated all areas near SPS’ generating plants as attaining the SO 2 NAAQS with an exception. The EPA issued final designations which found the area near the Harrington plant as “unclassifiable.” The area near the Harrington plant is to be monitored for three years and a final designation is expected to be made by December 2020. If the area near the Harrington plant is designated nonattainment in 2020, the TCEQ will need to develop an implementation plan, designed to achieve the NAAQS by 2025. The TCEQ could require additional SO 2 controls at Harrington as part of such a plan. SPS cannot evaluate the impacts until the final designation is made and any required state plans are developed. SPS believes that should SO 2 control systems be required for a plant, compliance costs or the costs of alternative cost-effective generation will be recoverable through regulatory mechanisms and therefore does not expect a material impact on results of operations, financial position or cash flows. AROs — AROs have been recorded for SPS’ assets. SPS’ AROs were as follows: Dec. 31, 2018 (Millions of Dollars) Balance Jan. 1, 2018 Accretion Cash Flow Revisions (a) Balance Dec. 31, 2018 (b) Electric Steam production $ 20.3 $ 1.2 $ 0.5 $ 22.0 Distribution 7.0 0.3 1.8 9.1 Other 1.2 0.1 — 1.3 Total liability $ 28.5 $ 1.6 $ 2.3 $ 32.4 (a) In 2018, AROs were revised for changes in timing and estimates of cash flows. Changes in electric distribution AROs were primarily related to increased labor costs. (b) There were no ARO amounts incurred or settled in 2018. Dec. 31, 2017 (Millions of Dollars) Balance Jan. 1, 2017 Accretion Cash Flow Revisions (a) Balance Dec. 31, 2017 (b) Electric plant Steam production $ 20.7 $ 1.3 $ (1.7 ) $ 20.3 Distribution 6.8 0.2 — 7.0 Other 1.2 — — 1.2 Total liability $ 28.7 $ 1.5 $ (1.7 ) $ 28.5 (a) In 2017, an asbestos ARO was revised for changes in timing of estimated cash flows. (b) There were no ARO amounts incurred or settled in 2018. Indeterminate AROs — Outside of the recorded asbestos AROs, other plants or buildings may contain asbestos due to the age of many of SPS’ facilities, but no confirmation or measurement of the cost of removal could be determined as of Dec. 31, 2018. Therefore, an ARO has not been recorded for these facilities. Removal Costs — SPS records a regulatory liability for the plant removal costs that are recovered currently in rates. Generally, the accrual of future non-ARO removal obligations is not required. However, long-standing ratemaking practices approved by applicable state and federal regulatory commissions have allowed provisions for such costs in historical depreciation rates. These removal costs have accumulated based on varying rates as authorized by the appropriate regulatory entities. SPS has estimated the amount of removal costs accumulated through historic depreciation expense based on current factors used in the existing depreciation rates. Removal costs as of Dec. 31, 2018 and 2017 were $188 million and $197 million respectively. Leases — SPS leases a variety of equipment and facilities. These leases, primarily for office space, generating facilities, vehicles, aircraft and power-operated equipment, are accounted for as operating leases. Total expenses (including capacity payments) under operating lease obligations for SPS and the corresponding capacity payments for PPAs accounted for as operating leases for the year ended Dec. 31: (Millions of Dollars) 2018 2017 2016 Total expense $ 59.0 $ 57.8 $ 56.6 Capacity payments 51.1 51.4 50.6 Included in the future commitments under operating leases are estimated future capacity payments under PPAs that have been accounted for as operating leases. Future commitments under operating leases are: (Millions of Dollars) Operating PPA (a) (b) Operating Leases Total 2019 $ 5.2 $ 46.7 $ 51.9 2020 5.2 46.2 51.4 2021 5.1 46.2 51.3 2022 5.1 46.2 51.3 2023 5.1 46.2 51.3 Thereafter 56.3 450.8 507.1 (a) Amounts do not include PPAs accounted for as executory contracts. (b) PPA operating leases contractually expire through 2033 . Non-Lease PPAs — SPS has entered into PPAs with other utilities and energy suppliers with expiration dates through 2033 for purchased power to meet system load and energy requirements and meet operating reserve obligations. In general, these agreements provide for energy payments, based on actual energy delivered and capacity payments. Capacity payments are contingent on the IPP meeting contract obligations, including plant availability requirements. Certain contractual payments are adjusted based on market indices. The effects of price adjustments on our financial results are mitigated through purchased energy cost recovery mechanisms. Included in electric fuel and purchased power expenses for PPAs accounted for as executory contracts, were payments for capacity of $57.6 million , $58.4 million and $56.8 million in 2018 , 2017 and 2016 , respectively. At Dec. 31, 2018 , the estimated future payments for capacity that SPS is obligated to purchase pursuant to these executory contracts, subject to availability, were as follows: (Millions of Dollars) Capacity 2019 $ 20.3 2020 12.0 2021 12.2 2022 12.4 2023 12.6 Thereafter 5.7 Total $ 75.2 Fuel Contracts — SPS has entered into various long-term commitments for the purchase and delivery of a significant portion of its coal and natural gas requirements. These contracts expire between 2019 and 2033 . SPS is required to pay additional amounts depending on actual quantities shipped under these agreements. Estimated minimum purchases under these contracts as of Dec. 31, 2018 : (Millions of Dollars) Coal Natural gas Natural gas 2019 $ 127.3 $ 20.3 $ 30.3 2020 83.9 — 30.3 2021 41.0 — 25.2 2022 41.2 — 19.3 2023 — — 14.1 Thereafter — — 33.6 Total $ 293.4 $ 20.3 $ 152.8 VIEs — Under certain PPAs, SPS purchases power from IPPs for which SPS is required to reimburse fuel costs, or to participate in tolling arrangements under which SPS procures the natural gas required to produce the energy that it purchases. SPS has determined that certain IPPs are VIEs. SPS is not subject to risk of loss from the operations of these entities, and no significant financial support is required other than contractual payments for energy and capacity. In addition, certain solar PPAs provide an option to purchase emission allowances or sharing provisions related to production credits generated by the solar facility under contract. These specific PPAs create a variable interest in the IPP. SPS evaluated each of these VIEs for possible consolidation, including review of qualitative factors such as the length and terms of the contract, control over O&M, control over dispatch of electricity, historical and estimated future fuel and electricity prices, and financing activities. SPS concluded that these entities are not required to be consolidated in its financial statements because it does not have the power to direct the activities that most significantly impact the entities’ economic performance. SPS had approximately 1,197 MW and 897 MW of capacity under long-term PPAs at Dec. 31, 2018 and 2017 , respectively, with entities that have been determined to be VIEs. These agreements have expiration dates through 2041 . Fuel Contracts — SPS purchases all of its coal requirements for its Harrington and Tolk plant from TUCO under contracts that will expire in December 2022 . TUCO arranges for the purchase, receiving, transporting, unloading, handling, crushing, weighing, and delivery of coal to meet SPS’ requirements. TUCO is responsible for negotiating and administering contracts with coal suppliers, transporters and handlers. SPS has not provided any significant financial support to TUCO, other than contractual payments for delivered coal. However, the fuel contracts create a variable interest in TUCO due to SPS’ reimbursement of fuel procurement costs. SPS has determined that TUCO is a VIE. SPS has concluded that it is not the primary beneficiary of TUCO because SPS does not have the power to direct the activities that most significantly impact TUCO’s economic performance. |
Other Comprehensive Income
Other Comprehensive Income | 12 Months Ended |
Dec. 31, 2018 | |
Stockholders' Equity Note [Abstract] | |
Other Comprehensive Income | Other Comprehensive Income Changes in accumulated other comprehensive loss, net of tax, for the year ended Dec. 31: 2018 (Millions of Dollars) Gains and Losses on Cash Flow Hedges Defined Benefit Pension and Postretirement Items Total Accumulated other comprehensive loss at Jan. 1 $ (0.8 ) $ (0.7 ) $ (1.5 ) Losses reclassified from net accumulated other comprehensive loss: Interest rate derivatives (net of taxes of $0 and $0, respectively) 0.1 (a) — 0.1 Amortization of net actuarial loss (net of taxes of $0 and $0, respectively) — — (b) — Net current period other comprehensive income 0.1 — 0.1 Accumulated other comprehensive loss at Dec. 31 $ (0.7 ) $ (0.7 ) $ (1.4 ) 2017 (Millions of Dollars) Gains and Losses on Cash Flow Hedges Defined Benefit Pension and Postretirement Items Total Accumulated other comprehensive loss at Jan. 1 $ (0.7 ) $ (0.6 ) $ (1.3 ) Losses reclassified from net accumulated other comprehensive loss: Interest rate derivatives (net of taxes of $0.1 and $0, respectively) — (a) — — Amortization of net actuarial loss (net of taxes of $0 and $0, respectively) — 0.1 (b) 0.1 Net current period other comprehensive income (loss) — 0.1 0.1 Adoption of ASU No. 2018-02 (c) (0.1 ) (0.2 ) (0.3 ) Accumulated other comprehensive loss at Dec. 31 $ (0.8 ) $ (0.7 ) $ (1.5 ) (a) Included in interest charges. (b) Included in the computation of net periodic pension and postretirement benefit costs. See Note 9 for further information. (c) In 2017, SPS implemented ASU No. 2018-02 related to the TCJA, which resulted in reclassification of certain credit balances within accumulated other comprehensive loss to retained earnings. |
Related Party Transactions
Related Party Transactions | 12 Months Ended |
Dec. 31, 2018 | |
Related Party Transactions [Abstract] | |
Related Party Transactions | Related Party Transactions Xcel Energy Services Inc. provides management, administrative and other services for the subsidiaries of Xcel Energy Inc., including SPS. The services are provided and billed to each subsidiary in accordance with service agreements executed by each subsidiary. SPS uses the service provided by Xcel Energy Services Inc. whenever possible. Costs are charged directly to the subsidiary and are allocated if they cannot be directly assigned. Xcel Energy Inc., NSP-Minnesota, PSCo and SPS have established a utility money pool arrangement with the utility subsidiaries. See Note 5 for further information. Significant affiliate transactions among the companies and related parties for the years ended Dec. 31: (Millions of Dollars) 2018 2017 2016 Operating expenses: Purchased power $ — $ 1.4 $ 8.8 Other operating expenses — paid to Xcel Energy Services Inc. 195.1 196.6 188.2 Interest expense 0.6 — 0.2 Accounts receivable and payable with affiliates at Dec. 31 were: 2018 2017 (Millions of Dollars) Accounts Accounts Accounts Accounts NSP-Minnesota $ 4.7 $ — $ 1.0 $ — PSCo — 0.7 — 0.3 Other subsidiaries of Xcel Energy Inc. 5.8 19.2 0.3 22.3 $ 10.5 $ 19.9 $ 1.3 $ 22.6 |
Summarized Quarterly Financial
Summarized Quarterly Financial Data (Unaudited) | 12 Months Ended |
Dec. 31, 2018 | |
Quarterly Financial Information Disclosure [Abstract] | |
Summarized Quarterly Financial Data (Unaudited) | Summarized Quarterly Financial Data (Unaudited) Quarter Ended (Millions of Dollars) March 31, 2018 June 30, 2018 Sept. 30, 2018 Dec. 31, 2018 Operating revenues $ 447.2 $ 481.3 $ 540.1 $ 464.6 Operating income 57.1 87.6 111.0 56.0 Net income 33.1 58.5 81.5 40.2 Quarter Ended (Millions of Dollars) March 31, 2017 June 30, 2017 Sept. 30, 2017 Dec. 31, 2017 Operating revenues $ 460.1 $ 479.8 $ 551.6 $ 426.5 Operating income (a) 59.2 75.2 123.1 43.4 Net income 25.1 35.3 67.8 31.0 (a) In 2018, SPS implemented ASU No. 2017-07 related to net periodic benefit cost, which resulted in retrospective reclassification of pension costs from O&M expense to other income. |
Schedule II, Valuation and Qual
Schedule II, Valuation and Qualifying Accounts | 12 Months Ended |
Dec. 31, 2018 | |
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract] | |
Schedule II, Valuation and Qualifying Accounts | SOUTHWESTERN PUBLIC SERVICE CO. VALUATION AND QUALIFYING ACCOUNTS YEARS ENDED DEC. 31, 2018, 2017 AND 2016 Allowance for bad debts (Millions of Dollars) 2018 2017 2016 Balance at Jan. 1 $ 6.4 $ 6.4 $ 5.9 Additions Charged to Costs and Expenses 4.9 5.1 6.1 Additions Charged to Other Accounts (a) 1.0 1.2 0.9 Deductions from Reserves (b) (6.7 ) (6.3 ) (6.5 ) Balance at Dec. 31 $ 5.6 $ 6.4 $ 6.4 (a) Recovery of amounts previously written off. (b) Deductions relate primarily to bad debt write-offs. |
Summary of Significant Accoun_2
Summary of Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2018 | |
Accounting Policies [Abstract] | |
Business and System of Accounts | General — SPS is engaged in the regulated generation, purchase, transmission, distribution and sale of electricity. SPS’ financial statements and disclosures are presented in accordance with GAAP. All of SPS’ underlying accounting records also conform to the FERC uniform system of accounts or to systems required by various state regulatory commissions. |
Subsequent Events | SPS has evaluated the impact of events occurring after Dec. 31, 2018 up to the date of issuance of these financial statements. These statements contain all necessary adjustments and disclosures resulting from that evaluation. |
Use of Estimates | Use of Estimates — SPS uses estimates based on the best information available in recording transactions and balances resulting from business operations. Estimates are used on items such as plant depreciable lives or potential disallowances, AROs, certain regulatory assets and liabilities, tax provisions, uncollectible amounts, environmental costs, unbilled revenues, jurisdictional fuel and energy cost allocations and actuarially determined benefit costs. Recorded estimates are revised when better information becomes available or when actual amounts can be determined. Those revisions can affect operating results. |
Regulatory Accounting | Regulatory Accounting — SPS accounts for income and expense items in accordance with accounting guidance for regulated operations. Under this guidance: • Certain costs, which would otherwise be charged to expense or other comprehensive income, are deferred as regulatory assets based on the expected ability to recover the costs in future rates; and • Certain credits, which would otherwise be reflected as income or other comprehensive income, are deferred as regulatory liabilities based on the expectation the amounts will be returned to customers in future rates, or because the amounts were collected in rates prior to the costs being incurred. Estimates of recovering deferred costs and returning deferred credits are based on specific ratemaking decisions or precedent for each item. Regulatory assets and liabilities are amortized consistent with the treatment in the rate setting process. If changes in the regulatory environment occur, SPS may no longer be eligible to apply this accounting treatment, and may be required to eliminate regulatory assets and liabilities from its balance sheet. Such changes could have a material effect on SPS’ results of operations, financial condition or cash flows. See Note 4 for further information. |
Income Taxes | Income Taxes — SPS accounts for income taxes using the asset and liability method, which requires deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. SPS defers income taxes for all temporary differences between pretax financial and taxable income, and between the book and tax bases of assets and liabilities. SPS uses the tax rates that are scheduled to be in effect when the temporary differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in the period that includes the enactment date. The effects of SPS’ tax rate changes are generally subject to a normalization method of accounting. Therefore, the revaluation of most its net deferred taxes upon a tax rate reduction results in the establishment of a net regulatory liability which will be refundable to utility customers over the remaining life of the related assets. A tax rate increase would result in the establishment of a similar regulatory asset. Tax credits are recorded when earned unless there is a requirement to defer the benefit and amortize it over the book depreciable lives of the related property. The requirement to defer and amortize tax credits only applies to federal ITCs related to public utility property. Utility rate regulation also has resulted in the recognition of regulatory assets and liabilities related to income taxes. Deferred tax assets are reduced by a valuation allowance if it is more likely than not that some portion or all of the deferred tax asset will not be realized. SPS follows the applicable accounting guidance to measure and disclose uncertain tax positions that it has taken or expects to take in its income tax returns. SPS recognizes a tax position in its financial statements when it is more likely than not that the position will be sustained upon examination based on the technical merits of the position. Recognition of changes in uncertain tax positions are reflected as a component of income tax. SPS reports interest and penalties related to income taxes within the other income and interest charges in the statements of income. Xcel Energy Inc. and its subsidiaries, including SPS, files consolidated federal income tax returns as well as consolidated or separate state income tax returns. Federal income taxes paid by Xcel Energy Inc. are allocated to its subsidiaries based on separate company computations. A similar allocation is made for state income taxes paid by Xcel Energy Inc. in connection with consolidated state filings. Xcel Energy Inc. also allocates its own income tax benefits to its direct subsidiaries. See Notes 4 and 7 for further information. |
Property, Plant and Equipment and Depreciation | Property, Plant and Equipment and Depreciation — Property, plant and equipment is stated at original cost. The cost of plant includes direct labor and materials, contracted work, overhead costs and AFUDC. The cost of plant retired is charged to accumulated depreciation and amortization. Amounts recovered in rates for future removal costs are recorded as regulatory liabilities. Significant additions or improvements extending asset lives are capitalized, while repairs and maintenance costs are charged to expense as incurred. Maintenance and replacement of items determined to be less than a unit of property are charged to operating expenses as incurred. Planned maintenance activities are charged to operating expense unless the cost represents the acquisition of an additional unit of property or the replacement of an existing unit of property. Property, plant and equipment is tested for impairment when it is determined that the carrying value of the assets may not be recoverable. A loss is recognized in the current period if it becomes probable that part of a cost of a plant under construction or recently completed plant will be disallowed for recovery from customers and a reasonable estimate of the disallowance can be made. For investments in property, plant and equipment that are abandoned and not expected to go into service, incurred costs and related deferred tax amounts are compared to the discounted estimated future rate recovery, and a loss is recognized, if necessary. SPS records depreciation expense using the straight-line method over the plant’s useful life. Actuarial life studies are performed and submitted to the state and federal commissions for review. Upon acceptance by the various commissions, the resulting lives and net salvage rates are used to calculate depreciation. Depreciation expense, expressed as a percentage of average depreciable property, was 2.9% in 2018, 2.8% in 2017, and 2.7% in 2016. See Note 3 for further information. |
Asset Retirement Obligations | AROs — SPS accounts for AROs under accounting guidance that requires a liability for the fair value of an ARO to be recognized in the period in which it is incurred if it can be reasonably estimated, with the offsetting associated asset retirement costs capitalized as a long-lived asset. The liability is generally increased over time by applying the effective interest method of accretion, and the capitalized costs are depreciated over the useful life of the long-lived asset. Changes resulting from revisions to the timing or amount of expected asset retirement cash flows are recognized as an increase or a decrease in the ARO. SPS also recovers through rates certain future plant removal costs in addition to AROs. The accumulated removal costs for these obligations are reflected in the balance sheets as a regulatory liability. See Note 10 for further information. |
Benefit Plans and Other Postretirement Benefits | Benefit Plans and Other Postretirement Benefits — SPS maintains pension and postretirement benefit plans for eligible employees. Recognizing the cost of providing benefits and measuring the projected benefit obligation of these plans requires management to make various assumptions and estimates. Certain unrecognized actuarial gains and losses and unrecognized prior service costs or credits are deferred as regulatory assets and liabilities, rather than recorded as other comprehensive income, based on regulatory recovery mechanisms. See Note 9 for further information. |
Environmental Costs | Environmental Costs — Environmental costs are recorded when it is probable SPS is liable for remediation costs and the liability can be reasonably estimated. Costs are deferred as a regulatory asset if it is probable that the costs will be recovered from customers in future rates. Otherwise, the costs are expensed. If an environmental expense is related to facilities currently in use, such as emission-control equipment, the cost is capitalized and depreciated over the life of the plant. Estimated remediation costs are regularly adjusted as estimates are revised and remediation proceeds. If other participating PRPs exist and acknowledge their potential involvement with a site, costs are estimated and recorded only for SPS’ expected share of the cost. Future costs of restoring sites are treated as a capitalized cost of plant retirement. The depreciation expense levels recoverable in rates include a provision for removal expenses. Removal costs recovered in rates before the related costs are incurred are classified as a regulatory liability. See Note 10 for further information. |
Revenue From Contracts With Customers | Revenue From Contracts With Customers — Performance obligations related to the sale of energy are satisfied as energy is delivered to customers. SPS recognizes revenue that corresponds to the price of the energy delivered to the customer. The measurement of energy sales to customers is generally based on the reading of their meters, which occurs on a systematic basis throughout the month. At the end of each month, amounts of energy delivered to customers since the date of the last meter reading are estimated, and the corresponding unbilled revenue is recognized. SPS does not recognize a separate financing component of its collections from customers as contract terms are short-term in nature. SPS presents its revenues net of any excise or sales taxes or fees. SPS participates in SPP. SPS recognizes sales to both native load and other end use customers on a gross basis in electric revenues and cost of sales. Revenues and charges for short term wholesale sales of excess energy transacted through RTOs are also recorded on a gross basis. Other revenues and charges related to participating and transacting in RTOs are recorded on a net basis in cost of sales. See Note 6 for further information. |
Cash and Cash Equivalents | Cash and Cash Equivalents — SPS considers investments in instruments with a remaining maturity of three months or less at the time of purchase, to be cash equivalents. |
Accounts Receivable and Allowance for Bad Debts | Accounts Receivable and Allowance for Bad Debts — Accounts receivable are stated at the actual billed amount net of an allowance for bad debts. SPS establishes an allowance for uncollectible receivables based on a policy that reflects its expected exposure to the credit risk of customers. As of Dec. 31, 2018 and 2017, the allowance for bad debts was $5.6 million and $6.3 million , respectively. |
Inventory | Inventory — Inventory is recorded at average cost. As of Dec. 31, 2018, materials and supplies and fuel inventory were $25.7 million and $8.2 million , respectively. As of Dec. 31, 2017, materials and supplies and fuel inventory were $26.2 million and $14.2 million , respectively. |
Fair Value Measurements | Fair Value Measurements — SPS presents cash equivalents, interest rate derivatives and commodity derivatives at estimated fair values in its financial statements. Cash equivalents are recorded at cost plus accrued interest; money market funds are measured using quoted NAVs. For interest rate derivatives, quoted prices based primarily on observable market interest rate curves are used to establish fair value. For commodity derivatives, the most observable inputs available are generally used to determine the fair value of each contract. In the absence of a quoted price, SPS may use quoted prices for similar contracts or internally prepared valuation models to determine fair value. For the pension and postretirement plan assets published trading data and pricing models, generally using the most observable inputs available, are utilized to estimate fair value for each security. See Notes 8 and 9 for further information. |
Derivative Instruments | Derivative Instruments — SPS uses derivative instruments in connection with its utility commodity price and interest rate activities, including forward contracts, futures, swaps and options. Any derivative instruments qualifying for the normal purchases and normal sales exception are recorded on the balance sheets at fair value as derivative instruments. Classification of changes in fair value for those derivative instruments is dependent on the designation of a qualifying hedging relationship. Changes in fair value of derivative instruments not designated in a qualifying hedging relationship are reflected in current earnings or as a regulatory asset or liability. Classification as a regulatory asset or liability is based on expected recovery of derivative instrument settlements through fuel and purchased energy cost recovery mechanisms. Interest rate hedging transactions are recorded as a component of interest expense. Normal Purchases and Normal Sales — SPS enters into contracts for purchases and sales of commodities for use in its operations. At inception, contracts are evaluated to determine whether a derivative exists and/or whether an instrument may be exempted from derivative accounting if designated as a normal purchase or normal sale. See Note 8 for further information. |
AFUDC | AFUDC — AFUDC represents the cost of capital used to finance utility construction activity. AFUDC is computed by applying a composite financing rate to qualified CWIP. The amount of AFUDC capitalized as a utility construction cost is credited to other nonoperating income (for equity capital) and interest charges (for debt capital). AFUDC amounts capitalized are included in SPS’ rate base for establishing utility rates. |
Alternative Revenue Programs | Alternative Revenue — Certain rate rider mechanisms (including DSM programs) qualify as alternative revenue programs under GAAP. These mechanisms arise from costs imposed upon the utility by action of a regulator or legislative body related to an environmental, public safety or other mandate. When certain criteria are met, such as collection within 24 months , revenue is recognized equal to the revenue requirement, which may include incentives and return on rate base items. Billing amounts are revised periodically for differences between the total amount collected and the revenue earned, which may increase or decrease the level of revenue collected from customers. Alternative revenues arising from these programs are presented on a gross basis and disclosed separately from revenue from contracts with customers in the period earned. See Note 6 for further information. Conservation Programs — SPS has implemented programs in its jurisdictions to assist customers in conserving energy and reducing peak demand on the electric system. These programs include commercial motor, air conditioner and lighting upgrades, as well as residential rebates for participation in air conditioner interruption and home weatherization. The costs incurred for some DSM programs are deferred as permitted by the applicable regulatory jurisdiction. For those programs, costs are deferred if it is probable future revenue will be provided to permit recovery of the incurred cost. Revenues recognized for incentive programs designed for recovery of lost margins and/or conservation performance incentives are limited to amounts expected to be collected within 24 months from the annual period in which they are earned. SPS recovers approved conservation program costs in base rate revenue or through a rider. |
Emission Allowances | Emission Allowances — Emission allowances are recorded at cost plus broker commission fees. The inventory accounting model is utilized for all emission allowances and sales of these allowances are included in electric revenues. |
Renewable Energy Credits | RECs — Cost of RECs that are utilized for compliance purposes is recorded as electric fuel and purchased power expense. SPS reduces recoverable fuel costs for the cost of RECs and records that cost as a regulatory asset when the amount is recoverable in future rates. Sales of RECs are recorded in electric revenues on a gross basis. The cost of these RECs and amounts credited to customers under margin-sharing mechanisms are recorded in electric fuel and purchased power expense. |
Segment Reporting, Policy [Policy Text Block] | Segment Information — SPS has only one reportable segment. SPS is a wholly owned subsidiary of Xcel Energy Inc. and operates in the regulated electric utility industry providing wholesale and retail electric service in the states of Texas and New Mexico. Operating results from the regulated electric utility segment serve as the primary basis for the chief operating decision maker to evaluate the performance of SPS. |
Property Plant and Equipment _2
Property Plant and Equipment Property Plant and Equipment (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Property, Plant and Equipment [Abstract] | |
Public Utility Property, Plant, and Equipment | Major classes of property, plant and equipment: (Millions of Dollars) Dec. 31, 2018 Dec. 31, 2017 Property, plant and equipment Electric plant $ 7,227.7 $ 6,765.3 CWIP 847.3 351.9 Total property, plant and equipment 8,075.0 7,117.2 Less accumulated depreciation (2,128.6 ) (2,021.6 ) $ 5,946.4 $ 5,095.6 |
Regulatory Assets and Liabili_2
Regulatory Assets and Liabilities (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Regulatory Assets and Liabilities Disclosure [Abstract] | |
Regulatory Assets | Components of regulatory assets: (Millions of Dollars) See Remaining Dec. 31, 2018 Dec. 31, 2017 Regulatory Assets Current Noncurrent Current Noncurrent Pension and retiree medical obligations 9 Various $ 12.6 $ 222.1 $ 12.7 $ 223.0 Excess deferred taxes - TCJA 7 Various — 55.9 — 44.7 Recoverable deferred taxes on AFUDC recorded in plant Plant lives — 27.9 — 23.9 Net AROs (a) 1, 10 Plant lives — 25.7 — 24.2 Losses on reacquired debt Term of related debt 0.8 21.9 0.8 22.7 Conservation programs (b) 1 One to two years 0.7 0.6 2.7 0.7 Other Various 11.9 12.1 15.3 23.7 Total regulatory assets $ 26.0 $ 366.2 $ 31.5 $ 362.9 (a) Includes amounts recorded for future recovery of AROs. (b) Includes costs for conservation programs, as well as incentives allowed in certain jurisdictions. |
Regulatory Liabilities | Components of regulatory liabilities: (Millions of Dollars) See Remaining Dec. 31, 2018 Dec. 31, 2017 Regulatory Liabilities Current Noncurrent Current Noncurrent Deferred income tax adjustments and TCJA refunds (a) 7 Various $ 2.2 $ 569.8 $ — $ 568.6 Plant removal costs 1, 10 Plant lives — 187.7 — 196.9 Revenue subject to refund One to two years 11.3 8.1 6.8 6.5 Gain from asset sales Various — 2.4 — 2.5 Deferred electric energy costs Less than one year 56.5 — 48.5 — Contract valuation adjustments (b) 1, 8 Less than one year 14.7 — 12.7 — Other Various 1.1 12.9 0.8 10.1 Total regulatory liabilities $ 85.8 $ 780.9 $ 68.8 $ 784.6 (a) Includes the revaluation of recoverable/regulated plant ADIT and revaluation impact of non-plant ADIT due to the TCJA. (b) Includes the fair value of certain long-term PPAs used to meet energy capacity requirements. |
Borrowings and Other Financin_2
Borrowings and Other Financing Instruments (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Debt Disclosure [Abstract] | |
Money Pool [Table Text Block] | Money pool borrowings for SPS were as follows: Three Months Ended Dec. 31, 2018 Year Ended Dec. 31 (Amounts in Millions, Except Interest Rates) 2018 2017 2016 Borrowing limit $ 100 $ 100 $ 100 $ 100 Amount outstanding at period end — — — — Average amount outstanding 14 29 13 28 Maximum amount outstanding 74 100 100 100 Weighted average interest rate, computed on a daily basis 2.13 % 1.96 % 1.12 % 0.67 % Weighted average interest rate at end of period N/A N/A N/A N/A |
Short-Term Borrowings | Commercial paper outstanding for SPS was as follows: Three Months Ended Dec. 31, 2018 Year Ended Dec. 31 (Amounts in Millions, Except Interest Rates) 2018 2017 2016 Borrowing limit $ 400 $ 400 $ 400 $ 400 Amount outstanding at period end 42 42 — 50 Average amount outstanding 20 30 69 43 Maximum amount outstanding 100 144 176 140 Weighted average interest rate, computed on a daily basis 2.45 % 2.27 % 1.13 % 0.67 % Weighted average interest rate at end of period 2.80 2.80 NA 0.95 |
Schedule Of Debt To Total Capitalization Ratio [Table Text Block] | Features of SPS’ credit facility: Debt-to-Total Capitalization Ratio (a) Amount Facility May Be Increased (millions) Additional Periods For Which a One-Year Extension May Be Requested (b) 2018 2017 46% 46% $50 2 (a) The SPS credit facility has a financial covenant requiring that the debt-to-total capitalization ratio be less than or equal to 65% . (b) All extension requests are subject to majority bank group approval. |
Credit Facilities | SPS had the following committed credit facilities available as of Dec. 31, 2018 . Credit Facility (a) Drawn (b) Available $400 $44 $356 (a) This credit facility matures in June 2021 . (b) Includes letters of credit and outstanding commercial paper. |
Schedule of Capitalization [Table Text Block] | Long term debt obligations for SPS as of Dec. 31: (Millions of Dollars) Maturity Range Interest Rate Range 2018 Interest Rate Range 2017 2018 2017 Mortgage bonds 2024 - 2048 3.30% - 4.50% 3.30% - 4.50% $ 1,800 $ 1,500 Unsecured senior notes 2033 - 2036 6.00% 6.00% - 8.75% 350 350 Unamortized discount (4 ) (2 ) Unamortized debt issuance cost (20 ) (18 ) Current maturities — — Total long term debt $ 2,126 $ 1,830 |
Schedule of Long-Term Debt Issuances [Table Text Block] | 2018 financings: Amount Financing Instrument Interest Rate Maturity Date $300 million First mortgage bonds 4.40 % Nov 15, 2048 2017 financings: Amount Financing Instrument Interest Rate Maturity Date $450 million First mortgage bonds 3.70 % Aug 15, 2047 |
Schedule of Long-term Debt Instruments [Table Text Block] | SPS has the following preferred stock: Preferred Stock Authorized (Shares) Par Value of Preferred Stock Preferred Stock Outstanding (Shares) 2018 and 2017 SPS 10,000,000 1.00 0 |
Dividend Payment Restrictions [Text Block] | Requirements and actuals as of Dec. 31, 2018: Equity to Total Capitalization Ratio - Required Range Equity to Total Capitalization Ratio - Actual (a) Low High 2018 45.0 % 55.0 % 54.4 % (a) SPS excludes short-term debt. Unrestricted Retained Earnings Total Capitalization Limit on Total Capitalization 2018 2018 2018 SPS (a) $ 605.7 million $ 4.7 billion N/A (a) SPS may not pay a dividend that would cause it to lose its investment grade bond rating. |
Revenues (Tables)
Revenues (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Revenue from Contract with Customer [Abstract] | |
Disaggregation of Revenue [Table Text Block] | SPS’ operating revenues (subsequent to adoption of the revised revenue guidance) consists of the following: (Millions of Dollars) Year Ended Dec. 31, 2018 Major product lines Revenue from contracts with customers: Residential $ 363.7 C&I 828.3 Other 44.7 Total retail 1,236.7 Wholesale 426.0 Transmission 231.1 Other 12.8 Total revenue from contracts with customers 1,906.6 Alternative revenue and other 26.6 Total revenues $ 1,933.2 |
Income Taxes (Tables)
Income Taxes (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Income Tax Disclosure [Abstract] | |
Interest Payable related to Unrecognized Tax Benefits | Interest payable related to unrecognized tax benefits: (Millions of Dollars) 2018 2017 2016 Receivable (payable) for interest related to unrecognized tax benefits at Jan. 1 $ 0.5 $ (0.9 ) $ — Interest income (expense) related to unrecognized tax benefits 0.2 1.4 (0.9 ) Receivable (payable) for interest related to unrecognized tax benefits at Dec. 31 $ 0.7 $ 0.5 $ (0.9 ) |
Summary of Statute of Limitations Applicable to Open Tax Years | SPS is a member of the Xcel Energy affiliated group that files a consolidated federal income tax return. Statute of limitations applicable to Xcel Energy’s consolidated federal income tax returns expire as follows: Tax Year(s) Expiration 2009 - 2014 October 2019 2015 September 2019 2016 September 2020 2017 September 2021 |
Reconciliation of Unrecognized Tax Benefits | Unrecognized tax benefits - permanent vs temporary: (Millions of Dollars) Dec. 31, 2018 Dec. 31, 2017 Unrecognized tax benefit — Permanent tax positions $ 3.0 $ 2.3 Unrecognized tax benefit — Temporary tax positions 1.5 2.0 Total unrecognized tax benefit $ 4.5 $ 4.3 Changes in unrecognized tax benefits: (Millions of Dollars) 2018 2017 2016 Balance at Jan. 1 $ 4.3 $ 28.7 $ 24.7 Additions based on tax positions related to the current year 0.6 0.9 1.4 Reductions based on tax positions related to the current year (0.1 ) (0.6 ) — Additions for tax positions of prior years 0.1 1.3 3.9 Reductions for tax positions of prior years (0.3 ) (19.9 ) (1.3 ) Settlements with taxing authorities (0.1 ) (6.1 ) — Balance at Dec. 31 $ 4.5 $ 4.3 $ 28.7 |
Tax Benefits Associated with NOL and Tax Credit Carryforwards | Unrecognized tax benefits were reduced by tax benefits associated with NOL and tax credit carryforwards: (Millions of Dollars) Dec. 31, 2018 Dec. 31, 2017 NOL and tax credit carryforwards $ (3.8 ) $ (5.9 ) |
NOL and Tax Credit Carryforwards | NOL amounts represent the tax loss that is carried forward and tax credits represent the deferred tax asset. NOL and tax credit carryforwards as of Dec. 31 were as follows: (Millions of Dollars) 2018 2017 Federal NOL carryforward $ — $ 115.0 Federal tax credit carryforwards 5.7 5.2 State NOL carryforwards 2.9 40.5 |
Schedule of Effective Income Tax Rate Reconciliation | Total income tax expense from operations differs from the amount computed by applying the statutory federal income tax rate to income before income tax expense. Effective income tax rate for years ended Dec. 31: 2018 2017 (a) 2016 (a) Federal statutory rate 21.0 % 35.0 % 35.0 % State income tax on pretax income, net of federal tax effect 2.3 % 2.0 % 2.2 % Increases (decreases) in tax from: Regulatory differences - ARAM (b) (4.2 ) — — Tax Reform — (3.5 ) — Adjustments attributable to tax returns (1.5 ) (0.4 ) (1.1 ) Regulatory differences - other utility plant items (1.3 ) (0.8 ) (1.0 ) Amortization of excess nonplant deferred taxes (1.2 ) — — Tax credits recognized, net of federal income tax expense (0.7 ) (0.7 ) (0.5 ) Regulatory differences - Deferral of ARAM (c) 0.7 — — Change in unrecognized tax benefits 0.1 (1.0 ) 0.8 Other, net 0.2 (0.5 ) (0.4 ) Effective income tax rate 15.4 % 30.1 % 35.0 % (a) Prior periods have been reclassified to conform to current year presentation. (b) ARAM is a method to flow back excess deferred taxes to customers. (c) ARAM has been deferred when regulatory treatment has not been established. As Xcel Energy received direction from its regulatory commissions regarding the return of excess deferred taxes to customers, the ARAM deferral was reversed. This resulted in a reduction to tax expense with a corresponding reduction to revenue. |
Schedule of Components of Income Tax Expense (Benefit) | Components of income tax expense for years ended Dec. 31: (Millions of Dollars) 2018 2017 2016 Current federal tax expense (benefit) $ 12.3 $ (20.9 ) $ (40.9 ) Current state tax expense (benefit) 2.3 (12.8 ) (2.9 ) Current change in unrecognized tax expense (benefit) 2.3 (24.3 ) 3.1 Deferred federal tax expense 20.5 89.9 116.4 Deferred state tax expense 3.6 14.5 7.8 Deferred change in unrecognized tax (benefit) expense (2.0 ) 22.1 (1.2 ) Deferred ITCs (0.1 ) (0.1 ) (0.2 ) Total income tax expense $ 38.9 $ 68.4 $ 82.1 Components of deferred income tax expense as of Dec. 31: (Millions of Dollars) 2018 2017 2016 Deferred tax expense (benefit) excluding items below $ 44.2 $ (414.2 ) $ 128.4 Amortization and adjustments to deferred income taxes on income tax regulatory assets and liabilities (22.0 ) 540.7 (5.4 ) Tax (expense) benefit allocated to other comprehensive income, net of adoption of ASU No. 2018-02, and other (0.1 ) — — Deferred tax expense $ 22.1 $ 126.5 $ 123.0 |
Schedule of Deferred Tax Assets and Liabilities | Components of the net deferred tax liability as of Dec. 31: (Millions of Dollars) 2018 2017 Deferred tax liabilities: Differences between book and tax bases of property $ 680.6 $ 654.4 Regulatory assets 49.2 46.8 Pension expense 32.3 33.8 Other 2.9 4.6 Total deferred tax liabilities $ 765.0 $ 739.6 Deferred tax assets: Regulatory liabilities 116.8 114.6 NOL carryforward 0.2 26.2 Deferred fuel costs 12.7 10.4 Other employee benefits 5.6 5.8 Tax credit carryforward 5.7 5.2 Other 4.9 2.5 Total deferred tax assets $ 145.9 $ 164.7 Net deferred tax liability $ 619.1 $ 574.9 |
Fair Value of Financial Asset_2
Fair Value of Financial Assets and Liabilities (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Fair Value Disclosures [Abstract] | |
Gross Notional Amounts of Commodity FTRs | Gross notional amounts of commodity FTRs at Dec. 31, 2018 and 2017: (Amounts in Millions) (a) Dec. 31, 2018 Dec. 31, 2017 MWh of electricity 5.5 4.3 (a) amounts are not reflective of net positions in the underlying commodities. |
Financial Impact of Qualifying Cash Flow Hedges on Accumulated Other Comprehensive Loss | Financial impact of qualifying interest rate cash flow hedges on SPS’ accumulated other comprehensive loss, included in the statements of common stockholder’s equity and in the statements of comprehensive income: (Millions of Dollars) 2018 2017 2016 Accumulated other comprehensive loss related to cash flow hedges at Jan. 1 $ (0.8 ) $ (0.7 ) $ (0.8 ) After-tax net realized losses on derivative transactions reclassified into earnings 0.1 — 0.1 Adoption of ASU. 2018-02 (a) — (0.1 ) — Accumulated other comprehensive loss related to cash flow hedges at Dec. 31 $ (0.7 ) $ (0.8 ) $ (0.7 ) (a) In 2017, SPS implemented ASU No. 2018-02 related to TCJA, which resulted in reclassification of certain credit balances within net accumulated other comprehensive loss to retained earnings. |
Derivative Assets and Liabilities Measured at Fair Value on a Recurring Basis by Hierarchy Level | The following table presents for each of the fair value hierarchy levels, SPS’ derivative assets and liabilities measured at fair value on a recurring basis at Dec. 31, 2018 and 2017: Dec. 31, 2018 Dec. 31, 2017 Fair Value Fair Value (Millions of Dollars) Level 1 Level 2 Level 3 Fair Value Total Netting (a) Total Level 1 Level 2 Level 3 Fair Value Total Netting (a) Total Current derivative assets Other derivative instruments: Electric commodity $ — $ — $ 14.9 $ 14.9 $ (0.2 ) $ 14.7 $ — $ — $ 14.7 $ 14.7 $ (2.0 ) $ 12.7 Total current derivative assets $ — $ — $ 14.9 $ 14.9 $ (0.2 ) 14.7 $ — $ — $ 14.7 $ 14.7 $ (2.0 ) 12.7 PPAs (b) 3.1 3.2 Current derivative instruments $ 17.8 $ 15.9 Noncurrent derivative assets PPAs (b) 15.8 19.0 Noncurrent derivative instruments $ 15.8 $ 19.0 Current derivative liabilities Other derivative instruments: Electric commodity $ — $ — $ 0.2 $ 0.2 $ (0.2 ) $ — $ — $ — $ 2.0 $ 2.0 $ (2.0 ) $ — Total current derivative liabilities $ — $ — $ 0.2 $ 0.2 $ (0.2 ) — $ — $ — $ 2.0 $ 2.0 $ (2.0 ) — PPAs (b) 3.6 3.6 Current derivative instruments $ 3.6 $ 3.6 Noncurrent derivative liabilities PPAs (b) 16.4 19.9 Noncurrent derivative instruments $ 16.4 $ 19.9 (a) SPS nets derivative instruments and related collateral in its balance sheet when supported by a legally enforceable master netting agreement, and all derivative instruments and related collateral amounts were subject to master netting agreements at Dec. 31, 2018 and 2017. At both Dec. 31, 2018 and 2017, derivative assets and liabilities include no obligations to return cash collateral or rights to reclaim cash collateral. The counterparty netting excludes settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements. (b) During 2006, SPS qualified these contracts under the normal purchase exception. Based on this qualification, the contracts are no longer adjusted to fair value and the previous carrying value of these contracts will be amortized over the remaining contract lives along with the offsetting regulatory assets and liabilities. |
Changes in Level 3 Commodity Derivatives | Changes in Level 3 commodity derivatives for the years ended Dec. 31, 2018, 2017 and 2016: Year Ended Dec. 31 (Millions of Dollars) 2018 2017 2016 Balance at Jan. 1 $ 12.7 $ 2.0 $ 5.1 Purchases 32.3 41.2 7.6 Settlements (41.6 ) (55.8 ) (41.9 ) Net transactions recorded during the period: Net gains recognized as regulatory assets 11.3 25.3 31.2 Balance at Dec. 31 $ 14.7 $ 12.7 $ 2.0 |
Carrying Amount and Fair Value of Long-term Debt | 2018 2017 (Millions of Dollars) Carrying Amount Fair Value Carrying Amount Fair Value Long-term debt, including current portion $ 2,126.1 $ 2,139.8 $ 1,829.9 $ 2,002.0 |
Benefit Plans and Other Postr_2
Benefit Plans and Other Postretirement Benefits (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Benefit Plans and Other Postretirement Benefits [Abstract] | |
Target Asset Allocations and Plan Assets Measured at Fair Value | The following presents, for each of the fair value hierarchy levels, SPS’ pension plan assets measured at fair value: Dec. 31, 2018 Dec. 31, 2017 (Millions of Dollars) Level 1 Level 2 Level 3 Measured at NAV Total Level 1 Level 2 Level 3 Measured at NAV Total Cash equivalents $ 21.6 $ — $ — $ — $ 21.6 26.9 — — — $ 26.9 Commingled funds: 128.6 — — 132.5 261.1 145.7 — — 142.7 288.4 Debt securities: — 98.1 — — 98.1 — 105.3 — — 105.3 Equity securities: 14.4 — — — 14.4 15.2 — — — 15.2 Other 0.2 0.8 — (4.0 ) (3.0 ) (3.3 ) 0.6 — 0.1 (2.6 ) Total $ 164.8 $ 98.9 $ — $ 128.5 $ 392.2 $ 184.5 $ 105.9 $ — $ 142.8 $ 433.2 The following presents, for each of the fair value hierarchy levels, SPS’ proportionate allocation of the total postretirement benefit plan assets that were measured at fair value: Dec. 31, 2018 (a) Dec. 31, 2017 (a) (Millions of Dollars) Level 1 Level 2 Level 3 Measured at NAV Total Level 1 Level 2 Level 3 Measured at NAV Total Cash equivalents $ 1.8 $ — $ — $ — $ 1.8 $ 2.8 $ — $ — $ — $ 2.8 Insurance contracts — 4.3 — — 4.3 — 4.7 — — 4.7 Commingled funds: 12.8 — — 3.8 16.6 14.1 — — — 14.1 Debt securities: — 17.2 — — 17.2 — 19.0 — — 19.0 Equity securities: — — — — — 3.3 — — — 3.3 Other — 0.1 — — 0.1 — 0.2 — — 0.2 Total $ 14.6 $ 21.6 $ — $ 3.8 $ 40.0 $ 20.2 $ 23.9 $ — $ — $ 44.1 (a) See Note 8 for further information on fair value measurement inputs and methods. Target asset allocations: Pension Benefits Postretirement Benefits 2018 2017 2018 2017 Domestic and international equity securities 35 % 34 % 18 % 24 % Long-duration fixed income securities 32 31 — — Short-to-intermediate fixed income securities 16 19 70 60 Alternative investments 15 14 8 9 Cash 2 2 4 7 Total 100 % 100 % 100 % 100 % |
Funded Status of Plans | Funded Status — Comparisons of the actuarially computed benefit obligation, changes in plan assets and funded status of the pension and postretirement health care plans for Xcel Energy are presented in the following table: Pension Benefits Postretirement Benefits (Millions of Dollars) 2018 2017 2018 2017 Change in Benefit Obligation: Obligation at Jan. 1 $ 515.9 $ 483.6 $ 47.0 $ 41.9 Service cost 9.7 9.8 1.1 0.9 Interest cost 18.4 19.7 1.6 1.7 Plan amendments — (1.0 ) — — Actuarial (gain) loss (34.8 ) 31.2 (5.1 ) 4.7 Plan participants’ contributions — — 0.6 0.6 Benefit payments (a) (31.4 ) (27.4 ) (3.4 ) (2.8 ) Obligation at Dec. 31 $ 477.8 $ 515.9 $ 41.8 $ 47.0 Change in Fair Value of Plan Assets: Fair value of plan assets at Jan. 1 $ 433.2 $ 380.4 $ 44.1 $ 42.3 Actual return on plan assets (17.6 ) 56.7 (1.3 ) 3.8 Employer contributions 8.0 23.5 — 0.2 Plan participants’ contributions — — 0.6 0.6 Benefit payments (31.4 ) (27.4 ) (3.4 ) (2.8 ) Fair value of plan assets at Dec. 31 $ 392.2 $ 433.2 $ 40.0 $ 44.1 Funded status of plans at Dec. 31 $ (85.6 ) $ (82.7 ) $ (1.8 ) $ (2.9 ) Amounts recognized in the Balance Sheet at Dec. 31: Noncurrent liabilities (85.6 ) (82.7 ) (1.8 ) (2.9 ) Net amounts recognized $ (85.6 ) $ (82.7 ) $ (1.8 ) $ (2.9 ) Significant Assumptions Used to Measure Benefit Obligations: Discount rate for year-end valuation 4.31 % 3.63 % 4.32 % 3.62 % Expected average long-term increase in compensation level 3.75 3.75 N/A N/A Mortality table RP-2014 RP-2014 RP-2014 RP-2014 Health care costs trend rate — initial: Pre-65 N/A N/A 6.50 % 7.00 % Health care costs trend rate — initial: Post-65 N/A N/A 5.30 % 5.50 % Ultimate trend assumption — initial: Pre-65 N/A N/A 4.50 % 4.50 % Ultimate trend assumption — initial: Post-65 N/A N/A 4.50 % 4.50 % Years until ultimate trend is reached N/A N/A 4 5 (a) Includes approximately $6.9 million in 2018 and $0 million in 2017, of lump-sum benefit payments used in the determination of a settlement charge. Accumulated benefit obligation for the pension plan was $445.8 million and $478.8 million as of Dec. 31, 2018 and 2017, respectively. |
Components of Net Periodic Benefit Costs | Components of net periodic benefit cost (credit) and the amounts recognized in other comprehensive income and regulatory assets and liabilities are as follows: Pension Benefits Postretirement Benefits (Millions of Dollars) 2018 2017 2016 2018 2017 2016 Service cost $ 9.7 $ 9.8 $ 9.8 $ 1.1 $ 0.9 $ 0.8 Interest cost 18.4 19.7 21.2 1.6 1.7 1.8 Expected return on plan assets (28.3 ) (27.9 ) (27.6 ) (2.5 ) (2.4 ) (2.4 ) Amortization of prior service credit (0.1 ) — — (0.4 ) (0.4 ) (0.4 ) Amortization of net loss 14.1 13.0 12.0 (0.4 ) (0.6 ) (0.6 ) Settlement charge (a) 3.2 — — — — — Net periodic pension cost (credit) 17.0 14.6 15.4 (0.6 ) (0.8 ) (0.8 ) Costs not recognized due to effects of regulation (2.2 ) 0.3 2.0 — — — Net benefit cost (credit) recognized for financial reporting $ 14.8 $ 14.9 $ 17.4 $ (0.6 ) $ (0.8 ) $ (0.8 ) Significant Assumptions Used to Measure Costs: Discount rate 3.63 % 4.13 % 4.66 % 3.62 % 4.13 % 4.65 % Expected average long-term increase in compensation level 3.75 3.75 4.00 — — — Expected average long-term rate of return on assets 6.78 6.78 6.78 5.80 5.80 5.80 (a) A settlement charge is required when the amount of all lump-sum distributions during the year is greater than the sum of the service and interest cost components of the annual net periodic pension cost. In 2018, as a result of lump-sum distributions during the 2018 plan year, SPS recorded a total pension settlement charge of $3.3 million the majority of which $0 million was not recognized due to the effects of regulation. |
Projected Benefit Payments for the Pension and Postretirement Benefit Plans | Projected Benefit Payments SPS’ projected benefit payments: (Millions of Dollars) Projected Gross Projected Expected Net Projected 2019 29.7 3.2 — 3.2 2020 30.0 3.1 — 3.1 2021 29.3 3.2 — 3.2 2022 30.8 3.2 — 3.2 2023 30.8 3.2 — 3.2 2024-2028 156.2 14.4 0.2 14.2 |
Other Postretirement Benefits Plan [Member] | |
Benefit Plans and Other Postretirement Benefits [Abstract] | |
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost | Pension Benefits Postretirement Benefits (Millions of Dollars) 2018 2017 2018 2017 Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost: Net loss $ 230.9 $ 237.0 $ (9.6 ) $ (8.6 ) Prior service credit (1.2 ) (1.3 ) (1.8 ) (2.2 ) Total $ 229.7 $ 235.7 $ (11.4 ) $ (10.8 ) Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost Have Been Recorded as Follows Based Upon Expected Recovery in Rates: Current regulatory assets $ 12.9 $ 13.9 $ — $ — Noncurrent regulatory assets 216.8 221.8 — — Current regulatory liabilities — — (0.9 ) (0.8 ) Noncurrent regulatory liabilities — — (10.5 ) (10.0 ) Total $ 229.7 $ 235.7 $ (11.4 ) $ (10.8 ) Measurement date Dec. 31, 2018 Dec. 31, 2017 Dec. 31, 2018 Dec. 31, 2017 |
Commitments and Contingencies (
Commitments and Contingencies (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Commitments and Contingencies Disclosure [Abstract] | |
Total expense for energy and capacity payments table text block [Table Text Block] | Total expenses (including capacity payments) under operating lease obligations for SPS and the corresponding capacity payments for PPAs accounted for as operating leases for the year ended Dec. 31: (Millions of Dollars) 2018 2017 2016 Total expense $ 59.0 $ 57.8 $ 56.6 Capacity payments 51.1 51.4 50.6 |
Estimated Minimum Purchases Under Fuel Contracts | Estimated minimum purchases under these contracts as of Dec. 31, 2018 : (Millions of Dollars) Coal Natural gas Natural gas 2019 $ 127.3 $ 20.3 $ 30.3 2020 83.9 — 30.3 2021 41.0 — 25.2 2022 41.2 — 19.3 2023 — — 14.1 Thereafter — — 33.6 Total $ 293.4 $ 20.3 $ 152.8 |
Estimated Future Payments for Capacity and Energy Pursuant to Purchased Power Agreements | At Dec. 31, 2018 , the estimated future payments for capacity that SPS is obligated to purchase pursuant to these executory contracts, subject to availability, were as follows: (Millions of Dollars) Capacity 2019 $ 20.3 2020 12.0 2021 12.2 2022 12.4 2023 12.6 Thereafter 5.7 Total $ 75.2 |
Future Commitments Under Operating Leases | Future commitments under operating leases are: (Millions of Dollars) Operating PPA (a) (b) Operating Leases Total 2019 $ 5.2 $ 46.7 $ 51.9 2020 5.2 46.2 51.4 2021 5.1 46.2 51.3 2022 5.1 46.2 51.3 2023 5.1 46.2 51.3 Thereafter 56.3 450.8 507.1 (a) Amounts do not include PPAs accounted for as executory contracts. (b) PPA operating leases contractually expire through 2033 . |
Asset Retirement Obligations | SPS’ AROs were as follows: Dec. 31, 2018 (Millions of Dollars) Balance Jan. 1, 2018 Accretion Cash Flow Revisions (a) Balance Dec. 31, 2018 (b) Electric Steam production $ 20.3 $ 1.2 $ 0.5 $ 22.0 Distribution 7.0 0.3 1.8 9.1 Other 1.2 0.1 — 1.3 Total liability $ 28.5 $ 1.6 $ 2.3 $ 32.4 (a) In 2018, AROs were revised for changes in timing and estimates of cash flows. Changes in electric distribution AROs were primarily related to increased labor costs. (b) There were no ARO amounts incurred or settled in 2018. Dec. 31, 2017 (Millions of Dollars) Balance Jan. 1, 2017 Accretion Cash Flow Revisions (a) Balance Dec. 31, 2017 (b) Electric plant Steam production $ 20.7 $ 1.3 $ (1.7 ) $ 20.3 Distribution 6.8 0.2 — 7.0 Other 1.2 — — 1.2 Total liability $ 28.7 $ 1.5 $ (1.7 ) $ 28.5 (a) In 2017, an asbestos ARO was revised for changes in timing of estimated cash flows. (b) There were no ARO amounts incurred or settled in 2018. |
Other Comprehensive Income (Tab
Other Comprehensive Income (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Stockholders' Equity Note [Abstract] | |
Changes in Accumulated Other Comprehensive Income (Loss), Net of Tax | Changes in accumulated other comprehensive loss, net of tax, for the year ended Dec. 31: 2018 (Millions of Dollars) Gains and Losses on Cash Flow Hedges Defined Benefit Pension and Postretirement Items Total Accumulated other comprehensive loss at Jan. 1 $ (0.8 ) $ (0.7 ) $ (1.5 ) Losses reclassified from net accumulated other comprehensive loss: Interest rate derivatives (net of taxes of $0 and $0, respectively) 0.1 (a) — 0.1 Amortization of net actuarial loss (net of taxes of $0 and $0, respectively) — — (b) — Net current period other comprehensive income 0.1 — 0.1 Accumulated other comprehensive loss at Dec. 31 $ (0.7 ) $ (0.7 ) $ (1.4 ) 2017 (Millions of Dollars) Gains and Losses on Cash Flow Hedges Defined Benefit Pension and Postretirement Items Total Accumulated other comprehensive loss at Jan. 1 $ (0.7 ) $ (0.6 ) $ (1.3 ) Losses reclassified from net accumulated other comprehensive loss: Interest rate derivatives (net of taxes of $0.1 and $0, respectively) — (a) — — Amortization of net actuarial loss (net of taxes of $0 and $0, respectively) — 0.1 (b) 0.1 Net current period other comprehensive income (loss) — 0.1 0.1 Adoption of ASU No. 2018-02 (c) (0.1 ) (0.2 ) (0.3 ) Accumulated other comprehensive loss at Dec. 31 $ (0.8 ) $ (0.7 ) $ (1.5 ) |
Related Party Transactions (Tab
Related Party Transactions (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Related Party Transactions [Abstract] | |
Related Party Transactions | Significant affiliate transactions among the companies and related parties for the years ended Dec. 31: (Millions of Dollars) 2018 2017 2016 Operating expenses: Purchased power $ — $ 1.4 $ 8.8 Other operating expenses — paid to Xcel Energy Services Inc. 195.1 196.6 188.2 Interest expense 0.6 — 0.2 Accounts receivable and payable with affiliates at Dec. 31 were: 2018 2017 (Millions of Dollars) Accounts Accounts Accounts Accounts NSP-Minnesota $ 4.7 $ — $ 1.0 $ — PSCo — 0.7 — 0.3 Other subsidiaries of Xcel Energy Inc. 5.8 19.2 0.3 22.3 $ 10.5 $ 19.9 $ 1.3 $ 22.6 |
Summarized Quarterly Financia_2
Summarized Quarterly Financial Data (Unaudited) (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Quarterly Financial Information Disclosure [Abstract] | |
Summarized Quarterly Financial Data (Unaudited) | Quarter Ended (Millions of Dollars) March 31, 2018 June 30, 2018 Sept. 30, 2018 Dec. 31, 2018 Operating revenues $ 447.2 $ 481.3 $ 540.1 $ 464.6 Operating income 57.1 87.6 111.0 56.0 Net income 33.1 58.5 81.5 40.2 Quarter Ended (Millions of Dollars) March 31, 2017 June 30, 2017 Sept. 30, 2017 Dec. 31, 2017 Operating revenues $ 460.1 $ 479.8 $ 551.6 $ 426.5 Operating income (a) 59.2 75.2 123.1 43.4 Net income 25.1 35.3 67.8 31.0 (a) In 2018, SPS implemented ASU No. 2017-07 related to net periodic benefit cost, which resulted in retrospective reclassification of pension costs from O&M expense to other income. |
Summary of Significant Accoun_3
Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Property, Plant and Equipment [Abstract] | |||
Depreciation expense expressed as a percentage of average depreciable property | 2.90% | 2.80% | 2.70% |
Cash and Cash Equivalents [Abstract] | |||
Maximum number of months of remaining maturity at time of purchase to consider investments in certain instruments as cash equivalents | three months | ||
Accounts, Notes, Loans and Financing Receivable, Classified [Abstract] | |||
Allowance for Doubtful Accounts Receivable, Current | $ 5.6 | $ 6.3 | |
Alternative Revenue Programs [Abstract] | |||
Maximum number of months following end of annual period in which revenues are earned to be included in incentive programs | 24 months | ||
Public Utilities, Inventory [Line Items] | |||
Inventory | $ 33.9 | 40.4 | |
Supplies | |||
Public Utilities, Inventory [Line Items] | |||
Inventory | 25.7 | 26.2 | |
Fuel | |||
Public Utilities, Inventory [Line Items] | |||
Inventory | $ 8.2 | $ 14.2 |
Accounting Pronouncements Adopt
Accounting Pronouncements Adoption of New Accounting Pronouncements (Details) - USD ($) $ in Millions | 12 Months Ended | |
Dec. 31, 2017 | Dec. 31, 2016 | |
Other Expense | Accounting Standards Update 2017-07 | ||
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||
Net benefit cost recognized for financial reporting | $ 4.1 | $ 4 |
Property Plant and Equipment _3
Property Plant and Equipment Property Plant and Equipment (Details) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017 |
Property, Plant and Equipment [Line Items] | ||
Property, plant and equipment | $ 8,075 | $ 7,117.2 |
Property, plant and equipment, net | 5,946.4 | 5,095.6 |
Electric plant | ||
Property, Plant and Equipment [Line Items] | ||
Property, plant and equipment | 7,227.7 | 6,765.3 |
CWIP | ||
Property, Plant and Equipment [Line Items] | ||
Property, plant and equipment | 847.3 | 351.9 |
Nuclear Fuel [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment | $ 2,128.6 | $ 2,021.6 |
Regulatory Assets and Liabili_3
Regulatory Assets and Liabilities, Regulatory Assets (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | ||
Regulatory Assets [Line Items] | |||
Regulatory Asset, Current | $ 26,000 | $ 31,500 | |
Regulatory Asset, Noncurrent | 366,200 | 362,900 | |
Past expenditures not currently earning a return | 48,000 | 64,000 | |
Pension and Retiree Medical Obligations | |||
Regulatory Assets [Line Items] | |||
Regulatory Asset, Current | 12,600 | 12,700 | |
Regulatory Asset, Noncurrent | $ 222,100 | 223,000 | |
Regulatory asset, remaining amortization period | Various | ||
Excess deferred taxes - TCJA | |||
Regulatory Assets [Line Items] | |||
Regulatory Asset, Current | $ 0 | 0 | |
Regulatory Asset, Noncurrent | $ 55,900 | 44,700 | |
Regulatory asset, remaining amortization period | Various | ||
Recoverable Deferred Taxes on AFUDC Recorded in Plant | |||
Regulatory Assets [Line Items] | |||
Regulatory Asset, Current | $ 0 | 0 | |
Regulatory Asset, Noncurrent | $ 27,900 | 23,900 | |
Regulatory asset, remaining amortization period | Plant lives | ||
Net AROs | |||
Regulatory Assets [Line Items] | |||
Regulatory Asset, Current | [1] | $ 0 | 0 |
Regulatory Asset, Noncurrent | [1] | $ 25,700 | 24,200 |
Regulatory asset, remaining amortization period | Plant lives | ||
Losses on Reacquired Debt | |||
Regulatory Assets [Line Items] | |||
Regulatory Asset, Current | $ 800 | 800 | |
Regulatory Asset, Noncurrent | $ 21,900 | 22,700 | |
Regulatory asset, remaining amortization period | Term of related debt | ||
Conservation Programs | |||
Regulatory Assets [Line Items] | |||
Regulatory Asset, Current | [2] | $ 700 | 2,700 |
Regulatory Asset, Noncurrent | [2] | $ 600 | 700 |
Regulatory Asset Amortization Period, minimum | 1 year | ||
Regulatory Asset Amortization Period, maximum | 2 years | ||
Other Regulatory Assets | |||
Regulatory Assets [Line Items] | |||
Regulatory Asset, Current | $ 11,900 | 15,300 | |
Regulatory Asset, Noncurrent | $ 12,100 | $ 23,700 | |
Regulatory asset, remaining amortization period | Various | ||
[1] | Includes amounts recorded for future recovery of AROs. | ||
[2] | Includes costs for conservation programs, as well as incentives allowed in certain jurisdictions. |
Regulatory Assets and Liabili_4
Regulatory Assets and Liabilities, Regulatory Liabilities (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | ||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | $ 85.8 | $ 68.8 | |
Regulatory Liability, Noncurrent | 780.9 | 784.6 | |
Deferred Income Tax Adjustments and TCJA Refunds | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | [1] | 2.2 | 0 |
Regulatory Liability, Noncurrent | [1] | $ 569.8 | 568.6 |
Regulatory liability, remaining amortization period | Various | ||
Plant Removal Costs | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | $ 0 | 0 | |
Regulatory Liability, Noncurrent | $ 187.7 | 196.9 | |
Regulatory liability, remaining amortization period | Plant lives | ||
Revenue Subject to Refund | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | $ 11.3 | 6.8 | |
Regulatory Liability, Noncurrent | $ 8.1 | 6.5 | |
Regulatory liability, remaining amortization period, minimum | 1 year | ||
Regulatory liability, remaining amortization period, maximum | 2 years | ||
Gain From Asset Sales | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | $ 0 | 0 | |
Regulatory Liability, Noncurrent | $ 2.4 | 2.5 | |
Regulatory liability, remaining amortization period | Various | ||
Deferred Electric Energy Costs | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | $ 56.5 | 48.5 | |
Regulatory Liability, Noncurrent | $ 0 | 0 | |
Regulatory liability, remaining amortization period, maximum | 1 year | ||
Contract Valuation Adjustments | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | [2] | $ 14.7 | 12.7 |
Regulatory Liability, Noncurrent | [2] | $ 0 | 0 |
Regulatory liability, remaining amortization period, maximum | 1 year | ||
Other Regulatory Liabilities | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | $ 1.1 | 0.8 | |
Regulatory Liability, Noncurrent | $ 12.9 | $ 10.1 | |
Regulatory liability, remaining amortization period | Various | ||
[1] | Includes the revaluation of recoverable/regulated plant ADIT and revaluation impact of non-plant ADIT due to the TCJA. | ||
[2] | Includes costs for conservation programs, as well as incentives allowed in certain jurisdictions. |
Borrowings and Other Financin_3
Borrowings and Other Financing Instruments, Short-Term Borrowings (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Short-term Debt [Line Items] | ||||
Amount outstanding at period end | $ 42 | $ 42 | $ 0 | |
Money Pool | ||||
Short-term Debt [Line Items] | ||||
Borrowing limit | 100 | 100 | 100 | $ 100 |
Amount outstanding at period end | 0 | 0 | 0 | 0 |
Average amount outstanding | 14 | 29 | 13 | 28 |
Maximum amount outstanding | $ 74 | $ 100 | $ 100 | $ 100 |
Weighted average interest rate, computed on a daily basis (percentage) | 2.13% | 1.96% | 1.12% | 0.67% |
Commercial Paper | ||||
Short-term Debt [Line Items] | ||||
Borrowing limit | $ 400 | $ 400 | $ 400 | $ 400 |
Amount outstanding at period end | 42 | 42 | 0 | 50 |
Average amount outstanding | 20 | 30 | 69 | 43 |
Maximum amount outstanding | $ 100 | $ 144 | $ 176 | $ 140 |
Weighted average interest rate, computed on a daily basis (percentage) | 2.45% | 2.27% | 1.13% | 0.67% |
Weighted average interest rate at period end (percentage) | 2.80% | 2.80% | 0.95% |
Borrowings and Other Financin_4
Borrowings and Other Financing Instruments, Letters of Credit (Details) - USD ($) $ in Millions | 12 Months Ended | |
Dec. 31, 2018 | Dec. 31, 2017 | |
Line of Credit Facility [Line Items] | ||
Amount outstanding at period end | $ 42 | $ 0 |
Letter of Credit | ||
Line of Credit Facility [Line Items] | ||
Amount outstanding at period end | $ 2 | $ 3 |
Letter of Credit | Letter of Credit | ||
Line of Credit Facility [Line Items] | ||
Line of Credit Facility, Expiration Period | 1 year |
Borrowings and Other Financin_5
Borrowings and Other Financing Instruments, Credit Facility (Details) - Credit Facility | 12 Months Ended | |
Dec. 31, 2018USD ($) | Dec. 31, 2017USD ($) | |
Line of Credit Facility [Line Items] | ||
Line Of Credit Facility Debt To Total Capitalization Ratio | 46.00% | 46.00% |
Line Of Credit Facility Maximum Amount Credit Facility May Be Increased | $ 50,000,000 | |
Number Of Additional Periods Revolving Termination Date Can Be Extended Subject To Majority Bank Group Approval | 2 | |
Term Of Each Additional Period Revolving Termination Date Can Be Extended Subject To Majority Bank Group Approval | 1 | |
Line Of Credit Facility Maximum Debt To Total Capitalization Ratio Allowed | 65.00% | |
Line Of Credit Facility Minimum Threshhold Percentage Of Subsidiary Assets To Consolidated Assets Required To Initiate Cross Default Provisions | 15.00% | |
Line of Credit Facility, Minimum Amount of Indebtedness in Default to Initiate Cross Default Provisions | $ 75,000,000 | |
Credit facility | 400,000,000 | |
Drawn | 44,000,000 | |
Available | $ 356,000,000 | |
Debt Instrument, Maturity Date | Jun. 30, 2021 | |
Direct advances on the credit outstanding | $ 0 | $ 0 |
Borrowings and Other Financin_6
Borrowings and Other Financing Instruments, Long-Term Borrowings (Details) - USD ($) $ in Millions | 12 Months Ended | |
Dec. 31, 2018 | Dec. 31, 2017 | |
Debt Instrument [Line Items] | ||
Debt Instrument, Unamortized Discount (Premium), Net | $ (4) | $ (2) |
Unamortized Debt Issuance Expense | (20) | (18) |
Long-term Debt, Current Maturities | 0 | 0 |
Long-term Debt, Excluding Current Maturities | 2,126.1 | 1,829.9 |
Deferred Finance Costs, Noncurrent, Net | 20 | 18 |
First Mortgage Bonds, Series due: | ||
Debt Instrument [Line Items] | ||
Long-term Debt, Gross | $ 1,800 | $ 1,500 |
Debt Instrument, Maturity Date Range, End | Jan. 1, 2048 | |
Debt Instrument, Maturity Date Range, Start | Jun. 15, 2024 | |
First Mortgage Bonds, Series due: | Series Due June 15, 2048 [Member] | ||
Debt Instrument [Line Items] | ||
Interest Rate, Stated Percentage (in hundredths) | 4.40% | |
Face Amount | $ 300 | |
Debt Instrument, Maturity Date | Nov. 15, 2048 | |
First Mortgage Bonds, Series due: | Series Due August 15, 2047 | ||
Debt Instrument [Line Items] | ||
Interest Rate, Stated Percentage (in hundredths) | 3.70% | |
Face Amount | $ 450 | |
Debt Instrument, Maturity Date | Aug. 15, 2047 | |
Unsecured Debt [Member] | ||
Debt Instrument [Line Items] | ||
Long-term Debt, Gross | $ 350 | $ 350 |
Debt Instrument, Maturity Date Range, End | Oct. 1, 2036 | |
Debt Instrument, Maturity Date Range, Start | Oct. 1, 2033 | |
Combined Total | ||
Debt Instrument [Line Items] | ||
Long-term Debt, Excluding Current Maturities | $ 2,126 | $ 1,830 |
Maximum | First Mortgage Bonds, Series due: | ||
Debt Instrument [Line Items] | ||
Interest Rate, Stated Percentage (in hundredths) | 4.50% | 4.50% |
Maximum | Unsecured Debt [Member] | ||
Debt Instrument [Line Items] | ||
Interest Rate, Stated Percentage (in hundredths) | 6.00% | 8.75% |
Minimum | First Mortgage Bonds, Series due: | ||
Debt Instrument [Line Items] | ||
Interest Rate, Stated Percentage (in hundredths) | 3.30% | 3.30% |
Minimum | Unsecured Debt [Member] | ||
Debt Instrument [Line Items] | ||
Interest Rate, Stated Percentage (in hundredths) | 6.00% | 6.00% |
Credit Facility | ||
Debt Instrument [Line Items] | ||
Debt Instrument, Maturity Date | Jun. 30, 2021 |
Borrowings and Other Financin_7
Borrowings and Other Financing Instruments Borrowings and Other Financing Instruments, Preferred Stock (Details) | Dec. 31, 2018$ / sharesshares |
Preferred Stock [Abstract] | |
Preferred Stock, Shares Authorized | 10,000,000 |
Preferred Stock, Par or Stated Value Per Share | $ / shares | $ 1 |
Preferred Stock, Shares Outstanding | 0 |
Borrowings and Other Financin_8
Borrowings and Other Financing Instruments Borrowings and Other Financing Instruments, Dividend and Other Restrictions (Details) $ in Millions | Dec. 31, 2018USD ($) |
Dividend and Other Restrictions [Abstract] | |
Equity to total capitalization ratio (excluding short-term debt), low end of range | 45.00% |
Equity to total capitalization ratio (excluding short-term debt), high end of range | 55.00% |
Equity to total capitalization ratio (excluding short-term debt) | 54.40% |
Unrestricted Retained Earnings Per State Regulatory Commissions Dividend Restrictions | $ 605.7 |
Capitalization, Short term debt, long term debt and equity | $ 4,700 |
Revenues (Details)
Revenues (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended | |||||||||
Dec. 31, 2017 | Sep. 30, 2017 | Jun. 30, 2017 | Mar. 31, 2017 | Dec. 31, 2016 | Sep. 30, 2016 | Jun. 30, 2016 | Mar. 31, 2016 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Disaggregation of Revenue [Line Items] | |||||||||||
Revenues | $ 464.6 | $ 540.1 | $ 481.3 | $ 447.2 | $ 426.5 | $ 551.6 | $ 479.8 | $ 460.1 | $ 1,933.2 | $ 1,918 | $ 1,851 |
Regulated Electric [Member] | Retail | |||||||||||
Disaggregation of Revenue [Line Items] | |||||||||||
Revenue from Contract with Customer, Including Assessed Tax | 1,236.7 | ||||||||||
Regulated Electric [Member] | Retail | Residential | |||||||||||
Disaggregation of Revenue [Line Items] | |||||||||||
Revenue from Contract with Customer, Including Assessed Tax | 363.7 | ||||||||||
Regulated Electric [Member] | Retail | Commercial and industrial (C&I) | |||||||||||
Disaggregation of Revenue [Line Items] | |||||||||||
Revenue from Contract with Customer, Including Assessed Tax | 828.3 | ||||||||||
Regulated Electric [Member] | Retail | Other | |||||||||||
Disaggregation of Revenue [Line Items] | |||||||||||
Revenue from Contract with Customer, Including Assessed Tax | 44.7 | ||||||||||
Regulated Electric [Member] | Wholesale | |||||||||||
Disaggregation of Revenue [Line Items] | |||||||||||
Revenue from Contract with Customer, Including Assessed Tax | 426 | ||||||||||
Regulated Electric [Member] | Transmission | |||||||||||
Disaggregation of Revenue [Line Items] | |||||||||||
Revenue from Contract with Customer, Including Assessed Tax | 231.1 | ||||||||||
Regulated Electric [Member] | Other | |||||||||||
Disaggregation of Revenue [Line Items] | |||||||||||
Revenue from Contract with Customer, Including Assessed Tax | 12.8 | ||||||||||
Regulated Electric [Member] | Product [Member] | |||||||||||
Disaggregation of Revenue [Line Items] | |||||||||||
Revenue from Contract with Customer, Including Assessed Tax | 1,906.6 | ||||||||||
Regulated Electric [Member] | Alternative and Other [Member] | |||||||||||
Disaggregation of Revenue [Line Items] | |||||||||||
Revenues | 26.6 | ||||||||||
Operating Segments [Member] | Regulated Electric [Member] | |||||||||||
Disaggregation of Revenue [Line Items] | |||||||||||
Revenues | $ 1,933.2 |
Income Taxes (Details)
Income Taxes (Details) - USD ($) | 1 Months Ended | 3 Months Ended | 12 Months Ended | ||||||||||||
Dec. 31, 2017 | Dec. 31, 2018 | Sep. 30, 2017 | Sep. 30, 2015 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2012 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | ||||
Federal Tax Reform [Abstract] | |||||||||||||||
Tax Cuts and Jobs Act of 2017, Corporate Federal Tax Rate | 21.00% | 21.00% | |||||||||||||
Tax Cuts and Jobs Act of 2017, Net Operating Loss Deduction Limitation, Percent of Taxable income | 80.00% | ||||||||||||||
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Regulatory Liability, Provisional Income Tax (Expense) Benefit, Gross | $ 559,000,000 | ||||||||||||||
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Provisional Income Tax Expense (Benefit) | 8,000,000 | ||||||||||||||
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Net Income Reduction | 2,000,000 | ||||||||||||||
Tax Audits [Abstract] | |||||||||||||||
Unrecognized Tax Benefits, Interest on Income Taxes Accrued | $ (700,000) | $ (500,000) | $ (900,000) | $ 0 | |||||||||||
Interest Income (Expense) related to unrecognized tax benefits | $ (200,000) | (1,400,000) | $ 900,000 | ||||||||||||
Unrecognized Tax Benefits [Abstract] | |||||||||||||||
Unrecognized tax benefit — Permanent tax positions | 3,000,000 | 2,300,000 | |||||||||||||
Unrecognized tax benefit — Temporary tax positions | 1,500,000 | 2,000,000 | |||||||||||||
Total unrecognized tax benefit | $ 4,300,000 | $ 4,500,000 | 4,300,000 | 28,700,000 | 24,700,000 | 4,500,000 | 4,300,000 | 28,700,000 | $ 24,700,000 | ||||||
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] | |||||||||||||||
Balance at Jan. 1 | 4,300,000 | 28,700,000 | 24,700,000 | ||||||||||||
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions | 600,000 | 900,000 | 1,400,000 | ||||||||||||
Unrecognized Tax Benefits, Decrease Resulting from Current Period Tax Positions | (100,000) | (600,000) | 0 | ||||||||||||
Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions | 100,000 | 1,300,000 | 3,900,000 | ||||||||||||
Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions | (300,000) | (19,900,000) | (1,300,000) | ||||||||||||
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities | (100,000) | (6,100,000) | 0 | ||||||||||||
Balance at Dec. 31 | $ 4,300,000 | $ 4,500,000 | $ 4,500,000 | $ 4,300,000 | $ 28,700,000 | ||||||||||
Tax Benefits Associated With NOL And Tax Credit Carryforwards [Abstract] | |||||||||||||||
NOL and tax credit carryforwards | (3,800,000) | (5,900,000) | |||||||||||||
Net Deferred Tax Liability associated with the Unrecognized Tax Benefit Amounts and Related NOLs and Tax Credit Carryforwards | (800,000) | (2,700,000) | |||||||||||||
Decrease in Unrecognized Tax Benefits is Reasonably Possible | 3,600,000 | ||||||||||||||
Unrecognized Tax Benefits, Income Tax Penalties Accrued | 0 | 0 | $ 0 | ||||||||||||
Effective Income Tax Rate Reconciliation, Percent [Abstract] | |||||||||||||||
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent | 21.00% | 35.00% | [1] | 35.00% | [1] | ||||||||||
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent | 2.30% | 2.00% | [1] | 2.20% | [1] | ||||||||||
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent | [2] | (4.20%) | 0.00% | [1] | 0.00% | [1] | |||||||||
Effective Income Tax Rate Reconciliation,Other Reconciling Items, Percent | 0.00% | (3.50%) | [1] | 0.00% | [1] | ||||||||||
Effective Income Tax Reconciliation, Adjustments Attributable to Tax Returns, Percent | (1.50%) | (0.40%) | [1] | (1.10%) | [1] | ||||||||||
Effective Income Tax Rate Reconciliation, Other Regulatory Items, Percent | (1.30%) | (0.80%) | [1] | (1.00%) | [1] | ||||||||||
Amortization of excess nonplant deferred taxes | (1.20%) | (0.00%) | [1] | (0.00%) | [1] | ||||||||||
Effective Income Tax Rate Reconciliation Regulatory Differences Utility Plant Items | (0.70%) | (0.70%) | [1] | (0.50%) | [1] | ||||||||||
Effective Income Tax Rate Reconciliation, Tax Cuts and Jobs Act of 2017, Change in Tax Rate, Percent | [3] | 0.70% | 0.00% | [1] | 0.00% | [1] | |||||||||
Effective Income Tax Rate Reconciliation Change In Unrecognized Tax Benefits | 0.10% | (1.00%) | [1] | 0.80% | [1] | ||||||||||
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent | 0.20% | (0.50%) | [1] | (0.40%) | [1] | ||||||||||
Effective Income Tax Rate Reconciliation, Percent | 15.40% | 30.10% | [1] | 35.00% | [1] | ||||||||||
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract] | |||||||||||||||
Current Federal Tax Expense (Benefit) | $ 12,300,000 | $ (20,900,000) | $ (40,900,000) | ||||||||||||
Current State and Local Tax Expense (Benefit) | 2,300,000 | (12,800,000) | (2,900,000) | ||||||||||||
Current Change In Unrecognized Tax Expense (Benefit) | 2,300,000 | (24,300,000) | 3,100,000 | ||||||||||||
Deferred Federal Income Tax Expense (Benefit) | 20,500,000 | 89,900,000 | 116,400,000 | ||||||||||||
Deferred State and Local Income Tax Expense (Benefit) | 3,600,000 | 14,500,000 | 7,800,000 | ||||||||||||
Deferred Change In Unrecognized Tax Expense (Benefit) | (2,000,000) | 22,100,000 | (1,200,000) | ||||||||||||
Deferred investment tax credits | (100,000) | (100,000) | (200,000) | ||||||||||||
Income Tax Expense (Benefit) | 38,900,000 | 68,400,000 | 82,100,000 | ||||||||||||
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] | |||||||||||||||
Deferred tax expense (benefit) excluding selected items | 44,200,000 | (414,200,000) | 128,400,000 | ||||||||||||
Amortization and adjustments to deferred income taxes on income tax regulatory assets and liabilities | (22,000,000) | 540,700,000 | (5,400,000) | ||||||||||||
Other Comprehensive Income (Loss), Tax | (100,000) | 0 | 0 | ||||||||||||
Deferred Income Tax Expense (Benefit) | $ 22,100,000 | 126,500,000 | $ 123,000,000 | ||||||||||||
Deferred Tax Liabilities, Gross [Abstract] | |||||||||||||||
Deferred Tax Liabilities, Property, Plant and Equipment | 680,600,000 | 654,400,000 | |||||||||||||
Deferred Tax Liabilities, Regulatory Assets | 49,200,000 | 46,800,000 | |||||||||||||
Deferred Tax Liabilities, Compensation and Benefits, Employee Benefits | 32,300,000 | 33,800,000 | |||||||||||||
Deferred Tax Liabilities, Other | 2,900,000 | 4,600,000 | |||||||||||||
Deferred Tax Liabilities, Gross | 765,000,000 | 739,600,000 | |||||||||||||
Deferred Tax Assets, Gross [Abstract] | |||||||||||||||
Deferred Tax Assets Regulatory Liabilities | 116,800,000 | 114,600,000 | |||||||||||||
Deferred Tax Assets, Operating Loss Carryforwards | 200,000 | 26,200,000 | |||||||||||||
Deferred Tax Assets Unbilled Revenue Fuel Costs | 12,700,000 | 10,400,000 | |||||||||||||
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits | 5,600,000 | 5,800,000 | |||||||||||||
Deferred Tax Assets, Tax Credit Carryforwards | 5,700,000 | 5,200,000 | |||||||||||||
Deferred Tax Assets, Other | 4,900,000 | 2,500,000 | |||||||||||||
Deferred Tax Assets, Net of Valuation Allowance | 145,900,000 | 164,700,000 | |||||||||||||
Deferred Tax Liabilities, Net | 619,100,000 | 574,900,000 | |||||||||||||
Internal Revenue Service (IRS) | |||||||||||||||
Tax Audits [Abstract] | |||||||||||||||
Operating Loss Carryforwards | 0 | 115,000,000 | |||||||||||||
Tax Credit Carryforward, Amount | 5,700,000 | 5,200,000 | |||||||||||||
Carryforward expiration date range, low | 2,021 | ||||||||||||||
Carryforward expiration date range, high | 2,038 | ||||||||||||||
Tax years under examination, Concluded | 2012 and 2013 | ||||||||||||||
Year(s) under examination | 2014 - 2016 | 2012 and 2013 | 2010 and 2011 | ||||||||||||
Year of carryback claim under examination | 2,009 | ||||||||||||||
Potential Tax Adjustments | $ 0 | ||||||||||||||
TEXAS | |||||||||||||||
Tax Audits [Abstract] | |||||||||||||||
Earliest year subject to examination | 2,010 | ||||||||||||||
State and Local Jurisdiction | |||||||||||||||
Tax Audits [Abstract] | |||||||||||||||
Operating Loss Carryforwards | $ 2,900,000 | $ 40,500,000 | |||||||||||||
Carryforward expiration date range, low | 2,021 | ||||||||||||||
Carryforward expiration date range, high | 2,036 | ||||||||||||||
Plant Related Regulatory Liability [Member] | |||||||||||||||
Federal Tax Reform [Abstract] | |||||||||||||||
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Regulatory Liability, Provisional Income Tax (Expense) Benefit | 426,000,000 | ||||||||||||||
Non-Plant Related Regulated Liability [Member] | |||||||||||||||
Federal Tax Reform [Abstract] | |||||||||||||||
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Regulatory Liability, Provisional Income Tax (Expense) Benefit | 28,000,000 | ||||||||||||||
Non-Plant Related Regulatory Asset [Member] | |||||||||||||||
Federal Tax Reform [Abstract] | |||||||||||||||
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Regulatory Asset, Provisional Income Tax Expense (Benefit) | $ 45,000,000 | ||||||||||||||
[1] | Prior periods have been reclassified to conform to current year presentation. | ||||||||||||||
[2] | ARAM is a method to flow back excess deferred taxes to customers. | ||||||||||||||
[3] | ARAM has been deferred when regulatory treatment has not been established. As Xcel Energy received direction from its regulatory commissions regarding the return of excess deferred taxes to customers, the ARAM deferral was reversed. This resulted in a reduction to tax expense with a corresponding reduction to revenue. |
Fair Value of Financial Asset_3
Fair Value of Financial Assets and Liabilities, Derivative Instruments (Details) MWh in Millions, $ in Millions | Dec. 31, 2018USD ($)MWhCounterparty | Dec. 31, 2017MWh | |
Credit Concentration Risk | |||
Consideration of Credit Risk and Concentrations [Abstract] | |||
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure | 8 | ||
Credit Concentration Risk | Municipal or Cooperative Entities or Other Utilities [Member] | |||
Consideration of Credit Risk and Concentrations [Abstract] | |||
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure | 6 | ||
Credit Concentration Risk | External Credit Rating, Investment Grade [Member] | |||
Consideration of Credit Risk and Concentrations [Abstract] | |||
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure | 2 | ||
Wholesale, trading and non-trading commodity credit exposure for the most significant counterparties | $ | $ 11.6 | ||
Percentage of wholesale, trading and non-trading commodity credit exposure for the most significant counterparties (in hundredths) | 28.00% | ||
Credit Concentration Risk | No Investment Grade Ratings from External Credit Rating Agencies [Member] | |||
Consideration of Credit Risk and Concentrations [Abstract] | |||
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure | 5 | ||
Wholesale, trading and non-trading commodity credit exposure for the most significant counterparties | $ | $ 8.7 | ||
Percentage of wholesale, trading and non-trading commodity credit exposure for the most significant counterparties (in hundredths) | 21.00% | ||
Credit Concentration Risk | External Credit Rating, Non Investment Grade [Member] | |||
Consideration of Credit Risk and Concentrations [Abstract] | |||
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure | 1 | ||
Wholesale, trading and non-trading commodity credit exposure for the most significant counterparties | $ | $ 0.6 | ||
Percentage of wholesale, trading and non-trading commodity credit exposure for the most significant counterparties (in hundredths) | 1.00% | ||
Interest Rate Swap | |||
Interest Rate Derivatives [Abstract] | |||
Amount of accumulated other comprehensive gains (losses) related to interest rate derivatives expected to be reclassified into earnings within the next twelve months | $ | $ (0.1) | ||
Electric Commodity (in megawatt hours) | |||
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract] | |||
Derivative, Nonmonetary Notional Amount | MWh | [1] | 5.5 | 4.3 |
[1] | amounts are not reflective of net positions in the underlying commodities. |
Fair Value of Financial Asset_4
Fair Value of Financial Assets and Liabilities, Financial Impact of Qualifying Cash Flow Hedges (Details) - USD ($) $ in Thousands | 12 Months Ended | |||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | ||
Financial Impact of Qualifying Cash Flow Hedges on Accumulated Other Comprehensive Income (Loss) [Roll Forward] | ||||
Accumulated other comprehensive loss related to cash flow hedges at Jan. 1 | $ (800) | $ (700) | $ (800) | |
After-tax net realized losses on derivative transactions reclassified into earnings | (100) | 0 | (100) | |
Adoption of ASU. 2018-02 (a) | [1] | 0 | (100) | 0 |
Accumulated other comprehensive loss related to cash flow hedges at Dec. 31 | $ (700) | $ (800) | $ (700) | |
[1] | In 2017, SPS implemented ASU No. 2018-02 related to TCJA, which resulted in reclassification of certain credit balances within net accumulated other comprehensive loss to retained earnings. |
Fair Value of Financial Asset_5
Fair Value of Financial Assets and Liabilities, Impact of Derivative Activity (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Financial Impact of Qualifying Fair Value Hedges on Earnings [Abstract] | |||
Derivative instruments designated as fair value hedges | $ 0 | $ 0 | $ 0 |
Designated as Hedging Instrument | Cash Flow Hedges | Interest Rate | |||
Impact of Derivative Activity on Accumulated Other Comprehensive Loss, Regulatory Assets and Liabilities, and Income [Abstract] | |||
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net | (0.1) | (0.1) | (0.2) |
Other Derivative Instruments | Electric Commodity | |||
Impact of Derivative Activity on Accumulated Other Comprehensive Loss, Regulatory Assets and Liabilities, and Income [Abstract] | |||
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities | 7 | 0.5 | 3 |
Pre-tax (gains) losses reclassified into income during the period from regulatory assets and (liabilities) | $ (4.4) | $ (0.8) | $ (2.1) |
Fair Value of Financial Asset_6
Fair Value of Financial Assets and Liabilities, Derivative Assets and Liabilities at Fair Value (Details) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017 | |
Derivatives, Fair Value [Line Items] | |||
Derivative Asset, Collateral, Obligation to Return Cash, Offset | $ 0 | $ 0 | |
Other Current Assets | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Asset, Fair Value, Gross Asset | 17.8 | 15.9 | |
Other Noncurrent Assets | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Asset, Fair Value, Gross Asset | 15.8 | 19 | |
Other Current Liabilities | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Liability, Fair Value, Gross Liability | 3.6 | 3.6 | |
Other Noncurrent Liabilities | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Liability, Fair Value, Gross Liability | 16.4 | 19.9 | |
Fair Value Measured on a Recurring Basis | Other Current Assets | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Asset, Fair Value, Gross Asset | 14.7 | 12.7 | |
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset | [1] | (0.2) | (2) |
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Electric Commodity | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Asset, Fair Value, Gross Asset | 14.7 | 12.7 | |
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset | [1] | (0.2) | (2) |
Fair Value Measured on a Recurring Basis | Other Current Liabilities | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Liability, Fair Value, Gross Liability | 0 | 0 | |
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset | [1] | (0.2) | (2) |
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Other Derivative Instruments | Electric Commodity | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Liability, Fair Value, Gross Liability | 0 | 0 | |
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset | [1] | (0.2) | (2) |
Fair Value Measured on a Recurring Basis | Level 1 | Other Current Assets | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Asset, Fair Value, Gross Asset | 0 | 0 | |
Fair Value Measured on a Recurring Basis | Level 1 | Other Current Assets | Other Derivative Instruments | Electric Commodity | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Asset, Fair Value, Gross Asset | 0 | 0 | |
Fair Value Measured on a Recurring Basis | Level 1 | Other Current Liabilities | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Liability, Fair Value, Gross Liability | 0 | 0 | |
Fair Value Measured on a Recurring Basis | Level 1 | Other Current Liabilities | Other Derivative Instruments | Electric Commodity | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Liability, Fair Value, Gross Liability | 0 | 0 | |
Fair Value Measured on a Recurring Basis | Level 2 | Other Current Assets | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Asset, Fair Value, Gross Asset | 0 | 0 | |
Fair Value Measured on a Recurring Basis | Level 2 | Other Current Assets | Other Derivative Instruments | Electric Commodity | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Asset, Fair Value, Gross Asset | 0 | 0 | |
Fair Value Measured on a Recurring Basis | Level 2 | Other Current Liabilities | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Liability, Fair Value, Gross Liability | 0 | 0 | |
Fair Value Measured on a Recurring Basis | Level 2 | Other Current Liabilities | Other Derivative Instruments | Electric Commodity | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Liability, Fair Value, Gross Liability | 0 | 0 | |
Fair Value Measured on a Recurring Basis | Level 3 | Other Current Assets | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Asset, Fair Value, Gross Asset | 14.9 | 14.7 | |
Fair Value Measured on a Recurring Basis | Level 3 | Other Current Assets | Other Derivative Instruments | Electric Commodity | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Asset, Fair Value, Gross Asset | 14.9 | 14.7 | |
Fair Value Measured on a Recurring Basis | Level 3 | Other Current Liabilities | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Liability, Fair Value, Gross Liability | 0.2 | 2 | |
Fair Value Measured on a Recurring Basis | Level 3 | Other Current Liabilities | Other Derivative Instruments | Electric Commodity | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Liability, Fair Value, Gross Liability | 0.2 | 2 | |
Fair Value, Measurements, Nonrecurring | Other Current Assets | Purchased Power Agreements | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Asset, Fair Value, Gross Asset | [2] | 3.1 | 3.2 |
Fair Value, Measurements, Nonrecurring | Other Noncurrent Assets | Purchased Power Agreements | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Asset, Fair Value, Gross Asset | 15.8 | 19 | |
Fair Value, Measurements, Nonrecurring | Other Current Liabilities | Purchased Power Agreements | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Liability, Fair Value, Gross Liability | 3.6 | 3.6 | |
Fair Value, Measurements, Nonrecurring | Other Noncurrent Liabilities | Purchased Power Agreements | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Liability, Fair Value, Gross Liability | [2] | 16.4 | 19.9 |
Estimate of Fair Value Measurement [Member] | Fair Value Measured on a Recurring Basis | Other Current Assets | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Asset, Fair Value, Gross Asset | 14.9 | 14.7 | |
Estimate of Fair Value Measurement [Member] | Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Electric Commodity | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Asset, Fair Value, Gross Asset | 14.9 | 14.7 | |
Estimate of Fair Value Measurement [Member] | Fair Value Measured on a Recurring Basis | Other Current Liabilities | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Liability, Fair Value, Gross Liability | 0.2 | 2 | |
Estimate of Fair Value Measurement [Member] | Fair Value Measured on a Recurring Basis | Other Current Liabilities | Other Derivative Instruments | Electric Commodity | |||
Derivatives, Fair Value [Line Items] | |||
Derivative Liability, Fair Value, Gross Liability | $ 0.2 | $ 2 | |
[1] | SPS nets derivative instruments and related collateral in its balance sheet when supported by a legally enforceable master netting agreement, and all derivative instruments and related collateral amounts were subject to master netting agreements at Dec. 31, 2018 and 2017. At both Dec. 31, 2018 and 2017, derivative assets and liabilities include no obligations to return cash collateral or rights to reclaim cash collateral. The counterparty netting excludes settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements. | ||
[2] | During 2006, SPS qualified these contracts under the normal purchase exception. Based on this qualification, the contracts are no longer adjusted to fair value and the previous carrying value of these contracts will be amortized over the remaining contract lives along with the offsetting regulatory assets and liabilities. |
Fair Value of Financial Asset_7
Fair Value of Financial Assets and Liabilities, Changes in Level 3 Commodity Derivatives (Details) (Details) - Commodity Contract - USD ($) | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] | |||
Balance at beginning of period | $ 12,700,000 | $ 2,000,000 | $ 5,100,000 |
Purchases | 32,300,000 | 41,200,000 | 7,600,000 |
Settlements | (41,600,000) | (55,800,000) | (41,900,000) |
Gains (losses) recognized as regulatory assets | 11,300,000 | 25,300,000 | 31,200,000 |
Balance at end of period | 14,700,000 | 12,700,000 | 2,000,000 |
Transfers into Level 3 | 0 | 0 | 0 |
Transfers out of Level 3 | $ 0 | $ 0 | $ 0 |
Fair Value of Financial Asset_8
Fair Value of Financial Assets and Liabilities, Fair Value of Long-Term Debt (Details) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017 |
Carrying Amount | ||
Financial Liabilities, Balance Sheet Groupings [Abstract] | ||
Long-term debt, including current portion | $ 2,126.1 | $ 1,829.9 |
Fair Value | ||
Financial Liabilities, Balance Sheet Groupings [Abstract] | ||
Long-term debt, including current portion | $ 2,139.8 | $ 2,002 |
Benefit Plans and Other Postr_3
Benefit Plans and Other Postretirement Benefits, Pension Benefits (Details) $ in Millions | 12 Months Ended | |||
Dec. 31, 2019 | Dec. 31, 2018USD ($)Plan | Dec. 31, 2017USD ($)Plan | Dec. 31, 2016USD ($)Plan | |
Pension Plan [Member] | ||||
Pension Benefits [Abstract] | ||||
Total benefit obligation | $ 477.8 | $ 515.9 | $ 483.6 | |
Net benefit cost recognized for financial reporting | $ 14.8 | $ 14.9 | $ 17.4 | |
Minimum number of years historical achieved weighted average annual returns used to determine investment return assumptions (in years) | 20 years | |||
Expected average long-term rate of return on assets (as a percent) | 6.78% | 6.78% | 6.78% | |
Target Pension Asset Allocations [Abstract] | ||||
Target pension asset allocations (as a percent) | 100.00% | 100.00% | ||
Pension Plan [Member] | Domestic and international equity securities | ||||
Target Pension Asset Allocations [Abstract] | ||||
Target pension asset allocations (as a percent) | 35.00% | 34.00% | ||
Pension Plan [Member] | Long-Duration Fixed Income and Long-duration fixed income and interest rate swap securities | ||||
Target Pension Asset Allocations [Abstract] | ||||
Target pension asset allocations (as a percent) | 32.00% | 31.00% | ||
Pension Plan [Member] | Short-to-intermediate fixed income securities | ||||
Target Pension Asset Allocations [Abstract] | ||||
Target pension asset allocations (as a percent) | 16.00% | 19.00% | ||
Pension Plan [Member] | Alternative investments | ||||
Target Pension Asset Allocations [Abstract] | ||||
Target pension asset allocations (as a percent) | 15.00% | 14.00% | ||
Pension Plan [Member] | Cash | ||||
Target Pension Asset Allocations [Abstract] | ||||
Target pension asset allocations (as a percent) | 2.00% | 2.00% | ||
Supplemental Executive Retirement Plan (SERP) and Nonqualified Pension Plan | ||||
Pension Benefits [Abstract] | ||||
Total benefit obligation | $ 2 | |||
Net benefit cost recognized for financial reporting | 4 | $ 5 | ||
Parent Company [Member] | ||||
Defined Benefit Plan Disclosure [Line Items] | ||||
Expected contribution to postretirement health care plans during 2019 | 11 | |||
Target Pension Asset Allocations [Abstract] | ||||
Total contributions to Xcel Energy's postretirement health care plans during the year | $ 11 | $ 20 | $ 18 | |
Parent Company [Member] | Pension Plan [Member] | ||||
Defined Benefit Plan Disclosure [Line Items] | ||||
Defined benefit plan number of pension plans to which contributions were made | Plan | 4 | 4 | 4 | |
Parent Company [Member] | Supplemental Executive Retirement Plan (SERP) and Nonqualified Pension Plan | ||||
Pension Benefits [Abstract] | ||||
Total benefit obligation | $ 33 | $ 37 | ||
Scenario, Forecast [Member] | Pension Plan [Member] | ||||
Pension Benefits [Abstract] | ||||
Expected average long-term rate of return on assets for next fiscal year (as a percent) | 6.78% |
Benefit Plans and Other Postr_4
Benefit Plans and Other Postretirement Benefits, Fair Value of Pension Plan Assets (Details) - Pension Plan [Member] - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 |
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | $ 392.2 | $ 433.2 | $ 380.4 |
Plan asset investments measured at net asset value | 128.5 | 142.8 | |
Level 1 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 164.8 | 184.5 | |
Level 2 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 98.9 | 105.9 | |
Level 3 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Debt Securities [Member] | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 98.1 | 105.3 | |
Plan asset investments measured at net asset value | 0 | 0 | |
Debt Securities [Member] | Level 1 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Debt Securities [Member] | Level 2 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 98.1 | 105.3 | |
Debt Securities [Member] | Level 3 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Domestic and international equity securities | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 14.4 | 15.2 | |
Plan asset investments measured at net asset value | 0 | 0 | |
Domestic and international equity securities | Level 1 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 14.4 | 15.2 | |
Domestic and international equity securities | Level 2 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Domestic and international equity securities | Level 3 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Cash | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 21.6 | 26.9 | |
Plan asset investments measured at net asset value | 0 | 0 | |
Cash | Level 1 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 21.6 | 26.9 | |
Cash | Level 2 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Cash | Level 3 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Commingled funds | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 261.1 | 288.4 | |
Plan asset investments measured at net asset value | 132.5 | 142.7 | |
Commingled funds | Level 1 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 128.6 | 145.7 | |
Commingled funds | Level 2 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Commingled funds | Level 3 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Other | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | (3) | (2.6) | |
Plan asset investments measured at net asset value | (4) | 0.1 | |
Other | Level 1 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0.2 | (3.3) | |
Other | Level 2 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0.8 | 0.6 | |
Other | Level 3 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | $ 0 | $ 0 |
Benefit Plans and Other Postr_5
Benefit Plans and Other Postretirement Benefits, Pension Plan Benefit Obligations, Cash Flows and Benefit Costs (Details) | 1 Months Ended | 12 Months Ended | |||
Jan. 31, 2019USD ($) | Dec. 31, 2019USD ($) | Dec. 31, 2018USD ($)Plan | Dec. 31, 2017USD ($)Plan | Dec. 31, 2016USD ($)Plan | |
Defined Benefit Plan Disclosure [Line Items] | |||||
Defined Benefit Plan, Plan Assets, Payment for Settlement | $ 6,900,000 | $ 0 | |||
Operating and maintenance expenses | 282,700,000 | 285,400,000 | $ 265,500,000 | ||
Significant Assumptions Used to Measure Costs [Abstract] | |||||
Liability, Defined Benefit Plan, Noncurrent | (92,400,000) | (90,300,000) | |||
Pension Plan [Member] | |||||
Defined Benefit Plan Disclosure [Line Items] | |||||
Defined Benefit Plan, Plan Assets, Payment for Settlement | 3,300,000 | ||||
Accumulated Benefit Obligation at Dec. 31 | 445,800,000 | 478,800,000 | |||
Operating and maintenance expenses | 0 | ||||
Change in Projected Benefit Obligation [Roll Forward] | |||||
Obligation at Jan. 1 | $ 477,800,000 | $ 477,800,000 | 515,900,000 | 483,600,000 | |
Service cost | 9,700,000 | 9,800,000 | 9,800,000 | ||
Interest cost | 18,400,000 | 19,700,000 | 21,200,000 | ||
Plan amendments | 0 | (1,000,000) | |||
Actuarial loss | (34,800,000) | 31,200,000 | |||
Benefit payments | (31,400,000) | (27,400,000) | |||
Obligation at Dec. 31 | 477,800,000 | 515,900,000 | 483,600,000 | ||
Change in Fair Value of Plan Assets [Roll Forward] | |||||
Fair value of plan assets at Jan. 1 | 392,200,000 | 392,200,000 | 433,200,000 | 380,400,000 | |
Actual return on plan assets | (17,600,000) | 56,700,000 | |||
Employer contributions | 8,000,000 | 23,500,000 | |||
Benefit payments | (31,400,000) | (27,400,000) | |||
Fair value of plan assets at Dec. 31 | 392,200,000 | 433,200,000 | 380,400,000 | ||
Funded Status of Plans at Dec. 31 [Abstract] | |||||
Funded status | (85,600,000) | (82,700,000) | |||
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost Have Been Recorded as Follows Based Upon Expected Recovery Rates [Abstract] | |||||
Net loss | 230,900,000 | 237,000,000 | |||
Prior service credit | (1,200,000) | (1,300,000) | |||
Total | 229,700,000 | 235,700,000 | |||
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost Have Been Recorded as Follows Based Upon Expected Recovery in Rates [Abstract] | |||||
Current regulatory assets | 12,900,000 | 13,900,000 | |||
Noncurrent regulatory assets | 216,800,000 | 221,800,000 | |||
Amounts Not Yet Recognized As Components Of Net Periodic Benefit Cost Recorded As Current Regulatory Liabilities | 0 | 0 | |||
Amounts Not Yet Recognized As Components Of Net Periodic Benefit Cost Recorded As Noncurrent Regulatory Liabilities | 0 | 0 | |||
Total | $ 229,700,000 | $ 235,700,000 | |||
Significant Assumptions Used to Measure Benefit Obligations [Abstract] | |||||
Discount rate for year-end valuation (as a percent) | 4.31% | 3.63% | |||
Expected average long-term increase in compensation level (as a percent) | 3.75% | 3.75% | |||
Mortality table | RP2014 | RP2014 | |||
Cash Flows [Abstract] | |||||
Payment for Pension Benefits | $ 8,000,000 | $ 24,000,000 | 18,000,000 | ||
Components of Net Periodic Benefit Cost (Credit) [Abstract] | |||||
Service cost | 9,700,000 | 9,800,000 | 9,800,000 | ||
Interest cost | 18,400,000 | 19,700,000 | 21,200,000 | ||
Expected return on plan assets | (28,300,000) | (27,900,000) | (27,600,000) | ||
Amortization of prior service cost | (100,000) | 0 | 0 | ||
Amortization of net loss | 14,100,000 | 13,000,000 | 12,000,000 | ||
Net periodic pension cost | 17,000,000 | 14,600,000 | 15,400,000 | ||
Net benefit cost recognized for financial reporting | $ 14,800,000 | $ 14,900,000 | $ 17,400,000 | ||
Significant Assumptions Used to Measure Costs [Abstract] | |||||
Discount rate (as a percent) | 3.63% | 4.13% | 4.66% | ||
Expected average long-term increase in compensation level (as a percent) | 3.75% | 3.75% | 4.00% | ||
Expected average long-term rate of return on assets (as a percent) | 6.78% | 6.78% | 6.78% | ||
Plan participant's contributions | $ 0 | $ 0 | |||
Plan participant's contributions | 0 | 0 | |||
Liability, Defined Benefit Plan, Noncurrent | (85,600,000) | (82,700,000) | |||
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position | (85,600,000) | (82,700,000) | |||
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement | 3,200,000 | 0 | $ 0 | ||
Defined Benefit Plan, Costs Not Recognized Due To Regulation | $ (2,200,000) | $ 300,000 | $ 2,000,000 | ||
Pension Plan [Member] | Subsequent Event | |||||
Cash Flows [Abstract] | |||||
Payment for Pension Benefits | $ 17,000,000 | ||||
Parent Company [Member] | Pension Plan [Member] | |||||
Cash Flows [Abstract] | |||||
Number of pension plans to which contributions were made | Plan | 4 | 4 | 4 | ||
Payment for Pension Benefits | $ 150,000,000 | $ 150,000,000 | $ 162,000,000 | $ 125,000,000 |
Benefit Plans and Other Postr_6
Benefit Plans and Other Postretirement Benefits, Defined Contribution Plans (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Defined Contribution Plans [Abstract] | |||
Contributions to 401(k) and other defined contribution plans | $ 3 | $ 3 | $ 3 |
Benefit Plans and Other Postr_7
Benefit Plans and Other Postretirement Benefits, Postretirement Health Care Benefits (Details) - Other Postretirement Benefits Plan [Member] | Dec. 31, 2018 | Dec. 31, 2017 |
Postretirement Health Care Benefits [Abstract] | ||
Target pension asset allocations (as a percent) | 100.00% | 100.00% |
Domestic and international equity securities | ||
Postretirement Health Care Benefits [Abstract] | ||
Target pension asset allocations (as a percent) | 18.00% | 24.00% |
Long-Duration Fixed Income and Long-duration fixed income and interest rate swap securities | ||
Postretirement Health Care Benefits [Abstract] | ||
Target pension asset allocations (as a percent) | 0.00% | 0.00% |
Short-to-intermediate fixed income securities | ||
Postretirement Health Care Benefits [Abstract] | ||
Target pension asset allocations (as a percent) | 70.00% | 60.00% |
Alternative investments | ||
Postretirement Health Care Benefits [Abstract] | ||
Target pension asset allocations (as a percent) | 8.00% | 9.00% |
Cash | ||
Postretirement Health Care Benefits [Abstract] | ||
Target pension asset allocations (as a percent) | 4.00% | 7.00% |
Benefit Plans and Other Postr_8
Benefit Plans and Other Postretirement Benefits, Fair Value of Postretirement Benefit Plan Assets (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Other Postretirement Benefits Plan [Member] | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | $ 40 | $ 44.1 | $ 42.3 |
Plan assets at net asset value | 3.8 | 0 | |
Other Postretirement Benefits Plan [Member] | Level 1 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 14.6 | 20.2 | |
Other Postretirement Benefits Plan [Member] | Level 2 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 21.6 | 23.9 | |
Other Postretirement Benefits Plan [Member] | Level 3 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Debt Securities [Member] | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 17.2 | 19 | |
Plan assets at net asset value | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Debt Securities [Member] | Level 1 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Debt Securities [Member] | Level 2 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 17.2 | 19 | |
Other Postretirement Benefits Plan [Member] | Debt Securities [Member] | Level 3 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Cash | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 1.8 | 2.8 | |
Plan assets at net asset value | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Cash | Level 1 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 1.8 | 2.8 | |
Other Postretirement Benefits Plan [Member] | Cash | Level 2 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Cash | Level 3 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Insurance contracts | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 4.3 | 4.7 | |
Plan assets at net asset value | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Insurance contracts | Level 1 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Insurance contracts | Level 2 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 4.3 | 4.7 | |
Other Postretirement Benefits Plan [Member] | Insurance contracts | Level 3 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Other | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0.1 | 0.2 | |
Plan assets at net asset value | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Other | Level 1 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Other | Level 2 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0.1 | 0.2 | |
Other Postretirement Benefits Plan [Member] | Other | Level 3 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Commingled funds | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 16.6 | 14.1 | |
Plan assets at net asset value | 3.8 | 0 | |
Other Postretirement Benefits Plan [Member] | Commingled funds | Level 1 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 12.8 | 14.1 | |
Other Postretirement Benefits Plan [Member] | Commingled funds | Level 2 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Commingled funds | Level 3 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Domestic and international equity securities | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 3.3 | |
Plan assets at net asset value | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Domestic and international equity securities | Level 1 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 3.3 | |
Other Postretirement Benefits Plan [Member] | Domestic and international equity securities | Level 2 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Other Postretirement Benefits Plan [Member] | Domestic and international equity securities | Level 3 | |||
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract] | |||
Fair value of plan assets | 0 | 0 | |
Parent Company [Member] | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Payment for Other Postretirement Benefits | $ 11 | $ 20 | $ 18 |
Benefit Plans and Other Postr_9
Benefit Plans and Other Postretirement Benefits, Postretirement Benefit Plan Benefit Obligations, Cash Flows and Benefit Costs (Details) - USD ($) $ in Millions | 12 Months Ended | |||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Significant Assumptions Used to Measure Costs [Abstract] | ||||
Liability, Defined Benefit Plan, Noncurrent | $ (92.4) | $ (90.3) | ||
Other Postretirement Benefits Plan [Member] | ||||
Defined Benefit Plan Disclosure [Line Items] | ||||
Plan amendments | 0 | 0 | ||
Change in Projected Benefit Obligation [Roll Forward] | ||||
Obligation at Jan. 1 | $ 41.8 | 47 | 41.9 | |
Service cost | 1.1 | 0.9 | $ 0.8 | |
Interest cost | 1.6 | 1.7 | 1.8 | |
Plan participant's contributions | 0.6 | 0.6 | ||
Actuarial loss | (5.1) | 4.7 | ||
Benefit payments | (3.4) | (2.8) | ||
Obligation at Dec. 31 | 41.8 | 47 | 41.9 | |
Change in Fair Value of Plan Assets [Roll Forward] | ||||
Fair value of plan assets at Jan. 1 | 40 | 44.1 | 42.3 | |
Actual return on plan assets | (1.3) | 3.8 | ||
Plan participant's contributions | 0.6 | 0.6 | ||
Employer contributions | 0 | 0.2 | ||
Benefit payments | (3.4) | (2.8) | ||
Fair value of plan assets at Dec. 31 | 40 | 44.1 | 42.3 | |
Funded Status of Plans at Dec. 31 [Abstract] | ||||
Funded status | (1.8) | (2.9) | ||
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost Have Been Recorded as Follows Based Upon Expected Recovery Rates [Abstract] | ||||
Net loss | (9.6) | (8.6) | ||
Prior service credit | (1.8) | (2.2) | ||
Total | (11.4) | (10.8) | ||
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost (Credit) Have Been Recorded as Follows Based Upon Expected Recovery in Rates [Abstract] | ||||
Amounts Not Yet Recognized As Components Of Net Periodic Benefit Cost Recorded As Current Regulatory Assets | 0 | 0 | ||
Amounts Not Yet Recognized As Components Of Net Periodic Benefit Cost Recorded As Noncurrent Regulatory Assets | 0 | 0 | ||
Current regulatory liabilities | (0.9) | (0.8) | ||
Noncurrent regulatory liabilities | (10.5) | (10) | ||
Total | $ (11.4) | $ (10.8) | ||
Significant Assumptions Used to Measure Benefit Obligations [Abstract] | ||||
Discount rate for year-end valuation (as a percent) | 4.32% | 3.62% | ||
Mortality table | RP2014 | RP2014 | ||
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Pre-65 | 6.50% | 7.00% | ||
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Post-65 | 5.30% | 5.50% | ||
Ultimate health care trend assumption rate (as a percent) | 4.50% | 4.50% | ||
Period until ultimate trend rate is reached (in years) | 4 | 5 | ||
Components of Net Periodic Benefit Cost (Credit) [Abstract] | ||||
Service cost | $ 1.1 | $ 0.9 | 0.8 | |
Interest cost | 1.6 | 1.7 | 1.8 | |
Expected return on plan assets | (2.5) | (2.4) | (2.4) | |
Amortization of prior service cost | (0.4) | (0.4) | (0.4) | |
Amortization of net loss | (0.4) | (0.6) | (0.6) | |
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement | 0 | 0 | 0 | |
Net periodic pension cost | $ (0.6) | $ (0.8) | $ (0.8) | |
Significant Assumptions Used to Measure Costs [Abstract] | ||||
Discount rate (as a percent) | 3.62% | 4.13% | 4.65% | |
Expected average long-term increase in compensation level (as a percent) | 0.00% | 0.00% | 0.00% | |
Expected average long-term rate of return on assets (as a percent) | 5.80% | 5.80% | 5.80% | |
Liability, Defined Benefit Plan, Noncurrent | $ (1.8) | $ (2.9) | ||
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position | (1.8) | (2.9) | ||
Defined Benefit Plan, Costs Not Recognized Due To Regulation | 0 | 0 | $ 0 | |
Net benefit cost recognized for financial reporting | (0.6) | (0.8) | (0.8) | |
Pension Plan [Member] | ||||
Defined Benefit Plan Disclosure [Line Items] | ||||
Payment for Pension Benefits | 8 | 24 | 18 | |
Plan amendments | 0 | (1) | ||
Change in Projected Benefit Obligation [Roll Forward] | ||||
Obligation at Jan. 1 | 477.8 | 515.9 | 483.6 | |
Service cost | 9.7 | 9.8 | 9.8 | |
Interest cost | 18.4 | 19.7 | 21.2 | |
Plan participant's contributions | 0 | 0 | ||
Actuarial loss | (34.8) | 31.2 | ||
Benefit payments | (31.4) | (27.4) | ||
Obligation at Dec. 31 | 477.8 | 515.9 | 483.6 | |
Change in Fair Value of Plan Assets [Roll Forward] | ||||
Fair value of plan assets at Jan. 1 | 392.2 | 433.2 | 380.4 | |
Actual return on plan assets | (17.6) | 56.7 | ||
Plan participant's contributions | 0 | 0 | ||
Employer contributions | 8 | 23.5 | ||
Benefit payments | (31.4) | (27.4) | ||
Fair value of plan assets at Dec. 31 | 392.2 | 433.2 | 380.4 | |
Funded Status of Plans at Dec. 31 [Abstract] | ||||
Funded status | (85.6) | (82.7) | ||
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost Have Been Recorded as Follows Based Upon Expected Recovery Rates [Abstract] | ||||
Net loss | 230.9 | 237 | ||
Prior service credit | (1.2) | (1.3) | ||
Total | 229.7 | 235.7 | ||
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost (Credit) Have Been Recorded as Follows Based Upon Expected Recovery in Rates [Abstract] | ||||
Amounts Not Yet Recognized As Components Of Net Periodic Benefit Cost Recorded As Current Regulatory Assets | 12.9 | 13.9 | ||
Amounts Not Yet Recognized As Components Of Net Periodic Benefit Cost Recorded As Noncurrent Regulatory Assets | 216.8 | 221.8 | ||
Current regulatory liabilities | 0 | 0 | ||
Noncurrent regulatory liabilities | 0 | 0 | ||
Total | $ 229.7 | $ 235.7 | ||
Significant Assumptions Used to Measure Benefit Obligations [Abstract] | ||||
Discount rate for year-end valuation (as a percent) | 4.31% | 3.63% | ||
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase | 3.75% | 3.75% | ||
Mortality table | RP2014 | RP2014 | ||
Components of Net Periodic Benefit Cost (Credit) [Abstract] | ||||
Service cost | $ 9.7 | $ 9.8 | 9.8 | |
Interest cost | 18.4 | 19.7 | 21.2 | |
Expected return on plan assets | (28.3) | (27.9) | (27.6) | |
Amortization of prior service cost | (0.1) | 0 | 0 | |
Amortization of net loss | 14.1 | 13 | 12 | |
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement | (3.2) | 0 | 0 | |
Net periodic pension cost | $ 17 | $ 14.6 | $ 15.4 | |
Significant Assumptions Used to Measure Costs [Abstract] | ||||
Discount rate (as a percent) | 3.63% | 4.13% | 4.66% | |
Expected average long-term increase in compensation level (as a percent) | 3.75% | 3.75% | 4.00% | |
Expected average long-term rate of return on assets (as a percent) | 6.78% | 6.78% | 6.78% | |
Liability, Defined Benefit Plan, Noncurrent | $ (85.6) | $ (82.7) | ||
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position | (85.6) | (82.7) | ||
Defined Benefit Plan, Costs Not Recognized Due To Regulation | 2.2 | (0.3) | $ (2) | |
Net benefit cost recognized for financial reporting | 14.8 | 14.9 | 17.4 | |
Parent Company [Member] | ||||
Cash Flows [Abstract] | ||||
Total contributions to Xcel Energy's postretirement health care plans during the year | 11 | 20 | 18 | |
Expected contribution to postretirement health care plans during 2019 | 11 | |||
Parent Company [Member] | Pension Plan [Member] | ||||
Defined Benefit Plan Disclosure [Line Items] | ||||
Payment for Pension Benefits | $ 150 | $ 150 | $ 162 | $ 125 |
Benefit Plans and Other Post_10
Benefit Plans and Other Postretirement Benefits, Projected Benefit Payments (Details) $ in Millions | Dec. 31, 2018USD ($) |
Pension Plan [Member] | |
Defined Benefit Plan, Gross Projected Benefit Payments [Abstract] | |
2,019 | $ 29.7 |
2,020 | 30 |
2,021 | 29.3 |
2,022 | 30.8 |
2,023 | 30.8 |
2024-2028 | 156.2 |
Other Postretirement Benefits Plan [Member] | |
Defined Benefit Plan, Gross Projected Benefit Payments [Abstract] | |
2,019 | 3.2 |
2,020 | 3.1 |
2,021 | 3.2 |
2,022 | 3.2 |
2,023 | 3.2 |
2024-2028 | 14.4 |
Expected Medicare Part D Subsidies [Abstract] | |
2,019 | 0 |
2,020 | 0 |
2,021 | 0 |
2,022 | 0 |
2,023 | 0 |
2024-2028 | 0.2 |
Defined Benefit Plan, Net Projected Benefit Payments [Abstract] | |
2,019 | 3.2 |
2,020 | 3.1 |
2,021 | 3.2 |
2,022 | 3.2 |
2,023 | 3.2 |
2024-2028 | $ 14.2 |
Commitments and Contingencies,
Commitments and Contingencies, Fuel Contracts (Details) $ in Thousands | 12 Months Ended |
Dec. 31, 2018USD ($) | |
Coal | |
Fuel Contracts [Abstract] | |
2,019 | $ 127,300 |
2,020 | 83,900 |
2,021 | 41,000 |
2,022 | 41,200 |
2,023 | 0 |
Thereafter | 0 |
Total | 293,400 |
Natural Gas Supply [Member] | |
Fuel Contracts [Abstract] | |
2,019 | 20,300 |
2,020 | 0 |
2,021 | 0 |
2,022 | 0 |
2,023 | 0 |
Thereafter | 0 |
Total | 20,300 |
Natural Gas Storage and Transportation [Member] | |
Fuel Contracts [Abstract] | |
2,019 | 30,300 |
2,020 | 30,300 |
2,021 | 25,200 |
2,022 | 19,300 |
2,023 | 14,100 |
Thereafter | 33,600 |
Total | $ 152,800 |
Minimum | |
Unrecorded Unconditional Purchase Obligation [Line Items] | |
Fuel Contract Expiration Date | 2,019 |
Maximum | |
Unrecorded Unconditional Purchase Obligation [Line Items] | |
Fuel Contract Expiration Date | 2,033 |
Commitments and Contingencies_2
Commitments and Contingencies, Purchased Power Agreements (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Long-term Contract for Purchase of Electric Power [Line Items] | |||
Operating Lease Purchase Power Agreement Expiration Date | 2,033 | ||
Capacity | |||
Purchased Power Agreements (PPAs) [Abstract] | |||
Payments for capacity | $ 57.6 | $ 58.4 | $ 56.8 |
Estimated Future Payments Under PPAs [Abstract] | |||
2,019 | 20.3 | ||
2,020 | 12 | ||
2,021 | 12.2 | ||
2,022 | 12.4 | ||
2,023 | 12.6 | ||
Thereafter | 5.7 | ||
Total | $ 75.2 |
Commitments and Contingencies_3
Commitments and Contingencies, Leases (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Operating Leased Assets [Line Items] | |||
Operating Lease Purchase Power Agreement Expiration Date | 2,033 | ||
Operating Leases, Future Minimum Payments Due [Abstract] | |||
2,018 | $ 51.9 | ||
2,019 | 51.4 | ||
2,020 | 51.3 | ||
2,021 | 51.3 | ||
2,022 | 51.3 | ||
Thereafter | 507.1 | ||
Office Space and Other Equipment | |||
Operating Leases [Abstract] | |||
Total expenses under operating lease obligations | 59 | $ 57.8 | $ 56.6 |
Operating Leases, Future Minimum Payments Due [Abstract] | |||
2,018 | 5.2 | ||
2,019 | 5.2 | ||
2,020 | 5.1 | ||
2,021 | 5.1 | ||
2,022 | 5.1 | ||
Thereafter | 56.3 | ||
Purchased Power Agreements | |||
Operating Leases [Abstract] | |||
Payments for capacity | 51.1 | $ 51.4 | $ 50.6 |
Operating Leases, Future Minimum Payments Due [Abstract] | |||
2,018 | 46.7 | ||
2,019 | 46.2 | ||
2,020 | 46.2 | ||
2,021 | 46.2 | ||
2,022 | 46.2 | ||
Thereafter | $ 450.8 |
Commitments and Contingencies_4
Commitments and Contingencies, Variable Interest Entities (Details) - MW | 12 Months Ended | |
Dec. 31, 2018 | Dec. 31, 2017 | |
Independent Power Producing Entities | ||
Purchased Power Agreements [Abstract] | ||
Generating capacity (in MW) | 1,197 | 897 |
VIE Purchase Power Agreement Expiration | 2,041 | |
Tolk Station Power Plant | ||
Fuel Contracts [Abstract] | ||
Coal Supply Agreement Expiration | 2,022 |
Commitments and Contingencies C
Commitments and Contingencies Commitments and Contingencies, Environmental Contingencies - Site Contingencies (Details) - Other MGP, Landfill, or Disposal Sites $ in Millions | Dec. 31, 2018USD ($) | Dec. 31, 2017USD ($) |
Site Contingency [Line Items] | ||
Number of identified MGP sites under current investigation and/or remediation | 1 | |
Accrual for Environmental Loss Contingencies | $ 0.1 | $ 0.1 |
Commitments and Contingencies_5
Commitments and Contingencies, Environmental Contingencies (Details) $ in Millions | 12 Months Ended |
Dec. 31, 2018USD ($) | |
Harrington Units 1 and 2 | Implementation of the National Ambient Air Quality Standard for Sulfur Dioxide | |
Environmental Requirements [Abstract] | |
Number of Years Unclassifiable Areas Will Be Monitored | 3 years |
Tolk Units 1 and 2 | Capital Commitments | Regional Haze Rules | |
Environmental Requirements [Abstract] | |
Liability for Estimated Cost to Comply with Regulation | $ 600 |
Commitments and Contingencies_6
Commitments and Contingencies, Asset Retirement Obligations (Details) - USD ($) | 12 Months Ended | |
Dec. 31, 2018 | Dec. 31, 2017 | |
Asset Retirement Obligations [Line Items] | ||
Asset Retirement Obligation, Liabilities Settled | $ 0 | $ 0 |
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
Beginning balance | 28,500,000 | 28,700,000 |
Liabilities Incurred | 0 | 0 |
Accretion | 1,600,000 | 1,500,000 |
Cash flow revisions | 2,300,000 | (1,700,000) |
Ending balance | 32,400,000 | 28,500,000 |
Electric Plant Steam Production Asbestos | ||
Asset Retirement Obligations [Line Items] | ||
Asset Retirement Obligation, Liabilities Settled | 0 | 0 |
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
Beginning balance | 20,300,000 | 20,700,000 |
Liabilities Incurred | 0 | 0 |
Accretion | 1,200,000 | 1,300,000 |
Cash flow revisions | 500,000 | (1,700,000) |
Ending balance | 22,000,000 | 20,300,000 |
Electric Plant Electric Distribution | ||
Asset Retirement Obligations [Line Items] | ||
Asset Retirement Obligation, Liabilities Settled | 0 | 0 |
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
Beginning balance | 7,000,000 | 6,800,000 |
Liabilities Incurred | 0 | 0 |
Accretion | 300,000 | 200,000 |
Cash flow revisions | 1,800,000 | 0 |
Ending balance | 9,100,000 | 7,000,000 |
Electric Plant Other | ||
Asset Retirement Obligations [Line Items] | ||
Asset Retirement Obligation, Liabilities Settled | 0 | 0 |
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
Beginning balance | 1,200,000 | 1,200,000 |
Liabilities Incurred | 0 | 0 |
Accretion | 100,000 | 0 |
Cash flow revisions | 0 | 0 |
Ending balance | $ 1,300,000 | $ 1,200,000 |
Commitments and Contingencies_7
Commitments and Contingencies, Removal Costs (Details) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017 |
Plant Removal Costs | ||
Regulatory Liabilities [Line Items] | ||
Regulatory Liabilities | $ 188 | $ 197 |
Commitments and Contingencies_8
Commitments and Contingencies, Legal Contingencies (Details) - USD ($) $ in Millions | 1 Months Ended | 12 Months Ended | |
Aug. 31, 2018 | Dec. 31, 2018 | Dec. 31, 2016 | |
Loss Contingencies [Line Items] | |||
Public Utilities, Amount proposed changes would increase wholesale transmission revenues | $ 9.4 | ||
Legal Contingencies [Abstract] | |||
Public Utilities, Amount of proposed changes would be recoverable | $ 4.4 | ||
Southwest Power Pool (SPP) [Member] | SPP Open Access Transmission Tariff Upgrade Costs [Member] | |||
Loss Contingencies [Line Items] | |||
Public Utilities, Annual Transmission Revenue Requirement Increase | $ 9.5 | ||
Legal Contingencies [Abstract] | |||
Public Utilities, Annual Transmission Revenue Requirement Increase (SPS) | 6 | ||
Public Utilities, Annual Transmission Revenue Requirement (Other Utilities) | $ 3.5 | ||
SPS [Member] | Southwest Power Pool (SPP) [Member] | SPP Open Access Transmission Tariff Upgrade Costs [Member] | |||
Loss Contingencies [Line Items] | |||
Public Utilities, Billed Charges For Transmission Service Upgrades | $ 13 |
Other Comprehensive Income (Det
Other Comprehensive Income (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Accumulated other comprehensive loss at beginning of period | $ 2,130,300 | ||
(Gains) losses reclassified from net accumulated other comprehensive loss | 0 | $ (100) | |
Net current period other comprehensive income (loss) | 100 | 100 | |
Adoption of ASU No. 2018-02 | 0 | ||
Accumulated other comprehensive loss at end of period | 2,536,600 | 2,130,300 | |
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax | 0 | 0 | $ (100) |
Income Tax Expense (Benefit) | 38,900 | 68,400 | 82,100 |
AOCI Attributable to Parent | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Accumulated other comprehensive loss at beginning of period | (1,500) | (1,300) | |
Adoption of ASU No. 2018-02 | (300) | ||
Accumulated other comprehensive loss at end of period | (1,400) | (1,500) | (1,300) |
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Accumulated other comprehensive loss at beginning of period | (700) | (600) | |
(Gains) losses reclassified from net accumulated other comprehensive loss | 0 | (100) | |
Net current period other comprehensive income (loss) | 0 | 100 | |
Adoption of ASU No. 2018-02 | (200) | ||
Accumulated other comprehensive loss at end of period | (700) | (700) | (600) |
Reclassification from AOCI, Current Period, Tax | 0 | 0 | |
Gains and Losses on Cash Flow Hedges | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Accumulated other comprehensive loss at beginning of period | (800) | (700) | |
(Gains) losses reclassified from net accumulated other comprehensive loss | 0 | 0 | |
Net current period other comprehensive income (loss) | 100 | 0 | |
Adoption of ASU No. 2018-02 | (100) | ||
Accumulated other comprehensive loss at end of period | (700) | (800) | $ (700) |
Interest Rate Swap | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
(Gains) losses reclassified from net accumulated other comprehensive loss | (100) | 0 | |
Interest Rate Swap | Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
(Gains) losses reclassified from net accumulated other comprehensive loss | 0 | 0 | |
Interest Rate Swap | Gains and Losses on Cash Flow Hedges | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
(Gains) losses reclassified from net accumulated other comprehensive loss | (100) | 0 | |
Reclassification out of Accumulated Other Comprehensive Income [Member] | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Income Tax Expense (Benefit) | 0 | 0 | |
Reclassification from AOCI, Current Period, Tax | 0 | 0 | |
Reclassification out of Accumulated Other Comprehensive Income [Member] | Gains and Losses on Cash Flow Hedges | |||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | |||
Income Tax Expense (Benefit) | $ 0 | $ 100 |
Related Party Transactions (Det
Related Party Transactions (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Operating expenses [Abstract] | |||
Purchased power | $ 0 | $ 1.4 | $ 8.8 |
Other operating expenses - paid to Xcel Energy Services Inc. | 195.1 | 196.6 | 188.2 |
Interest expense | 0.6 | 0 | $ 0.2 |
Accounts Receivable and Payable with Affiliates [Abstract] | |||
Accounts receivable | 10.5 | 1.3 | |
Accounts payable | 19.9 | 22.6 | |
NSP-Minnesota | |||
Accounts Receivable and Payable with Affiliates [Abstract] | |||
Accounts receivable | 4.7 | 1 | |
Accounts payable | 0 | 0 | |
PSCo | |||
Accounts Receivable and Payable with Affiliates [Abstract] | |||
Accounts receivable | 0 | 0 | |
Accounts payable | 0.7 | 0.3 | |
Other Subsidiaries of Xcel Energy Inc. | |||
Accounts Receivable and Payable with Affiliates [Abstract] | |||
Accounts receivable | 5.8 | 0.3 | |
Accounts payable | $ 19.2 | $ 22.3 |
Summarized Quarterly Financia_3
Summarized Quarterly Financial Data (Unaudited) (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended | |||||||||||||||||
Dec. 31, 2017 | Sep. 30, 2017 | Jun. 30, 2017 | Mar. 31, 2017 | Dec. 31, 2016 | Sep. 30, 2016 | Jun. 30, 2016 | Mar. 31, 2016 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |||||||||
Quarterly Financial Information Disclosure [Abstract] | |||||||||||||||||||
Revenues | $ 464,600 | $ 540,100 | $ 481,300 | $ 447,200 | $ 426,500 | $ 551,600 | $ 479,800 | $ 460,100 | $ 1,933,200 | $ 1,918,000 | $ 1,851,000 | ||||||||
Operating income | 56,000 | [1] | 111,000 | [1] | 87,600 | [1] | 57,100 | [1] | 43,400 | [1] | 123,100 | [1] | 75,200 | [1] | 59,200 | [1] | 311,700 | 300,900 | 311,300 |
Net income | $ 40,200 | $ 81,500 | $ 58,500 | $ 33,100 | $ 31,000 | $ 67,800 | $ 35,300 | $ 25,100 | $ 213,300 | $ 159,200 | $ 152,200 | ||||||||
[1] | (a) In 2018, SPS implemented ASU No. 2017-07 related to net periodic benefit cost, which resulted in retrospective reclassification of pension costs from O&M expense to other income. |
Schedule II, Valuation and Qu_2
Schedule II, Valuation and Qualifying Accounts (Details) - Allowance for Bad Debts - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | |||
Balance at Jan. 1 | $ 6.4 | $ 6.4 | $ 5.9 |
Charged to costs and expenses | 4.9 | 5.1 | 6.1 |
Charged to other accounts | 1 | 1.2 | 0.9 |
Deductions from reserves | (6.7) | (6.3) | (6.5) |
Balance at Dec. 31 | $ 5.6 | $ 6.4 | $ 6.4 |