Document And Entity Information
Document And Entity Information - USD ($) $ in Billions | 12 Months Ended | ||
Dec. 31, 2017 | Feb. 09, 2018 | Jun. 30, 2017 | |
Document Information [Line Items] | |||
Entity Registrant Name | ONE Gas, Inc. | ||
Entity Central Index Key | 1,587,732 | ||
Current Fiscal Year End Date | --12-31 | ||
Entity Well-known Seasoned Issuer | Yes | ||
Entity Voluntary Filers | No | ||
Entity Current Reporting Status | Yes | ||
Entity Filer Category | Large Accelerated Filer | ||
Entity Public Float | $ 3.5 | ||
Entity Common Stock, Shares Outstanding | 52,315,980 | ||
Document Fiscal Year Focus | 2,017 | ||
Document Fiscal Period Focus | FY | ||
Document Type | 10-K | ||
Amendment Flag | false | ||
Document Period End Date | Dec. 31, 2017 |
STATEMENTS OF INCOME
STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Gross Margin | |||
Revenues | $ 1,539,633 | $ 1,427,232 | $ 1,547,692 |
Cost of natural gas | 614,501 | 541,797 | 705,959 |
Net margin | 925,132 | 885,435 | 841,733 |
Operating expenses | |||
Operations and maintenance | 416,542 | 417,142 | 414,476 |
Depreciation and amortization | 151,889 | 143,829 | 133,023 |
General taxes | 57,225 | 55,344 | 55,105 |
Total operating expenses | 625,656 | 616,315 | 602,604 |
Operating income | 299,476 | 269,120 | 239,129 |
Other income | 4,217 | 1,447 | 263 |
Other expense | (1,490) | (1,490) | (2,813) |
Interest expense, net | (46,065) | (43,739) | (44,570) |
Income before income taxes | 256,138 | 225,338 | 192,009 |
Income taxes | (93,143) | (85,243) | (72,979) |
Net income | $ 162,995 | $ 140,095 | $ 119,030 |
Earnings per share | |||
Basic | $ 3.10 | $ 2.67 | $ 2.26 |
Diluted | $ 3.08 | $ 2.65 | $ 2.24 |
Average shares (thousands) | |||
Basic | 52,527 | 52,453 | 52,578 |
Diluted | 52,979 | 52,963 | 53,254 |
Dividends declared per share of stock | $ 1.68 | $ 1.40 | $ 1.20 |
STATEMENTS OF COMPREHENSIVE INC
STATEMENTS OF COMPREHENSIVE INCOME STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Net income | $ 162,995 | $ 140,095 | $ 119,030 |
Other Comprehensive Income (Loss), Net of Tax [Abstract] | |||
Change in pension and other postretirement benefit plans liability, net of tax of $486, $197, and $(483), respectively | (778) | (314) | 773 |
Other comprehensive income (loss), net of tax | (778) | (314) | 773 |
Comprehensive income | $ 162,217 | $ 139,781 | $ 119,803 |
STATEMENTS OF COMPREHENSIVE IN4
STATEMENTS OF COMPREHENSIVE INCOME (Parentheticals) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
STATEMENTS OF COMPREHENSIVE INCOME [Abstract] | |||
Pension and other postretirement benefit plans, Tax | $ 486 | $ 197 | $ (483) |
BALANCE SHEETS
BALANCE SHEETS - USD ($) $ in Thousands | Dec. 31, 2017 | Dec. 31, 2016 |
Property, plant and equipment | ||
Property, plant and equipment | $ 5,713,912 | $ 5,404,168 |
Accumulated depreciation and amortization | 1,706,327 | 1,672,548 |
Net property, plant and equipment | 4,007,585 | 3,731,620 |
Current assets | ||
Cash and cash equivalents | 14,413 | 14,663 |
Accounts receivable, net | 298,768 | 290,944 |
Materials and supplies | 39,672 | 34,084 |
Natural gas in storage | 130,154 | 125,432 |
Regulatory assets | 88,180 | 83,146 |
Other current assets | 17,807 | 20,654 |
Total current assets | 588,994 | 568,923 |
Goodwill and other assets | ||
Regulatory assets | 405,189 | 440,522 |
Goodwill | 157,953 | 157,953 |
Other assets | 47,157 | 43,773 |
Total goodwill and other assets | 610,299 | 642,248 |
Total assets | 5,206,878 | 4,942,791 |
Equity and long-term debt | ||
Common stock, $0.01 par value: authorized 250,000,000 shares; issued 52,598,005 shares and outstanding 52,312,516 shares at December 31, 2017; issued 52,598,005 shares and outstanding 52,283,260 shares at December 31, 2016 | 526 | 526 |
Paid-in capital | 1,737,551 | 1,749,574 |
Retained earnings | 246,121 | 161,021 |
Accumulated other comprehensive income (loss) | (5,493) | (4,715) |
Treasury stock, at cost: 285,489 shares at December 31, 2017 and 314,745 shares at December 31, 2016 | (18,496) | (18,126) |
Total equity | 1,960,209 | 1,888,280 |
Long-term debt, excluding current maturities, and net of issuance costs of $8,033 and $8,851, respectively | 1,193,257 | 1,192,446 |
Total equity and long-term debt | 3,153,466 | 3,080,726 |
Current liabilities | ||
Notes payable | 357,215 | 145,000 |
Accounts payable | 143,681 | 131,988 |
Accrued interest | 18,776 | 18,854 |
Accrued taxes other than income | 41,324 | 42,571 |
Accrued liabilities | 30,058 | 22,931 |
Customer deposits | 60,811 | 61,209 |
Other current liabilities | 21,465 | 21,380 |
Total current liabilities | 673,330 | 443,933 |
Deferred credits and other liabilities [Abstract] | ||
Deferred income taxes | 599,945 | 1,038,568 |
Regulatory Liability, Noncurrent | 519,421 | 0 |
Employee benefit obligations | 172,938 | 303,507 |
Other deferred credits | 87,778 | 76,057 |
Total deferred credits and other liabilities | 1,380,082 | 1,418,132 |
Commitments and contingencies | ||
Total liabilities and equity | $ 5,206,878 | $ 4,942,791 |
BALANCE SHEETS BALANCE SHEETS P
BALANCE SHEETS BALANCE SHEETS Parenthetical - USD ($) $ in Thousands | Dec. 31, 2017 | Dec. 31, 2016 |
Common Stock, Par or Stated Value Per Share | $ 0.01 | $ 0.01 |
Common Stock, Shares Authorized | 250,000,000 | 250,000,000 |
Common Stock, Shares, Issued | 52,598,005 | 52,598,005 |
Common Stock, Shares, Outstanding | 52,312,516 | 52,283,260 |
Treasury Stock, Shares | 285,489 | 314,745 |
Debt issuance costs | $ 8,033 | $ 8,851 |
STATEMENTS OF CASH FLOWS
STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Operating activities | |||
Net income | $ 162,995 | $ 140,095 | $ 119,030 |
Adjustments to reconcile net income to net cash provided by operating activities: | |||
Depreciation and amortization | 151,889 | 143,829 | 133,023 |
Deferred income taxes | 92,393 | 86,788 | 63,789 |
Share-based compensation expense | 8,876 | 11,219 | 9,187 |
Provision for doubtful accounts | 7,323 | 5,427 | 4,520 |
Changes in assets and liabilities: | |||
Accounts receivable | (15,147) | (80,028) | 105,886 |
Materials and supplies | (5,588) | (759) | (5,814) |
Income tax receivable | 0 | 37,480 | 4,923 |
Natural gas in storage | (4,722) | 16,721 | 43,147 |
Asset removal costs | (52,376) | (53,430) | (51,608) |
Accounts payable | 1,945 | 27,596 | (59,635) |
Accrued interest | (78) | (19) | 1 |
Accrued taxes other than income | (1,247) | 5,322 | (7,493) |
Accrued liabilities | 7,127 | (8,539) | 5,451 |
Customer deposits | (398) | 884 | 322 |
Regulatory assets and liabilities | 29,250 | (49,472) | 50,658 |
Employee benefit obligation | (118,095) | (25,666) | (15,033) |
Other assets and liabilities | (10,347) | 33,141 | 7,562 |
Cash provided by operating activities | 253,800 | 290,589 | 407,916 |
Investing activities | |||
Capital expenditures | (356,361) | (309,071) | (294,320) |
Other | 618 | 492 | 0 |
Cash used in investing activities | (355,743) | (308,579) | (294,320) |
Financing activities | |||
Borrowings (repayment) on notes payable, net | 212,215 | 132,500 | (29,500) |
Repurchase of common stock | (17,512) | (24,066) | (24,122) |
Issuance of common stock | 4,457 | 4,017 | 7,051 |
Dividends paid | (87,951) | (73,209) | (62,826) |
Tax withholdings related to net share settlements of stock compensation | (9,516) | (9,022) | (13,709) |
Cash provided by (used in) financing activities | 101,693 | 30,220 | (123,106) |
Change in cash and cash equivalents | (250) | 12,230 | (9,510) |
Cash and cash equivalents at beginning of period | 14,663 | 2,433 | 11,943 |
Cash and cash equivalents at end of period | 14,413 | 14,663 | 2,433 |
Supplemental cash flow information: | |||
Cash paid for interest, net of amounts capitalized | 44,436 | 42,129 | 42,980 |
Cash received for income taxes, net | $ (1,389) | $ (35,702) | $ (5,423) |
STATEMENT OF CHANGES IN EQUITY
STATEMENT OF CHANGES IN EQUITY - USD ($) $ in Thousands | Total | Retained Earnings [Member] | Accumulated Other Comprehensive Income (Loss) [Member] | Treasury Stock [Member] | Common Stock [Member] | Additional Paid-in Capital [Member] |
Common Stock, Dividends, Declared, Annualized Basis | $ 1.20 | |||||
Shares Issued, beginning balance at Dec. 31, 2014 | 52,083,859 | |||||
Equity, beginning balance at Dec. 31, 2014 | $ 1,794,037 | $ 39,894 | $ (5,174) | $ 0 | $ 521 | $ 1,758,796 |
Net income | 119,030 | 119,030 | 0 | 0 | 0 | 0 |
Other comprehensive loss | 773 | 0 | 773 | 0 | 0 | 0 |
Repurchase of common stock | (24,122) | 0 | 0 | (24,122) | $ 0 | 0 |
Common stock issued, shares | 514,146 | |||||
Common stock issued, value | 14,663 | 0 | 0 | 9,631 | $ 5 | 5,027 |
Common stock dividends | (62,826) | (63,878) | 0 | 0 | $ 0 | 1,052 |
Shares Issued, ending balance at Dec. 31, 2015 | 52,598,005 | |||||
Equity, ending balance at Dec. 31, 2015 | $ 1,841,555 | 95,046 | (4,401) | (14,491) | $ 526 | 1,764,875 |
Common Stock, Dividends, Declared, Annualized Basis | $ 1.40 | |||||
Net income | $ 140,095 | 140,095 | 0 | 0 | 0 | 0 |
Other comprehensive loss | (314) | 0 | (314) | 0 | 0 | 0 |
Repurchase of common stock | (24,066) | 0 | 0 | (24,066) | $ 0 | 0 |
Common stock issued, shares | 0 | |||||
Common stock issued, value | 4,219 | 0 | 0 | 20,431 | $ 0 | (16,212) |
Common stock dividends | (73,209) | (74,120) | 0 | 0 | $ 0 | 911 |
Shares Issued, ending balance at Dec. 31, 2016 | 52,598,005 | |||||
Equity, ending balance at Dec. 31, 2016 | 1,888,280 | 161,021 | (4,715) | (18,126) | $ 526 | 1,749,574 |
Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net | $ 10,982 | 10,982 | 0 | 0 | 0 | 0 |
Common Stock, Dividends, Declared, Annualized Basis | $ 1.68 | |||||
Net income | $ 162,995 | 162,995 | 0 | 0 | 0 | 0 |
Other comprehensive loss | (778) | 0 | (778) | 0 | 0 | 0 |
Repurchase of common stock | (17,512) | 0 | 0 | (17,512) | $ 0 | 0 |
Common stock issued, shares | 0 | |||||
Common stock issued, value | 4,193 | 0 | 0 | 17,142 | $ 0 | (12,949) |
Common stock dividends | (87,951) | (88,877) | 0 | 0 | $ 0 | 926 |
Shares Issued, ending balance at Dec. 31, 2017 | 52,598,005 | |||||
Equity, ending balance at Dec. 31, 2017 | $ 1,960,209 | $ 246,121 | $ (5,493) | $ (18,496) | $ 526 | $ 1,737,551 |
SUMMARY OF SIGNIFICANT ACCOUNTI
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Notes) | 12 Months Ended |
Dec. 31, 2017 | |
Significant Accounting Policies [Line Items] | |
SIGNIFICANT ACCOUNTING POLICIES | 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Organization and Nature of Operations - We provide natural gas distribution services to more than 2 million customers through our divisions in Oklahoma, Kansas and Texas through Oklahoma Natural Gas, Kansas Gas Service and Texas Gas Service, respectively. We serve residential, commercial, industrial and transportation customers in all three states. In addition, we also provide natural gas distribution services to wholesale and public authority customers. We are a corporation incorporated under the laws of the state of Oklahoma, and our common stock is listed on the NYSE under the trading symbol “OGS.” In 2017, we formed a wholly-owned captive insurance company in the state of Oklahoma to provide insurance to our divisions. Basis of Presentation - The consolidated financial statements include the accounts of the natural gas distribution business as set forth in “Organization and Nature of Operations” above. All significant balances and transactions between our subsidiaries have been eliminated. Use of Estimates - The preparation of our consolidated financial statements and related disclosures in accordance with GAAP requires us to make estimates and assumptions with respect to values or conditions that cannot be known with certainty that affect the reported amount of assets and liabilities, and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements. These estimates and assumptions also affect the reported amounts of revenue and expenses during the reporting period. Items that may be estimated include, but are not limited to, the economic useful life of assets, fair value of assets and liabilities, provisions for doubtful accounts receivable, unbilled revenues for natural gas delivered but for which meters have not been read, natural gas purchased but for which no invoice has been received, provision for income taxes, including any deferred income tax valuation allowances, the results of litigation and various other recorded or disclosed amounts. We evaluate these estimates on an ongoing basis using historical experience and other methods we consider reasonable based on the particular circumstances. Nevertheless, actual results may differ significantly from the estimates. Any effects on our financial position or results of operations from revisions to these estimates are recorded in the period when the facts that give rise to the revision become known. Fair Value Measurements - We define fair value as the price that would be received from the sale of an asset or the transfer of a liability in an orderly transaction between market participants at the measurement date. We use the market and income approaches to determine the fair value of our assets and liabilities and consider the markets in which the transactions are executed. We measure the fair value of a group of financial assets and liabilities consistent with how a market participant would price the net risk exposure at the measurement date. Fair Value Hierarchy - At each balance sheet date, we utilize a fair value hierarchy to classify fair value amounts recognized or disclosed in our consolidated financial statements based on the observability of inputs used to estimate such fair value. The levels of the hierarchy are described below: • Level 1 - Unadjusted quoted prices in active markets for identical assets or liabilities; • Level 2 - Significant observable pricing inputs other than quoted prices included within Level 1 that are, either directly or indirectly, observable as of the reporting date. Essentially, this represents inputs that are derived principally from or corroborated by observable market data; and • Level 3 - May include one or more unobservable inputs that are significant in establishing a fair value estimate. These unobservable inputs are developed based on the best information available and may include our own internal data. We recognize transfers into and out of the levels as of the end of each reporting period. Determining the appropriate classification of our fair value measurements within the fair value hierarchy requires management’s judgment regarding the degree to which market data is observable or corroborated by observable market data. We categorize derivatives for which fair value is determined using multiple inputs within a single level, based on the lowest level input that is significant to the fair value measurement in its entirety. See Note 7 for additional information regarding our fair value measurements. Cash and Cash Equivalents - Cash equivalents consist of highly liquid investments, which are readily convertible into cash and have original maturities of three months or less. Revenue Recognition - For regulated deliveries of natural gas, we read meters and bill customers on a monthly cycle. We recognize revenues upon the delivery of the natural gas commodity or services rendered to customers. The billing cycles for customers do not necessarily coincide with the accounting periods used for financial reporting purposes. Revenues are accrued for natural gas delivered and services rendered to customers, but not yet billed. Accrued unbilled revenue is based on a percentage estimate of amounts unbilled each month, which is dependent upon a number of factors, some of which require management’s judgment. These factors include customer consumption patterns and the impact of weather on usage. The amounts of accrued unbilled natural gas sales revenues at December 31, 2017 and 2016 , were $138.5 million and $143.2 million , respectively. We collect and remit other taxes on behalf of governmental authorities, and we record these amounts in accrued taxes other than income in our Consolidated Balance Sheets on a net basis. Cost of Natural Gas - Net margin is comprised of total revenues less cost of natural gas. Cost of natural gas includes commodity purchases, fuel, storage, transportation and other gas purchase costs recovered through our cost of natural gas regulatory mechanisms and does not include an allocation of general operating costs or depreciation and amortization. In addition, our cost of natural gas regulatory mechanisms provide a method of recovering natural gas costs on an ongoing basis without a profit. Therefore, although our revenues will fluctuate with the cost of gas that we purchase, net margin is not affected by fluctuations in the cost of natural gas. See Note 8 for additional discussion of purchased gas cost recoveries. Accounts Receivable - Accounts receivable represent valid claims against nonaffiliated customers for natural gas sold or services rendered, net of allowances for doubtful accounts. We assess the creditworthiness of our customers. Those customers who do not meet minimum standards are required to provide security, including deposits and other forms of collateral, when appropriate. With more than 2 million customers across three states, we are not exposed materially to a concentration of credit risk. We maintain an allowance for doubtful accounts based upon factors surrounding the credit risk of customers, historical trends, consideration of the current credit environment and other information. In Oklahoma, Kansas and most jurisdictions we serve in Texas, we are able to recover natural gas costs related to doubtful accounts through purchased-gas cost adjustment mechanisms. At December 31, 2017 and 2016 , our allowance for doubtful accounts was $4.8 million and $4.2 million , respectively. Inventories - Natural gas in storage is maintained on the basis of weighted-average cost. Natural gas inventories that are injected into storage are recorded in inventory based on actual purchase costs, including storage and transportation costs. Natural gas inventories that are withdrawn from storage are accounted for in our purchased-gas cost adjustment mechanisms at the weighted-average inventory cost. Materials and supplies inventories are stated at the lower of weighted-average cost or net realizable value. Derivatives and Risk Management Activities - We record all derivative instruments at fair value, with the exception of normal purchases and normal sales that are expected to result in physical delivery. The accounting for changes in the fair value of a derivative instrument depends on whether it has been designated and qualifies as part of a hedging relationship and, if so, the reason for holding it, or if regulatory rulings require a different accounting treatment. If certain conditions are met, we may elect to designate a derivative instrument as a hedge of exposure to changes in fair values or cash flows. The table below summarizes the various ways in which we account for our derivative instruments and the impact on our consolidated financial statements: Recognition and Measurement Accounting Treatment Balance Sheet Income Statement Normal purchases and normal sales - Fair value not recorded - Change in fair value not recognized in earnings Mark-to-market - Recorded at fair value - Change in fair value recognized in, and recoverable through, the purchased-gas cost adjustment mechanisms We have not elected to formally designate any of our derivative instruments as hedges. Gains or losses associated with the fair value of commodity derivative instruments entered into by us are included in, and recoverable through, the purchased-gas cost adjustment mechanisms. See Note 7 for additional information regarding our fair value measurements and hedging activities using derivatives. Property, Plant and Equipment - Our properties are stated at cost, which includes direct construction costs such as direct labor, materials, burden and AFUDC. Generally, the cost of our property retired or sold, plus removal costs, less salvage, is charged to accumulated depreciation. Gains and losses from sales or retirement of an entire operating unit or system of our properties are recognized in income. Maintenance and repairs are charged directly to expense. AFUDC represents the cost of borrowed funds used to finance construction activities. We capitalize interest costs during the construction or upgrade of qualifying assets. Capitalized interest is recorded as a reduction to interest expense. Our properties are depreciated using the straight-line method over their estimated useful lives. Generally, we apply composite depreciation rates to functional groups of property having similar economic circumstances. We periodically conduct depreciation studies to assess the economic lives of our assets. These depreciation studies are completed as a part of our regulatory proceedings, and the changes in economic lives, if applicable, are implemented prospectively when the new rates are approved by our regulators and become effective. Changes in the estimated economic lives of our property, plant and equipment could have a material effect on our financial position, results of operations or cash flows. Property, plant and equipment on our Consolidated Balance Sheets includes construction work in process for capital projects that have not yet been placed in service and therefore are not being depreciated. Assets are transferred out of construction work in process when they are substantially complete and ready for their intended use. See Note 9 for additional information regarding our property, plant and equipment. Impairment of Goodwill and Long-Lived Assets - We assess our goodwill for impairment at least annually as of July 1. Our goodwill impairment analysis performed in 2017, 2016 and 2015 , utilized a qualitative assessment and did not result in any impairment indicators. Subsequent to July 1, 2017 , no event has occurred indicating that it is more likely than not that our fair value is less than our carrying value of our net assets. As part of our goodwill impairment test, we first assess qualitative factors (including macroeconomic conditions, industry and market considerations, cost factors and overall financial performance) to determine whether it is more likely than not that our fair value is less than our carrying amount. If further testing is necessary, we perform an impairment test for goodwill. This assessment is made by comparing our fair value with our book value, including goodwill. If the fair value is less than the book value, we will record an impairment charge, not to exceed the carrying amount of goodwill. To estimate our fair value, we use two generally accepted valuation approaches, an income approach and a market approach, using assumptions consistent with a market participant’s perspective. Under the income approach, we use anticipated cash flows over a period of years plus a terminal value and discount these amounts to their present value using appropriate discount rates. Under the market approach, we apply acquisition multiples to forecasted cash flows. The acquisition multiples used are consistent with historical market transactions. The forecasted cash flows are based on average forecasted cash flows over a period of years. We assess our long-lived assets for impairment whenever events or changes in circumstances indicate that an asset’s carrying amount may not be recoverable. An impairment is indicated if the carrying amount of a long-lived asset exceeds the sum of the undiscounted future cash flows expected to result from the use and eventual disposition of the asset. If an impairment is indicated, we record an impairment loss equal to the difference between the carrying value and the fair value of the long-lived asset. We determined that there were no asset impairments in 2017, 2016 or 2015 . Regulation - We are subject to the rate regulation and accounting requirements of the OCC, KCC, RRC and various municipalities in Texas. We follow the accounting and reporting guidance for regulated operations. During the ratemaking process, regulatory authorities set the framework for what we can charge customers for our services and establish the manner that our costs are accounted for, including allowing us to defer recognition of certain costs and permitting recovery of the amounts through rates over time, as opposed to expensing such costs as incurred. Examples include weather normalization, unrecovered purchased-gas costs, pension and postemployment benefit costs and ad-valorem taxes. This allows us to stabilize rates over time rather than passing such costs on to the customer for immediate recovery. Actions by regulatory authorities could have an effect on the amount recovered from rate payers. Any difference in the amount recoverable and the amount deferred is recorded as income or expense at the time of the regulatory action. A write-off of regulatory assets and costs not recovered may be required if all or a portion of the regulated operations have rates that are no longer: • established by independent regulators; • designed to recover the specific entity’s costs of providing regulated services; and • set at levels that will recover our costs when considering the demand and competition for our services. See Note 8 for additional information regarding our regulatory assets and liabilities disclosures. Pension and Other Postemployment Employee Benefits - We have defined benefit retirement plans covering eligible employees. We also sponsor welfare plans that provide other postemployment medical and life insurance benefits to eligible employees who retire with at least five years of service. To calculate the costs and liabilities related to our plans, we utilize an outside actuarial consultant, which uses statistical and other factors to anticipate future events. These factors include assumptions about the discount rate, expected return on plan assets, rate of future compensation increases, age and mortality and employment periods. We use tables issued by the Society of Actuaries to estimate mortality rates. In determining the projected benefit obligations and costs, assumptions can change from period to period and may result in material changes in the cost and liabilities we recognize. Income Taxes - Deferred income taxes are recorded for the difference between the financial statement and income tax basis of assets and liabilities and carryforward items, based on income tax laws and rates existing at the time the temporary differences are expected to reverse. The effect on deferred income taxes of a change in tax rates is deferred and amortized for operations regulated by the OCC, KCC, RRC and various municipalities in Texas, if, as a result of an action by a regulator, it is probable that the effect of the change in tax rates will be recovered from or returned to customers through future rates. We continue to amortize previously deferred investment tax credits for ratemaking purposes over the periods prescribed by our regulators. A valuation allowance for deferred income tax assets is recognized when it is more likely than not that some or all of the benefit from the deferred income tax asset will not be realized. To assess that likelihood, we use estimates and judgment regarding our future taxable income, as well as the jurisdiction in which such taxable income is generated, to determine whether a valuation allowance is required. Such evidence can include our current financial position, our results of operations, both actual and forecasted, the reversal of deferred income tax liabilities, as well as the current and forecasted business economics of our industry. We had no valuation allowance at December 31, 2017 and 2016 . We utilize a more-likely-than-not recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position that is taken or expected to be taken in a tax return. We reflect penalties and interest as part of income tax expense as they become applicable for tax provisions that do not meet the more-likely-than-not recognition threshold and measurement attribute. There were no material uncertain tax positions at December 31, 2017 and 2016 . See Note 12 for additional information regarding income taxes. Asset Retirement Obligations - Asset retirement obligations represent legal obligations associated with the retirement of long-lived assets that result from the acquisition, construction, development and/or normal use of the asset. Certain long-lived assets that comprise our natural gas distribution systems, primarily our pipeline assets, are subject to agreements or regulations that give rise to an asset retirement obligation for removal or other disposition costs associated with retiring the assets in place upon the discontinued use of the natural gas distribution system. We recognize the fair value of a liability for an asset retirement obligation in the period when it is incurred if a reasonable estimate of the fair value can be made. We are not able to estimate reasonably the fair value of the asset retirement obligations for portions of our assets because the settlement dates are indeterminable given our expected continued use of the assets with proper maintenance. We expect our natural gas distribution systems will continue in operation as long as natural gas supply and demand for natural gas distribution service exists. Based on the widespread use of natural gas for heating and cooking activities by residential and commercial customers in our service areas, management expects supply and demand to exist for the foreseeable future. In accordance with long-standing regulatory treatment, we collect through rates the estimated costs of removal on certain regulated properties through depreciation expense, with a corresponding credit to accumulated depreciation and amortization. These removal costs collected through our rates include costs attributable to legal and nonlegal removal obligations; however, the amounts collected that are in excess of these nonlegal asset-removal costs incurred are accounted for as a regulatory liability for financial reporting purposes. Historically, with the exception of the regulatory authority in Kansas, the regulatory authorities that have jurisdiction over our regulated operations have not required us to quantify or disclose this amount; rather, these costs are addressed prospectively in depreciation rates and are set in each general rate order. We have made an estimate of our regulatory liability using current rates since the last general rate order in each of our jurisdictions if the removal costs collected have exceeded our removal cost incurred; however, for financial reporting purposes, significant uncertainty exists regarding the future disposition of this regulatory liability, pending, among other issues, clarification of regulatory intent. We continue to monitor the regulatory requirements, and the liability may be adjusted as more information is obtained. We record the estimated asset removal obligation in noncurrent liabilities in other deferred credits on our Consolidated Balance Sheets. To the extent this estimated liability is adjusted, such amounts will be reclassified between accumulated depreciation and amortization and other deferred credits and therefore will not have an impact on earnings. Contingencies - Our accounting for contingencies covers a variety of business activities, including contingencies for legal and environmental exposures. We accrue these contingencies when our assessments indicate that it is probable that a liability has been incurred or an asset will not be recovered and an amount can be estimated reasonably. We expense legal fees as incurred and base our legal liability estimates on currently available facts and our estimates of the ultimate outcome or resolution. Accruals for estimated losses from environmental remediation obligations generally are recognized no later than the completion of a remediation feasibility study. Recoveries of environmental remediation costs from other parties are recorded as assets when their receipt is deemed probable. Actual results may differ from our estimates resulting in an impact, positive or negative, on earnings. See Note 13 for additional information regarding contingencies. Share-Based Payments - We expense the fair value of share-based payments net of estimated forfeitures. We estimate forfeiture rates based on historical forfeitures under our share-based payment plans. Earnings per share - Basic EPS is based on net income and is calculated based upon the daily weighted-average number of common shares outstanding during the periods presented. Also, this calculation includes fully vested stock awards that have not yet been issued as common stock. Diluted EPS includes the above, plus unvested stock awards granted under our compensation plans, but only to the extent these instruments dilute earnings per share. Segments - We operate in one reportable business segment: regulated public utilities that deliver natural gas to residential, commercial, industrial, wholesale, public authority and transportation customers. We define reportable business segments as components of an organization for which discrete financial information is available and operating results are evaluated on a regular basis by the chief operating decision maker (“CODM”) in order to assess performance and allocate resources. Our CODM is our Chief Executive Officer (“CEO”). Characteristics of our organization that were relied upon in making this determination include the similar nature of services we provide, the functional alignment of our organizational structure, and the reports that are regularly reviewed by the CODM for the purpose of assessing performance and allocating resources. Our management is functionally aligned and centralized, with performance evaluated based upon results of the entire distribution business. Capital allocation decisions are driven by asset integrity management, operating efficiency, growth opportunities and government relocations, not geographic location or regulatory jurisdiction. In 2017 , 2016 and 2015 , we had no single external customer from which we received 10 percent or more of our gross revenues. Treasury Stock - We record treasury stock purchases at cost, which includes incremental direct transaction costs. Amounts are recorded as reductions in equity in our Consolidated Balance Sheets. We record the reissuance of treasury stock at our weighted average cost of treasury shares recorded in equity in our Consolidated Balance Sheets. Recently Issued Accounting Standards Update - In February 2018, the FASB issued ASU 2018-02, “Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income,’’ which allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017. This new guidance is required for our interim and annual reports for periods beginning after December 15, 2018, and early adoption is permitted. We are currently assessing the timing and impacts of adopting this standard, but do not expect a material impact to our consolidated financial statements. In August 2017, the FASB issued ASU 2017-12, “Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities,” which allows more types of hedging strategies to be eligible for hedge accounting and simplifies application of hedge accounting. This new guidance is required for our interim and annual reports for periods beginning after December 15, 2018, and early adoption is permitted, but must be applied as of the beginning of the fiscal year, or initial application date. The impact of this guidance is not material to us, as we have not elected hedge accounting due to the nature of the types of derivatives we have entered. In March 2017, the FASB issued ASU 2017-07, “Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost,” which requires (1) separation of net periodic service costs for pension and other postemployment benefits into service cost and other components, (2) presentation of the service cost component in the same line as other compensation costs rendered by pertinent employees during the period, and (3) reporting the other components of net periodic benefit costs separately from the service cost component and outside a subtotal of income from operations. Additionally, only the service cost component is eligible for capitalization for GAAP, when applicable. However, all of our cost components remain eligible for capitalization under the accounting requirements for rate regulated entities. We will adopt this guidance for our interim and annual reports in the first quarter of 2018. When adopted, the presentation changes required for net periodic benefit costs will not impact previously reported net income; however, the reclassification of the other components of benefits costs will result in an increase in operating income and an increase in other expenses for 2017 and 2016 of $17.3 million and $19.8 million , respectively. We will use the retroactive presentation that permits the use of the amounts disclosed for the various components of net benefit cost in our Employee Benefit Plans footnote to our consolidated financial statements as the basis for the retrospective application. In addition, we updated our information systems for the capitalization of service costs to property and non-service costs to a regulatory asset on a prospective basis, as well as the appropriate accounts for non-service costs to apply retroactive reclassification. In January 2017, the FASB issued ASU 2017-04, “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment,” which simplifies how an entity is required to test goodwill for impairment by eliminating Step 2 of the goodwill test, where the measurement of a goodwill impairment loss was determined by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. Upon adoption, a goodwill impairment will be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. We early adopted this new guidance in the current year, and it did not have an impact on our consolidated financial statements. See our conclusions regarding our current year Goodwill Impairment Test above. In June 2016, the FASB issued ASU 2016-13, “Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments,’’ which introduced new guidance to the accounting for credit losses on instruments within its scope, including trade receivables. It is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, and may be adopted a year earlier. The new guidance will be initially applied through a cumulative-effect adjustment to retained earnings as of the beginning of the period of adoption. We are currently assessing the timing and impacts of adopting this standard, which must be adopted by the first quarter of 2020. In March 2016, the FASB issued ASU 2016-09, “Improvements to Employee Share-Based Payment Accounting,” which includes various new aspects to simplify how share-based payments are accounted for and presented in the consolidated financial statements. The new standard modifies several aspects of the accounting and reporting for employee share-based payments and related tax accounting impacts, including the presentation in the consolidated statements of operations and cash flows. We adopted this new guidance in the first quarter 2017, and in accordance with the transition requirements, we recorded $5.2 million of excess tax benefit in income tax expense and have transitioned all provisions of this new guidance prospectively, other than our presentation of our withholding shares for tax-withholding purposes, which we accounted for retrospectively in the Financing Activities section of our Consolidated Statement of Cash Flows. We recorded a noncash cumulative-effect increase of $11.0 million to retained earnings, with an offset to a deferred income tax asset, as of the beginning of the reporting period in 2017, for excess tax benefits earned prior to January 1, 2017, that had not been recognized. We continue our use of the estimation method to account for share unit award forfeitures rather than actual forfeitures. The retrospective impact of our withholding shares for tax-withholding purposes to our Consolidated Statement of Cash Flows for the year ended December 31, 2016 , was a $9.0 million increase to net cash provided by operating activities and a $9.0 million decrease to net cash used in financing activities. The retrospective impact of our withholding shares for tax-withholding purposes to our Consolidated Statement of Cash Flows for the year ended December 31, 2015 , was a $13.7 million increase to net cash provided by operating activities and a $13.7 million decrease to net cash used in financing activities. In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842),” which prescribes recognizing lease assets and liabilities on the balance sheet and includes disclosure of key information about leasing arrangements. A modified retrospective transition approach is required for leases existing at the time of adoption. In January 2018, the FASB issued ASU 2018-01, “Leases (Topic 842),” as an amendment to address stakeholder concerns about the costs and complexity of complying with the transition provisions of the new lease requirements to provide an optional transition practical expedient to not evaluate under Topic 842 existing or expired land easements that were not previously accounted for as leases under the current leases guidance in Topic 840. We are continuing to evaluate our population of leases, analyzing lease agreements, and holding meetings with cross-functional teams to determine the potential impact of this accounting standard on our financial position and results of operations and the transition approach we will utilize. We will adopt this new guidance in the first quarter of 2019. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers” (“ASC 606”), which clarifies and converges the revenue recognition principles under GAAP and International Financial Reporting Standards. In July 2015, FASB delayed the effective date for one year. We have evaluated all of our sources of revenue to determine the potential effect on our financial position, results of operations, cash flows and the related accounting policies and business processes. We |
CREDIT FACILITY AND SHORT-TERM
CREDIT FACILITY AND SHORT-TERM NOTES PAYABLE (Notes) | 12 Months Ended |
Dec. 31, 2017 | |
Short-term Debt [Line Items] | |
Short-term Debt [Text Block] | 2. CREDIT FACILITY AND SHORT-TERM NOTES PAYABLE In October 2017, we amended and restated our revolving credit agreement. The ONE Gas Credit Agreement remains a $700 million revolving unsecured credit facility, and includes a $20 million letter of credit subfacility and a $60 million swingline subfacility. We will also be able to request an increase in commitments of up to an additional $500 million upon satisfaction of customary conditions, including receipt of commitments from either new lenders or increased commitments from existing lenders. The ONE Gas Credit Agreement expires in October 2022 , and is available to provide liquidity for working capital, capital expenditures, acquisitions and mergers, the issuance of letters of credit and for other general corporate purposes. The ONE Gas Credit Agreement contains certain financial, operational and legal covenants. Among other things, these covenants include maintaining ONE Gas’ total debt-to-capital ratio of no more than 70 percent at the end of any calendar quarter. The ONE Gas Credit Agreement also contains customary affirmative and negative covenants, including covenants relating to liens, indebtedness of subsidiaries, investments, changes in the nature of business, fundamental changes, transactions with affiliates, burdensome agreements, and use of proceeds. In the event of a breach of certain covenants by ONE Gas, amounts outstanding under the ONE Gas Credit Agreement may become due and payable immediately. At December 31, 2017 , our total debt-to-capital ratio was 44 percent and we were in compliance with all covenants under the ONE Gas Credit Agreement. The ONE Gas Credit Agreement contains provisions for an applicable margin rate and an annual facility fee, both of which adjust with changes in our credit rating. Based on our current credit ratings, borrowings, if any, will accrue interest at LIBOR plus 79.5 basis points, and the annual facility fee is 8 basis points. We have a commercial paper program under which we may issue unsecured commercial paper up to a maximum amount of $700 million to fund short-term borrowing needs. The maturities of the commercial paper notes may vary but may not exceed 270 days from the date of issue. The commercial paper notes are sold generally at par less a discount representing an interest factor. The ONE Gas Credit Agreement is available to repay the commercial paper notes, if necessary. Amounts outstanding under the commercial paper program reduce the borrowing capacity under the ONE Gas Credit Agreement. At December 31, 2017 , we had $357.2 million of commercial paper, $2.1 million in letters of credit issued under the ONE Gas Credit Agreement, with no borrowings and $340.7 million of remaining credit available under the ONE Gas Credit Agreement. The weighted-average interest rate on our commercial paper was 1.55 percent and 0.95 percent at December 31, 2017 and 2016 , respectively. |
LONG-TERM DEBT (Notes)
LONG-TERM DEBT (Notes) | 12 Months Ended |
Dec. 31, 2017 | |
Debt Instrument [Line Items] | |
Long-term Debt [Text Block] | 3. LONG-TERM DEBT We have senior notes consisting of $300 million of 2.07 percent senior notes due 2019 , $300 million of 3.61 percent senior notes due 2024 and $600 million of 4.658 percent senior notes due 2044 . The indenture governing our Senior Notes includes an event of default upon the acceleration of other indebtedness of $100 million or more. Such events of default would entitle the trustee or the holders of 25 percent in the aggregate principal amount of the outstanding Senior Notes to declare those senior notes immediately due and payable in full. We may redeem our Senior Notes at par, plus accrued and unpaid interest to the redemption date, starting one month, three months, and six months, respectively, before their maturity dates. Prior to these dates, we may redeem these Senior Notes, in whole or in part, at a redemption price equal to the principal amount, plus accrued and unpaid interest and a make-whole premium. The redemption price will never be less than 100 percent of the principal amount of the respective note plus accrued and unpaid interest to the redemption date. Our Senior Notes are senior unsecured obligations, ranking equally in right of payment with all of our existing and future unsecured senior indebtedness. |
EQUITY (Notes)
EQUITY (Notes) | 12 Months Ended |
Dec. 31, 2017 | |
Class of Stock [Line Items] | |
Stockholders' Equity Note Disclosure [Text Block] | 4. EQUITY Preferred Stock - At December 31, 2017 , we had 50 million , $0.01 par value, authorized shares of preferred stock available. We have not issued or established any classes or series of shares of preferred stock. Common Stock - At December 31, 2017 , we had approximately 197.7 million shares of authorized common stock available for issuance. Treasury Shares - We purchase treasury shares to be used to offset shares issued under our equity compensation plan and the ESPP. Our Board of Directors established an annual limit of $20 million of treasury stock purchases, exclusive of funds received through the dividend reinvestment and the ESPP. Stock purchases may be made in the open market or in private transactions at times, and in amounts that we deem appropriate. There is no guarantee as to the exact number of shares that we purchase, and we can terminate or limit the program at any time. Dividends Declared - In January 2018, we declared a dividend of $0.46 per share ( $1.84 per share on an annualized basis) for shareholders of record on February 23, 2018, payable March 9, 2018. |
ACCUMULATED OTHER COMPREHENSIVE
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Notes) | 12 Months Ended |
Dec. 31, 2017 | |
Accumulated Other Comprehensive Income (Loss) [Line Items] | |
Comprehensive Income (Loss) Note [Text Block] | 5. ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) The following table sets forth the balance in accumulated other comprehensive income (loss) for the period indicated: Accumulated Other Comprehensive Income (Loss) (Thousands of dollars) January 1, 2016 $ (4,401 ) Pension and other postemployment benefit plans obligations Other comprehensive income (loss) before reclassification, net of tax of $486 (776 ) Amounts reclassified from accumulated other comprehensive income (loss), net of tax of $(289) 462 Other comprehensive income (loss) (314 ) December 31, 2016 (4,715 ) Pension and other postemployment benefit plans obligations Other comprehensive income (loss) before reclassification, net of tax of $808 (1,293 ) Amounts reclassified from accumulated other comprehensive income (loss), net of tax of $(322) 515 Other comprehensive income (loss) (778 ) December 31, 2017 $ (5,493 ) The following table sets forth the effect of reclassifications from accumulated other comprehensive income (loss) on our Consolidated Statements of Income for the period indicated: Affected Line Item in the Details about Accumulated Other Comprehensive Income Year Ended December 31, Consolidated Statements of (Loss) Components 2017 2016 2015 Income ( Thousands of dollars ) Pension and other postemployment benefit plan obligations (a) Amortization of net loss $ 42,591 $ 40,912 $ 47,494 Amortization of unrecognized prior service cost (4,597 ) (3,316 ) (1,962 ) 37,994 37,596 45,532 Regulatory adjustments (b) (37,157 ) (36,845 ) (44,615 ) 837 751 917 Income before income taxes (322 ) (289 ) (353 ) Income tax expense Total reclassifications for the period $ 515 $ 462 $ 564 Net income (a) These components of accumulated other comprehensive income (loss) are included in the computation of net periodic benefit cost. See Note 11 for additional information regarding our net periodic benefit cost. (b) Regulatory adjustments represent pension and other postemployment benefit costs expected to be recovered through rates and are deferred as part of our regulatory assets. See Note 8 for additional information regarding our regulatory assets and liabilities. |
EARNINGS PER SHARE (Notes)
EARNINGS PER SHARE (Notes) | 12 Months Ended |
Dec. 31, 2017 | |
EARNINGS PER SHARE OF COMMON STOCK, BASIC AND DILUTED [Line Items] | |
Earnings Per Share [Text Block] | 6. EARNINGS PER SHARE The following tables set forth the computation of basic and diluted EPS from continuing operations for the periods indicated: Year Ended December 31, 2017 Income Shares Per Share Amount ( Thousands, except per share amounts ) Basic EPS Calculation Net income available for common stock $ 162,995 52,527 $ 3.10 Diluted EPS Calculation Effect of dilutive securities — 452 Net income available for common stock and common stock equivalents $ 162,995 52,979 $ 3.08 Year Ended December 31, 2016 Income Shares Per Share Amount ( Thousands, except per share amounts ) Basic EPS Calculation Net income available for common stock $ 140,095 52,453 $ 2.67 Diluted EPS Calculation Effect of dilutive securities — 510 Net income available for common stock and common stock equivalents $ 140,095 52,963 $ 2.65 Year Ended December 31, 2015 Income Shares Per Share Amount ( Thousands, except per share amounts ) Basic EPS Calculation Net income available for common stock $ 119,030 52,578 $ 2.26 Diluted EPS Calculation Effect of dilutive securities — 676 Net income available for common stock and common stock equivalents $ 119,030 53,254 $ 2.24 |
DERIVATIVE FINANCIAL INSTRUMENT
DERIVATIVE FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS (Notes) | 12 Months Ended |
Dec. 31, 2017 | |
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items] | |
Fair Value Disclosures | 7. DERIVATIVE FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS Derivative Instruments - At December 31, 2017 , we held purchased natural gas call options for the heating season ending March 2018, with total notional amounts of 14.1 Bcf, for which we paid premiums of $5.5 million , and which had a fair value of $1.1 million . At December 31, 2016 , we held purchased natural gas call options for the heating season ended March 2017 , with total notional amounts of 14.3 Bcf, for which we paid premiums of $5.4 million , and which had a fair value of $6.5 million . The premiums paid and any cash settlements received are recorded as part of our unrecovered purchased-gas costs in current regulatory assets as these contracts are included in, and recoverable through, the purchased-gas cost adjustment mechanisms. Additionally, changes in fair value associated with these contracts are deferred as part of our unrecovered purchased-gas costs in our Consolidated Balance Sheets. Our natural gas call options are classified as Level 1 as fair value amounts are based on unadjusted quoted prices in active markets including NYMEX-settled prices. There were no transfers between levels for the periods presented. Other Financial Instruments - The approximate fair value of cash and cash equivalents, accounts receivable and accounts payable is equal to book value, due to the short-term nature of these items. Our cash and cash equivalents are comprised of bank and money market accounts, and are classified as Level 1. Short-term notes payable and commercial paper are due upon demand and, therefore, the carrying amounts approximate fair value and are classified as Level 1. The book value of our long-term debt, including current maturities, was $1.2 billion at both December 31, 2017 and 2016 . The estimated fair value of our long-term debt, including current maturities, was $1.3 billion and $1.2 billion at December 31, 2017 and 2016 , respectively. The estimated fair value of our Senior Notes was determined using quoted market prices, and are considered Level 2. |
REGULATORY ASSETS AND LIABILITI
REGULATORY ASSETS AND LIABILITIES (Notes) | 12 Months Ended |
Dec. 31, 2017 | |
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items] | |
Schedule of Regulatory Assets and Liabilities | 8. REGULATORY ASSETS AND LIABILITIES The table below presents a summary of regulatory assets, net of amortization, and liabilities for the periods indicated: December 31, 2017 Remaining Recovery Period Current Noncurrent Total ( Thousands of dollars ) Under-recovered purchased-gas costs 1 year $ 41,238 $ — $ 41,238 Pension and other postemployment benefit costs See Note 11 25,156 387,582 412,738 Weather normalization 1 year 17,461 — 17,461 Reacquired debt costs 10 years 812 7,298 8,110 MGP remediation costs 15 years — 6,104 6,104 Other 1 to 21 years 3,513 4,205 7,718 Total regulatory assets, net of amortization 88,180 405,189 493,369 Federal income tax rate changes (a) See Note 12 — (519,421 ) (519,421 ) Over-recovered purchased-gas costs 1 year (9,434 ) — (9,434 ) Ad-valorem tax 1 year (4 ) — (4 ) Total regulatory liabilities (9,438 ) (519,421 ) (528,859 ) Net regulatory assets and liabilities $ 78,742 $ (114,232 ) $ (35,490 ) (a) See Note 12 for additional information regarding our federal income tax rate changes regulatory liabilities. December 31, 2016 Remaining Recovery Period Current Noncurrent Total ( Thousands of dollars ) Under-recovered purchased-gas costs 1 year $ 29,901 $ — $ 29,901 Pension and other postemployment benefit costs See Note 11 31,498 427,448 458,946 Weather normalization 1 year 17,661 — 17,661 Reacquired debt costs 11 years 812 8,108 8,920 Other 1 to 22 years 3,274 4,966 8,240 Total regulatory assets, net of amortization 83,146 440,522 523,668 Over-recovered purchased-gas costs 1 year (10,154 ) — (10,154 ) Ad-valorem tax 1 year (1,768 ) — (1,768 ) Total regulatory liabilities (11,922 ) — (11,922 ) Net regulatory assets and liabilities $ 71,224 $ 440,522 $ 511,746 Regulatory assets on our Consolidated Balance Sheets, as authorized by the various regulatory authorities, are probable of recovery. Base rates are designed to provide a recovery of cost during the period rates are in effect but do not generally provide for a return on investment for amounts we have deferred as regulatory assets. All of our regulatory assets recoverable through base rates are subject to review by the respective regulatory authorities during future rate proceedings. We are not aware of any evidence that these costs will not be recoverable through either rate riders or base rates, and we believe that we will be able to recover such costs, consistent with our historical recoveries. Purchased-gas costs represent the natural gas costs that have been over- or under-recovered from customers through the purchased-gas cost adjustment mechanisms, and includes natural gas utilized in our operations and premiums paid and any cash settlements received from our purchased natural gas call options. We amortize reacquired debt costs in accordance with the accounting guidelines prescribed by the OCC and KCC. Weather normalization represents revenue over- or under-recovered through the WNA rider in Kansas. This amount is deferred as a regulatory asset or liability for a 12-month period. Kansas Gas Service then applies an adjustment to the customers’ bills for 12 months to refund the over-collected revenue or bill the under-collected revenue. Ad-valorem tax represents an increase or decrease in Kansas Gas Service’s taxes above or below the amount approved in a rate case. This amount is deferred as a regulatory asset or liability for a 12-month period. Kansas Gas Service then applies an adjustment to the customers’ bills for 12 months to refund the over-collected revenue or bill the under-collected revenue. Recovery through rates resulted in amortization of regulatory assets of approximately $1.0 million , $3.8 million and $1.6 million for the years ended December 31, 2017, 2016 and 2015 , respectively. We collect, through our rates, the estimated costs of removal on certain regulated properties through depreciation expense, with a corresponding credit to accumulated depreciation and amortization. These removal costs are nonlegal obligations; however, the amounts collected that are in excess of these nonlegal asset-removal costs incurred are accounted for as a regulatory liability. We have made an estimate of our regulatory liability using current rates since the last general rate order in each of our jurisdictions if the removal costs collected have exceeded our removal costs incurred. We record the estimated nonlegal asset-removal obligation in noncurrent liabilities in other deferred credits on our Consolidated Balance Sheets. In 2017, we recorded a regulatory asset of approximately $5.9 million for estimated costs expected to be incurred at, and nearby, our 12 former MGP sites which we own or retain responsibility for certain environmental conditions. In January 2016, as a result of our rate case in Oklahoma, we recorded a regulatory asset of $2.4 million to recover certain information technology costs incurred as a result of our separation from ONEOK in 2014, which will be recovered over four years. |
PROPERTY, PLANT AND EQUIPMENT (
PROPERTY, PLANT AND EQUIPMENT (Notes) | 12 Months Ended |
Dec. 31, 2017 | |
Property, Plant and Equipment [Line Items] | |
PROPERTY, PLANT AND EQUIPMENT | 9. PROPERTY, PLANT AND EQUIPMENT The following table sets forth our property, plant and equipment by property type, for the periods indicated: December 31, December 31, 2017 2016 ( Thousands of dollars ) Natural gas distribution pipelines and related equipment $ 4,572,343 $ 4,321,429 Natural gas transmission pipelines and related equipment 497,791 481,953 General plant and other 513,445 530,459 Construction work in process 130,333 70,327 Property, plant and equipment 5,713,912 5,404,168 Accumulated depreciation and amortization (1,706,327 ) (1,672,548 ) Net property, plant and equipment $ 4,007,585 $ 3,731,620 We compute depreciation expense by applying composite, straight-line rates of 2.0 percent to 3.0 percent that were approved by various regulatory authorities. We recorded capitalized interest of $3.0 million , $3.6 million and $2.6 million for the years ended December 31, 2017, 2016 and 2015 , respectively. We incurred liabilities for construction work in process and asset removal costs that had not been paid at December 31, 2017, 2016 and 2015 of $21.7 million , $11.9 million and $15.0 million , respectively. Such amounts are not included in capital expenditures on our Consolidated Statements of Cash Flows. |
SHARE-BASED PAYMENTS (Notes)
SHARE-BASED PAYMENTS (Notes) | 12 Months Ended |
Dec. 31, 2017 | |
Share-based Payments [Line Items] | |
Disclosure of Compensation Related Costs, Share-based Payments | 10. SHARE-BASED PAYMENTS The ECP provides for the granting of stock-based compensation, including incentive stock options, nonstatutory stock options, stock bonus awards, restricted stock awards, restricted stock unit awards, performance stock awards and performance unit awards to eligible employees and the granting of stock awards to nonemployee directors. We have reserved 2.8 million shares of common stock for issuance under the ECP. At December 31, 2017 , we had approximately 0.5 million shares available for issuance under the ECP, which reflect shares issued and estimated shares expected to be issued upon vesting of outstanding awards granted under the plan, less forfeitures. The plan allows for the deferral of awards granted in stock or cash, in accordance with Internal Revenue Code section 409A requirements. Compensation cost expensed for our share-based payment plans was $4.9 million , net of tax benefits of $3.0 million , for 2017 , $7.0 million , net of tax benefits of $4.3 million , for 2016 , and $5.7 million , net of tax benefits of $3.5 million , for 2015 . Restricted Stock Unit Awards - We have granted restricted stock unit awards to key employees that vest over a service period of generally three years and entitle the grantee to receive shares of our common stock. Restricted stock unit awards granted accrue dividend equivalents in the form of additional restricted stock units prior to vesting. Restricted stock unit awards are measured at fair value as if they were vested and issued on the grant date, reduced by expected dividend payments for awards that do not accrue dividends and adjusted for estimated forfeitures. Compensation expense is recognized on a straight-line basis over the vesting period of the award. A forfeiture rate of 3 percent per year based on historical forfeitures under our share-based payment plans is used. Performance Stock Unit Awards - We have granted performance stock unit awards to key employees. The shares of common stock underlying the performance stock units vest at the expiration of a service period of generally three years if certain performance criteria are met by us as determined by the Executive Compensation Committee of the Board of Directors. Upon vesting, a holder of performance stock units is entitled to receive a number of shares of common stock equal to a percentage (0 percent to 200 percent) of the performance stock units granted, based on our total shareholder return over the vesting period, compared with the total shareholder return of a peer group of other utilities over the same period. If paid, the outstanding performance stock unit awards entitle the grantee to receive shares of our common stock. The outstanding performance stock unit awards are equity awards with a market-based condition, which results in the compensation expense for these awards being recognized on a straight-line basis over the requisite service period, provided that the requisite service period is fulfilled, regardless of when, if ever, the market condition is satisfied. The performance stock unit awards granted accrue dividend equivalents in the form of additional performance stock units prior to vesting. The fair value of these performance stock units was estimated on the grant date based on a Monte Carlo model. The compensation expense on these awards will only be adjusted for changes in forfeitures. A forfeiture rate of 3 percent per year based on historical forfeitures under our share-based payment plans was used. Restricted Stock Unit Award Activity As of December 31, 2017 , there was $2.6 million of total unrecognized compensation costs related to the nonvested restricted stock unit awards, which is expected to be recognized over a weighted-average period of 1.7 years. The following tables set forth activity and various statistics for restricted stock unit awards outstanding under the respective plans for the period indicated: Number of Units Weighted- Average Price Nonvested at December 31, 2016 194,900 $ 41.68 Granted 37,825 $ 63.97 Vested (85,490 ) $ 33.76 Forfeited (6,570 ) $ 52.65 Nonvested at December 31, 2017 140,665 $ 51.97 2017 2016 2015 Weighted-average grant date fair value (per share) $ 63.97 $ 58.30 $ 41.40 Fair value of shares granted (thousands of dollars) $ 2,420 $ 2,503 $ 3,141 The fair value of restricted stock vested was $5.5 million and $4.5 million in 2017 and 2016 , respectively. Performance Stock Unit Award Activity As of December 31, 2017 , there was $5.1 million of total unrecognized compensation cost related to the nonvested performance stock unit awards, which is expected to be recognized over a weighted-average period of 1.7 years. The following tables set forth activity and various statistics related to our performance stock unit awards and the assumptions used by us in the valuations of the 2017, 2016 and 2015 grants at the grant date: Number of Units Weighted- Average Price Nonvested at December 31, 2016 288,811 $ 46.06 Granted 74,120 $ 68.94 Vested (117,626 ) $ 35.98 Forfeited (7,981 ) $ 58.58 Nonvested at December 31, 2017 237,324 $ 57.78 2017 2016 2015 Volatility (a) 20.70% 18.20% 15.90% Dividend yield 2.63% 2.40% 2.90% Risk-free interest rate 1.48% 0.91% 1.10% (a) - Volatility based on historical volatility over three years using daily stock price observations of our peer utilities. 2017 2016 2015 Weighted-average grant date fair value (per share) $ 68.94 $ 64.06 $ 44.48 Fair value of shares granted (thousands of dollars) $ 5,110 $ 4,766 $ 4,486 The fair value of performance stock vested was $15.6 million and $19.5 million in 2017 and 2016 , respectively. Employee Stock Purchase Plan We have reserved a total of 700 thousand shares of common stock for issuance under our ESPP. Subject to certain exclusions, all employees who work more than 20 hours per week are eligible to participate in the ESPP. Employees can choose to have up to 10 percent of their annual base pay withheld to purchase our common stock, subject to terms and limitations of the plan. The purchase price of the stock is 85 percent of the lower of the average market price of our common stock on the grant date or exercise date. Approximately 43 percent , 41 percent and 40 percent of employees participated in the plan in 2017, 2016 and 2015 , respectively, and purchased 78,472 shares at $56.80 in 2017 , 83,431 shares at $54.51 in 2016 , and 51,092 shares at $36.15 in 2015 . Compensation expense, before taxes, was $1.2 million , $1.4 million and $1.3 million in 2017, 2016 and 2015 , respectively. Employee Stock Award Program Under the Employee Stock Award Program, we issued, for no monetary consideration, one share of our common stock to all eligible employees when the per-share closing price of our common stock on the NYSE closed for the first time at or above each $1.00 increment above $34. The total number of shares of our common stock authorized for issuance under this program was 125,000 . Shares issued to employees under this program during 2017, 2016 and 2015 totaled 13,791 , 50,573 and 23,506 , respectively, leaving 1,812 shares remaining. Compensation expense, before taxes, related to the Employee Stock Award Program was $0.9 million , $3.0 million and $1.1 million for 2017, 2016 and 2015 , respectively. The Employee Stock Award Program will not be renewed. |
EMPLOYEE BENEFIT PLANS (Notes)
EMPLOYEE BENEFIT PLANS (Notes) | 12 Months Ended |
Dec. 31, 2017 | |
Defined Benefit Plans and Other Postemployment Benefit Plans Table Text Block [Line Items] | |
Pension and Other Postemployment Benefits Disclosure [Text Block] | 11. EMPLOYEE BENEFIT PLANS Retirement and Other Postemployment Benefit Plans Retirement Plans - We have a defined benefit pension plan covering nonbargaining-unit employees hired before January 1, 2005, and certain bargaining-unit employees hired before December 15, 2011. Nonbargaining-unit employees hired after December 31, 2004; employees represented by Local No. 304 of the International Brotherhood of Electrical Workers (“IBEW”) hired on or after July 1, 2010; employees represented by the United Steelworkers hired on or after December 15, 2011; and employees who accepted a one-time opportunity to opt out of the defined benefit pension plan are covered by a profit-sharing plan. Certain employees of the Texas Gas Service division are entitled to benefits under a frozen cash-balance pension plan. In addition, we have a supplemental executive retirement plan for the benefit of certain officers. No new participants in the supplemental executive retirement plan have been approved since 2005, and it was formally closed to new participants as of January 1, 2014. We fund our defined benefit pension costs at a level needed to maintain or exceed the minimum funding levels required by the Employee Retirement Income Security Act of 1974, as amended, and the Pension Protection Act of 2006. Pension expense was $30.2 million , $32.0 million and $38.0 million in 2017, 2016 and 2015 , respectively. Other Postemployment Benefit Plans - We sponsor health and welfare plans that provide postemployment medical and life insurance benefits to certain employees who retire with at least five years of service. The postemployment medical plan is contributory based on hire date, age and years of service, with retiree contributions adjusted periodically, and contains other cost-sharing features such as deductibles and coinsurance. Other postemployment benefit expense was $1.7 million , $2.6 million and $5.0 million in 2017, 2016 and 2015 , respectively, prior to regulatory deferrals. Plan Amendments - In September 2016, due to uncertain market conditions with health insurance exchange providers, we elected not to move the eligible pre-65 participants in our postemployment medical plans to a healthcare exchange. As a result, we remeasured the respective plan assets and benefit obligations, effective September 30, 2016. In the fourth quarter of 2016, we further amended our other postemployment medical plan to allow certain participants access to reimbursable retirement accounts. The net impact of these plan amendments in 2016 was a $483 thousand increase in our other postemployment benefit plan obligation. Actuarial Assumptions - The following table sets forth the weighted-average assumptions used to determine benefit obligations for pension and postemployment benefits for the periods indicated: December 31, 2017 2016 Discount rate - pension plans 3.80% 4.30% Discount rate - other postemployment plans 3.70% 4.20% Compensation increase rate 3.25% - 3.35% 3.25% - 3.40% The following table sets forth the weighted-average assumptions used by us to determine the periodic benefit costs for the periods indicated: Years Ended December 31, 2017 2016 2015 Discount rate - pension plans 4.30% 4.75% 4.25%/4.75% (c) Discount rate - other postemployment plans 4.20% 4.75%/3.75% (a) 4.25%/4.75% (c) Expected long-term return on plan assets - pension plans 7.75% 7.75% 7.75% Expected long-term return on plan assets - other postemployment plans 7.60% 8.00%/7.75% (b) 7.75% Compensation increase rate 3.25% - 3.40% 3.35% - 3.40% 3.30% - 3.50% (a) Discount rate for the nine months ended September 30, 2016, and three months ended December 31, 2016, respectively. (b) Expected long-term return on plan assets for the nine months ended September 30, 2016, and three months ended December 31, 2016, respectively. (c) Discount rate for the nine months ended September 30, 2015, and three months ended December 31, 2015, respectively. We determine our overall expected long-term rate of return on plan assets, based on our review of historical returns and economic growth models. At December 31, 2017, we updated our assumed mortality rates to incorporate the new set of mortality tables issued by the Society of Actuaries in October 2017. We determine our discount rates annually. We estimate our discount rate based upon a comparison of the expected cash flows associated with our future payments under our defined benefit pension and other postemployment obligations to a hypothetical bond portfolio created using high-quality bonds that closely match expected cash flows. Bond portfolios are developed by selecting a bond for each of the next 60 years based on the maturity dates of the bonds. Bonds selected to be included in the portfolios are only those rated by Moody’s as AA- or better and exclude callable bonds, bonds with less than a minimum issue size, yield outliers and other filtering criteria to remove unsuitable bonds. Regulatory Treatment - The OCC, KCC and regulatory authorities in Texas have approved the recovery of pension costs and other postemployment benefits costs through rates for Oklahoma Natural Gas, Kansas Gas Service and Texas Gas Service, respectively. The costs recovered through rates are based on current funding requirements and the net periodic benefit cost for defined benefit pension and other postemployment costs. Differences, if any, between the expense and the amount recovered through rates would be reflected in earnings, net of authorized deferrals. We historically have recovered defined benefit pension and other postemployment benefit costs through rates. We believe it is probable that regulators will continue to include the net periodic pension and other postemployment benefit costs in our cost of service. Obligations and Funded Status - The following table sets forth our defined benefit pension and other postemployment benefit plans, benefit obligations and fair value of plan assets for the periods indicated: Pension Benefits Other Postemployment Benefits December 31, December 31, 2017 2016 2017 2016 Changes in Benefit Obligation (Thousands of dollars) Benefit obligation, beginning of period $ 966,531 $ 985,624 $ 243,548 $ 228,253 Service cost 12,176 12,055 2,509 2,675 Interest cost 40,453 45,550 9,890 10,235 Plan participants’ contributions — — 3,483 3,043 Actuarial loss (gain) 76,325 25,886 12,129 14,309 Benefits paid (55,107 ) (71,066 ) (16,690 ) (15,450 ) Plan amendment — — 171 483 Settlements (46,487 ) (31,518 ) — — Benefit obligation, end of period 993,891 966,531 255,040 243,548 Change in Plan Assets Fair value of plan assets, beginning of period 739,586 785,161 166,046 155,495 Actual return on plan assets 135,056 48,768 31,228 9,733 Employer contributions 111,936 12,441 6,159 13,225 Plan participants’ contributions — — 3,483 3,043 Benefits paid (55,107 ) (71,066 ) (16,690 ) (15,450 ) Settlements (46,667 ) (35,718 ) — — Fair value of assets, end of period 884,804 739,586 190,226 166,046 Balance at December 31 $ (109,087 ) $ (226,945 ) $ (64,814 ) $ (77,502 ) Current liabilities $ (963 ) $ (941 ) $ — $ — Noncurrent liabilities (108,124 ) (226,004 ) (64,814 ) (77,502 ) Balance at December 31 $ (109,087 ) $ (226,945 ) $ (64,814 ) $ (77,502 ) We made contributions to our pension plan of $111.9 million and $12.4 million during 2017 and 2016, respectively. During 2017 and 2016, we purchased group annuity contracts for approximately $46.7 million and $35.7 million , respectively, and transferred to a third-party insurance company liabilities of approximately $46.5 million and $31.5 million , respectively, related to certain participants in our defined benefit pension plan. Benefits paid includes $18.1 million of lump sum payments to certain terminated vested participants during 2016. The accumulated benefit obligation for our defined benefit pension plans was $936.7 million and $912.4 million at December 31, 2017 and 2016 , respectively. There are no plan assets expected to be withdrawn and returned to us in 2018 . Components of Net Periodic Benefit Cost - The following tables set forth the components of net periodic benefit cost for our defined benefit pension and other postemployment benefit plans for the period indicated: Pension Benefits Year Ended December 31, 2017 2016 2015 (Thousands of dollars) Components of net periodic benefit cost Service cost $ 12,176 $ 12,055 $ 13,660 Interest cost 40,453 45,550 43,542 Expected return on assets (58,496 ) (61,183 ) (61,769 ) Amortization of unrecognized prior service cost — — 266 Amortization of net loss 36,107 35,543 42,226 Settlements — — 27 Net periodic benefit cost $ 30,240 $ 31,965 $ 37,952 Other Postemployment Benefits Year Ended December 31, 2017 2016 2015 (Thousands of dollars) Components of net periodic benefit cost Service cost $ 2,509 $ 2,675 $ 3,257 Interest cost 9,890 10,235 10,628 Expected return on assets (12,590 ) (12,370 ) (11,892 ) Amortization of unrecognized prior service cost (4,597 ) (3,316 ) (2,228 ) Amortization of net loss 6,484 5,369 5,268 Net periodic benefit cost $ 1,696 $ 2,593 $ 5,033 Other Comprehensive Income (Loss) - The following table sets forth the amounts recognized in other comprehensive income (loss) related to our defined benefit pension benefits for the period indicated: Pension Benefits Year Ended December 31, 2017 2016 2015 (Thousands of dollars) Net gain (loss) arising during the period $ (2,101 ) $ (1,262 ) $ 339 Amortization of loss 837 751 917 Deferred income taxes 486 197 (483 ) Total recognized in other comprehensive income (loss) $ (778 ) $ (314 ) $ 773 There were no amounts recognized in other comprehensive income (loss) related to our other postemployment benefits for the periods presented. The tables below set forth the amounts in accumulated other comprehensive income (loss) that had not yet been recognized as components of net periodic benefit expense for the periods indicated: Pension Benefits December 31, 2017 2016 (Thousands of dollars) Prior service credit (cost) $ — $ — Accumulated loss (378,595 ) (414,757 ) Accumulated other comprehensive loss before regulatory assets (378,595 ) (414,757 ) Regulatory asset for regulated entities 369,647 407,073 Accumulated other comprehensive loss after regulatory assets (8,948 ) (7,684 ) Deferred income taxes 3,455 2,969 Accumulated other comprehensive loss, net of tax $ (5,493 ) $ (4,715 ) Other Postemployment Benefits December 31, 2017 2016 (Thousands of dollars) Prior service credit (cost) $ 5,442 $ 10,211 Accumulated loss (49,030 ) (62,084 ) Accumulated other comprehensive loss before regulatory assets (43,588 ) (51,873 ) Regulatory asset for regulated entities 43,588 51,873 Accumulated other comprehensive loss after regulatory assets — — Deferred income taxes — — Accumulated other comprehensive loss, net of tax $ — $ — The following table sets forth the amounts recognized in either accumulated comprehensive income (loss) or regulatory assets expected to be recognized as components of net periodic benefit expense in the next fiscal year: Pension Benefits Other Postemployment Benefits Amounts to be recognized in 2018 (Thousands of dollars) Prior service credit (cost) $ — $ (4,567 ) Actuarial net loss $ 39,913 $ 3,887 Health Care Cost Trend Rates - The following table sets forth the assumed health care cost-trend rates for the periods indicated: 2017 2016 Health care cost-trend rate assumed for next year 7.00% 7.25% Rate to which the cost-trend rate is assumed to decline (the ultimate trend rate) 5.00% 5.00% Year that the rate reaches the ultimate trend rate 2023 2022 Assumed health care cost-trend rates have a significant effect on the amounts reported for our health care plans. A one percentage point change in assumed health care cost-trend rates would have the following effects: One Percentage One Percentage Point Increase Point Decrease (Thousands of dollars) Effect on total of service and interest cost $ 239 $ (238 ) Effect on other postemployment benefit obligation $ 2,906 $ (3,006 ) Plan Assets - Our investment strategy is to invest plan assets in accordance with sound investment practices that emphasize long-term fundamentals. The goal of this strategy is to maximize investment returns while managing risk in order to meet the plan’s current and projected financial obligations. To achieve this strategy, we have established a liability-driven investment strategy to change the allocations as the plan reaches certain funded status. The plan’s investments include a diverse blend of various domestic and international equities, investment-grade debt securities which mirror the cash flows of our liability, insurance contracts and alternative investments. The current target allocation for the assets of our defined benefit pension plan is as follows: Investment-grade bonds 40.0 % U.S. large-cap equities 18.0 % Alternative investments 14.0 % Developed foreign large-cap equities 10.0 % Mid-cap equities 7.0 % Emerging markets equities 6.0 % Small-cap equities 5.0 % Total 100 % As part of our risk management for the plans, minimums and maximums have been set for each of the asset classes listed above. All investment managers for the plan are subject to certain restrictions on the securities they purchase and, with the exception of indexing purposes, are prohibited from owning our stock. The current target allocation for the assets of our other postemployment benefits plan is 30 percent fixed income securities and 70 percent equity securities. The following tables set forth our pension benefits and other postemployment benefits plan assets by fair value category as of the measurement date: Pension Benefits December 31, 2017 Asset Category Level 1 Level 2 Level 3 Total (Thousands of dollars) Investments: Equity securities (a) $ 301,911 $ 91,014 $ — $ 392,925 Government obligations — 74,596 — 74,596 Corporate obligations (b) — 260,907 — 260,907 Cash and money market funds (c) 21,139 20,787 — 41,926 Insurance contracts and group annuity contracts — — 35,158 35,158 Other investments (d) — 585 78,707 79,292 Total assets $ 323,050 $ 447,889 $ 113,865 $ 884,804 (a) - This category represents securities of the various market sectors from diverse industries. (b) - This category represents bonds from diverse industries. (c) - This category is primarily money market funds. (d) - This category represents alternative investments such as hedge funds and other financial instruments. Pension Benefits December 31, 2016 Asset Category Level 1 Level 2 Level 3 Total (Thousands of dollars) Investments: Equity securities (a) $ 371,655 $ 58,987 $ — $ 430,642 Government obligations — 47,445 — 47,445 Corporate obligations (b) — 129,036 — 129,036 Cash and money market funds (c) 13,786 16,114 — 29,900 Insurance contracts and group annuity contracts — — 45,140 45,140 Other investments (d) — 71 57,352 57,423 Total assets $ 385,441 $ 251,653 $ 102,492 $ 739,586 (a) - This category represents securities of the various market sectors from diverse industries. (b) - This category represents bonds from diverse industries. (c) - This category is primarily money market funds. (d) - This category represents alternative investments such as hedge funds and other financial instruments. Other Postemployment Benefits December 31, 2017 Asset Category Level 1 Level 2 Level 3 Total (Thousands of dollars) Investments: Equity securities (a) $ 63,180 $ 123 $ — $ 63,303 Government obligations — 101 — 101 Corporate obligations (b) — 25,905 — 25,905 Cash and money market funds (c) 4,512 28 — 4,540 Insurance contracts and group annuity contracts — 96,377 — 96,377 Total assets $ 67,692 $ 122,534 $ — $ 190,226 (a) - This category represents securities of the various market sectors from diverse industries. (b) - This category represents bonds from diverse industries. (c) - This category is primarily money market funds. Other Postemployment Benefits December 31, 2016 Asset Category Level 1 Level 2 Level 3 Total (Thousands of dollars) Investments: Equity securities (a) $ 39,817 $ 7,323 $ — $ 47,140 Government obligations — 75 — 75 Corporate obligations (b) — 19,948 — 19,948 Cash and money market funds (c) 74 16,989 — 17,063 Insurance contracts and group annuity contracts — 81,820 — 81,820 Total assets $ 39,891 $ 126,155 $ — $ 166,046 (a) - This category represents securities of the various market sectors from diverse industries. (b) - This category represents bonds from diverse industries. (c) - This category is primarily money market funds. The following table sets forth the reconciliation of Level 3 fair value measurements of our pension plans for the periods indicated: Pension Benefits Insurance Contracts Other Investments Total (Thousands of dollars) January 1, 2016 $ 56,465 $ 57,972 $ 114,437 Net realized and unrealized gains (losses) 4,518 (620 ) 3,898 Settlements (15,843 ) — (15,843 ) December 31, 2016 $ 45,140 $ 57,352 $ 102,492 Net realized and unrealized gains (losses) 2,569 5,055 7,624 Purchases — 16,300 16,300 Sales and settlements (12,551 ) — (12,551 ) December 31, 2017 $ 35,158 $ 78,707 $ 113,865 Contributions - During 2017 , we contributed $111.9 million to our defined benefit pension plans and we contributed $6.2 million to our other postemployment benefit plans. In 2018, we expect to contribute $1.0 million to our defined benefit pension plans and expect to contribute $3.0 million to our other postemployment benefit plans. Pension and Other Postemployment Benefit Payments - Benefit payments for our defined benefit pension and other postemployment benefit plans for the period ended December 31, 2017 were $55.1 million and $16.7 million , respectively. The following table sets forth the pension benefits and other postemployment benefits payments expected to be paid in 2018-2027: Pension Benefits Other Postemployment Benefits to be paid in: (Thousands of dollars) 2018 $ 50,875 $ 17,293 2019 $ 51,635 $ 17,383 2020 $ 52,518 $ 17,538 2021 $ 53,516 $ 17,485 2022 $ 54,289 $ 17,558 2023 through 2027 $ 286,188 $ 85,543 The expected benefits to be paid are based on the same assumptions used to measure our benefit obligation at December 31, 2017 , and include estimated future employee service. Other Employee Benefit Plans 401(k) Plan - We have a 401(k) Plan which covers all full-time employees, and employee contributions are discretionary. We match 100 percent of each participant’s eligible contribution up to 6 percent of eligible compensation, subject to certain limits. Our contributions made to the plan were $11.7 million , $10.8 million and $10.2 million in 2017, 2016 and 2015 , respectively. Profit Sharing Plan - We have a profit sharing plan for all employees who do not participate in our defined benefit pension plan. We plan to make a contribution to the profit sharing plan each quarter equal to 1 percent of each participant’s eligible compensation during the quarter. Additional discretionary employer contributions may be made at the end of each year. Employee contributions are not allowed under the plan. Our contributions made to the plan were $8.1 million , $6.0 million and $6.5 million in 2017, 2016 and 2015 , respectively. Employee Deferred Compensation Plan - Our Nonqualified Deferred Compensation Plan provides certain employees with the option to defer portions of their compensation and provides nonqualified deferred compensation benefits that are not available due to limitations on employer and employee contributions to qualified defined contribution plans under the federal tax laws. Contributions made to the plan were not material in 2017, 2016 and 2015 . |
INCOME TAXES (Notes)
INCOME TAXES (Notes) | 12 Months Ended |
Dec. 31, 2017 | |
Income tax [Line Items] | |
INCOME TAXES | 12. INCOME TAXES In December 2017, the Tax Cuts and Jobs Act of 2017 was signed into law. Substantially all of the provisions of the new law are effective for taxable years beginning after December 31, 2017. The new law includes significant changes to the Code, including amendments which significantly change the taxation of business entities and includes specific provisions related to regulated public utilities. The more significant changes that impact us include reductions in the corporate federal statutory income tax rate to 21 percent from 35 percent , and several technical provisions including, among others, the elimination of full expensing for tax purposes of certain property acquired after September 27, 2017, the continuation of certain rate normalization requirements for accelerated depreciation benefits and the general allowance for the continued deductibility of interest expense. Additionally, the new law limits the utilization of NOLs arising after December 31, 2017, to 80 percent of taxable income with an indefinite carryforward. The staff of the SEC has recognized the complexity of reflecting the impacts of the Tax Cuts and Jobs Act of 2017 and issued guidance in Staff Accounting Bulletin 118 (“SAB 118”) which clarifies accounting for income taxes under ASC 740 if information is not yet available or complete and provides for up to a one-year period in which to complete the required analyses and accounting. We have completed or made a reasonable estimate for the measurement and accounting of the effects of the Tax Cuts and Jobs Act of 2017, which have been reflected in our December 31, 2017, consolidated financial statements. We are still analyzing certain aspects of the Tax Cuts and Jobs Act of 2017, refining our calculations and expect additional guidance from the U.S. Department of the Treasury and the Internal Revenue Service. Any additional issued guidance or future actions of our regulators could potentially affect the final determination of the accounting effects arising from the implementation of the Tax Cuts and Jobs Act of 2017. The following table sets forth our provision for income taxes for the periods indicated: Years Ended December 31, 2017 2016 2015 ( Thousands of dollars ) Current income tax provision Federal $ — $ (2,016 ) $ 7,135 State 750 471 2,055 Total current income tax provision 750 (1,545 ) 9,190 Deferred income tax provision Federal 83,138 76,247 56,440 State 9,255 10,541 7,349 Total deferred income tax provision 92,393 86,788 63,789 Total provision for income taxes $ 93,143 $ 85,243 $ 72,979 The following table is a reconciliation of our income tax provision for the periods indicated: Years Ended December 31, 2017 2016 2015 ( Thousands of dollars ) Income before income taxes $ 256,138 $ 225,338 $ 192,009 Federal statutory income tax rate 35 % 35 % 35 % Provision for federal income taxes 89,648 78,868 67,203 State income taxes, net of federal tax benefit 6,503 7,158 6,114 Nonregulated deferred tax rate decrease 2,162 — — Tax benefit of employee share based compensation (5,162 ) — — Other, net (8 ) (783 ) (338 ) Total provision for income taxes $ 93,143 $ 85,243 $ 72,979 The following table sets forth the tax effects of temporary differences that gave rise to significant portions of the deferred tax assets and liabilities for the periods indicated: December 31, 2017 2016 ( Thousands of dollars ) Deferred tax assets Employee benefits and other accrued liabilities $ 40,277 $ 123,333 Regulatory adjustments for enacted tax rate changes 129,421 — Net operating loss 24,712 23,094 Other 2,984 5,716 Total deferred tax assets 197,394 152,143 Deferred tax liabilities Excess of tax over book depreciation 677,249 990,682 Purchased-gas cost adjustment 13,805 13,822 Other regulatory assets and liabilities, net 106,285 186,207 Total deferred tax liabilities 797,339 1,190,711 Net deferred tax liabilities $ 599,945 $ 1,038,568 As a result of the enactment of the Tax Cuts and Jobs Act of 2017, we remeasured our deferred income taxes based upon the new tax rate enacted in 2017. As a regulated entity, the change in deferred income taxes applicable to amounts previously recovered through rates is deferred as a regulatory liability. The effect on the net deferred income tax liability for the enacted decrease in the federal tax rate was $517.2 million , of which $519.4 million was recorded as a reduction to the deferred income tax liabilities and deferred as a regulatory liability for ratemaking purposes and offset by $2.2 million recorded as an increase in deferred income tax expense attributable to the remeasured deferred income taxes associated with certain expenses not currently recovered in our rates. These adjustments had no impact on our 2017 cash flows. Reductions in our ADIT balances to reflect the reduced corporate income tax rate of 21 percent will result in amounts previously collected from utility customers for these deferred income taxes to be refundable to such customers. The Tax Cuts and Jobs Act of 2017 retains the provisions of the Code that stipulate how these excess deferred income taxes are to be passed back to customers for certain accelerated tax depreciation benefits. Potential refunds of these and other deferred income taxes will be determined by our regulators. We are working with our regulators in each of the states that we operate to address the impact of the Tax Cuts and Jobs Act of 2017 on our rates. In each state, we have received or expect to receive accounting orders requiring us to establish a separate regulatory liability for the difference in taxes included in our rates that have been calculated based on a 35 percent statutory income tax rate and the new 21 percent statutory income tax rate beginning in January 2018. The establishment of this regulatory liability will result in a reduction to our revenues beginning in the first quarter of fiscal 2018. The amount, period and timing of the return of these liabilities to utility customers will be determined by our regulators in each of our jurisdictions. As of December 31, 2017, we have federal and state income tax NOL carryforwards of $96.9 million and $96.6 million , respectively, which will expire at various dates from 2025 through 2037. We believe that it is more likely than not that the tax benefits of the NOL carryforwards will be utilized prior to their expirations; therefore, no valuation allowance is necessary. We have filed our consolidated federal and state tax returns for years 2014, 2015 and 2016. |
COMMITMENTS AND CONTINGENCIES (
COMMITMENTS AND CONTINGENCIES (Notes) | 12 Months Ended |
Dec. 31, 2017 | |
Commitments and Contingencies [Line Items] | |
COMMITMENTS AND CONTINGENCIES | 13. COMMITMENTS AND CONTINGENCIES Commitments - Operating leases represent future minimum lease payments under noncancelable leases covering office space, facilities and information technology hardware and software. Rental expense was $8.7 million , $8.6 million and $5.0 million in 2017, 2016 and 2015 , respectively. The following table sets forth our operating lease payments for the periods indicated: Operating Leases ( Millions of dollars ) 2018 $ 4.7 2019 3.9 2020 3.7 2021 3.3 2022 3.3 Thereafter 3.2 Total $ 22.1 Environmental Matters - We are subject to multiple historical, wildlife preservation and environmental laws and/or regulations, which affect many aspects of our present and future operations. Regulated activities include, but are not limited to, those involving air emissions, storm water and wastewater discharges, handling and disposal of solid and hazardous wastes, wetland preservation, hazardous materials transportation, and pipeline and facility construction. These laws and regulations require us to obtain and/or comply with a wide variety of environmental clearances, registrations, licenses, permits and other approvals. Failure to comply with these laws, regulations, licenses and permits may expose us to fines, penalties and/or interruptions in our operations that could be material to our results of operations. In addition, emission controls and/or other regulatory or permitting mandates under the Clean Air Act and other similar federal and state laws could require unexpected capital expenditures. We cannot assure that existing environmental statutes and regulations will not be revised or that new regulations will not be adopted or become applicable to us. Revised or additional statutes or regulations that result in increased compliance costs or additional operating restrictions could have a material adverse effect on our business, financial condition and results of operations. Our expenditures for environmental investigation and remediation compliance to-date have not been significant in relation to our financial position, results of operations or cash flows, and our expenditures related to environmental matters had no material effects on earnings or cash flows during 2017, 2016 or 2015 . We own or retain legal responsibility for certain environmental conditions at 12 former MGP sites in Kansas. These sites contain contaminants generally associated with MGP sites and are subject to control or remediation under various environmental laws and regulations. A consent agreement with the KDHE governs all environmental investigation and remediation work at these sites. The terms of the consent agreement require us to investigate these sites and set remediation activities based upon the results of the investigations and risk analysis. Remediation typically involves the management of contaminated soils and may involve removal of structures and monitoring and/or remediation of groundwater. We have completed or addressed removal of the source of soil contamination at 11 of the 12 sites, and continue to monitor groundwater at eight of the 12 sites according to plans approved by the KDHE. Regulatory closure has been achieved at three of the 12 sites, but these sites remain subject to potential future requirements that may result in additional costs. During 2016, we completed a site assessment at the twelfth site where no active soil remediation has occurred. We have submitted a work plan to the KDHE for approval to address a source of contamination and associated contaminated soil on a portion of this site. We are also conducting a study of the feasibility of various options to address the remainder of the site. Costs associated with the remediation at this site are not expected to be material to our results of operations or financial position. With regard to one of our former MGP sites, periodic monitoring and a 2016 interim site investigation indicated elevated levels of contaminants generally associated with MGP sites. Additional testing and work plan development continued in 2017 to determine a remediation work plan to present to the KDHE for approval, which could impact our estimates of the cost of remediation at this site. In the fourth quarter of 2016, we estimated the potential costs associated with additional investigation and remediation to be in the range of $4.0 million to $7.0 million . A single reliable estimate of the remediation costs was not feasible due to the amount of uncertainty in the ultimate remediation approach that will be utilized. Accordingly, we recorded a reserve of $4.0 million for this site in the fourth quarter of 2016. In April 2017, Kansas Gas Service filed an application with the KCC seeking approval of an AAO associated with the costs incurred at, and nearby, the 12 former MGP sites which we own or retain responsibility for certain environmental conditions. In October 2017, Kansas Gas Service, the KCC staff and the Citizens’ Utility Ratepayer Board filed a unanimous settlement agreement with the KCC. The agreement allows Kansas Gas Service to defer and seek recovery of costs that are necessary for investigation and remediation at the 12 former MGP sites incurred after January 1, 2017, up to a cap of $15.0 million , net of any related insurance recoveries. Costs approved in a future rate proceeding would then be amortized over a 15-year period. The unamortized amounts will not be included in rate base or accumulate carrying charges. At the time future investigation and remediation work, net of any related insurance recoveries, is expected to exceed $15.0 million , Kansas Gas Service will be required to file an application with the KCC for approval to increase the $15.0 million cap. The KCC issued an order approving the settlement agreement in November 2017. A regulatory asset of approximately $5.9 million was recorded for estimated costs that have been accrued at January 1, 2017. Our expenditures for environmental evaluation, mitigation, remediation and compliance to date have not been significant in relation to our financial position, results of operations or cash flows, and our expenditures related to environmental matters had no material effects on earnings or cash flows during 2017, 2016 or 2015 . A number of environmental issues may exist with respect to MGP sites that are unknown to us. Accordingly, future costs are dependent on the final determination and regulatory approval of any remedial actions, the complexity of the site, level of remediation required, changing technology and governmental regulations, and to the extent not recovered by insurance or recoverable in rates from our customers, could be material to our financial condition, results of operations or cash flows. We are subject to environmental regulation by federal, state and local authorities. Due to the inherent uncertainties surrounding the development of federal and state environmental laws and regulations, we cannot determine with specificity the impact such laws may have on its existing and future facilities. With the trend toward stricter standards, greater regulation and more extensive permit requirements for the types of assets operated by us, our environmental expenditures could increase in the future, and such expenditures may not be fully recovered by insurance or recoverable in rates from our customers, and those costs may adversely affect our financial condition, results of operations and cash flows. We do not expect expenditures for these matters to have a material adverse effect on our financial condition, results of operations or cash flows. Pipeline Safety - We are subject to PHMSA regulations, including integrity-management regulations. PHMSA regulations require pipeline companies operating high-pressure transmission pipelines to perform integrity assessments on pipeline segments that pass through densely populated areas or near specifically designated high-consequence areas. In January 2012, the Pipeline Safety, Regulatory Certainty and Job Creation Act was signed into law. The law increased maximum penalties for violating federal pipeline safety regulations and directs the DOT and the Secretary of Transportation to conduct further review or studies on issues that may or may not be material to us. These issues include, but are not limited to, the following: • an evaluation of whether natural gas pipeline integrity-management requirements should be expanded beyond current high-consequence areas; • a verification of records for pipelines in class 3 and 4 locations and high-consequence areas to confirm maximum allowable operating pressures; and • a requirement to test previously untested pipelines operating above 30 percent yield strength in high-consequence areas. In April 2016, PHMSA published a NPRM, the Safety of Gas Transmission & Gathering Lines Rule, in the Federal Register to revise pipeline safety regulations applicable to the safety of onshore natural gas transmission and gathering pipelines. Proposals include changes to pipeline integrity management requirements and other safety-related requirements. The NPRM comment period ended July 7, 2016, and comments are under review by PHMSA. As part of the comment review process, PHMSA is being advised by the Technical Pipeline Safety Standards Committee, informally known by PHMSA as the GPAC, a statutorily mandated advisory committee that advises PHMSA on proposed safety policies for natural gas pipelines. The GPAC reviews PHMSA's proposed regulatory initiatives to assure the technical feasibility, reasonableness, cost-effectiveness and practicality of each proposal. The potential capital and operating expenditures associated with compliance with the proposed rule are currently being evaluated and could be significant depending on the final regulations. Legal Proceedings - We are a party to various litigation matters and claims that have arisen in the normal course of our operations. While the results of litigation and claims cannot be predicted with certainty, we believe the reasonably possible losses from such matters, individually and in the aggregate, are not material. Additionally, we believe the probable final outcome of such matters will not have a material adverse effect on our results of operations, financial position or cash flows. |
QUARTERLY FINANCIAL DATA (UNAUD
QUARTERLY FINANCIAL DATA (UNAUDITED) (Notes) | 12 Months Ended |
Dec. 31, 2017 | |
Schedule of Quarterly Financial Information [Line Items] | |
QUARTERLY FINANCIAL DATA (UNAUDITED) | 14. QUARTERLY FINANCIAL DATA (UNAUDITED) First Quarter Second Quarter Third Quarter Fourth Quarter Year Ended December 31, 2017 ( Thousands of dollars ) Revenues $ 550,408 $ 279,689 $ 247,142 $ 462,394 Operating income $ 125,132 $ 44,052 $ 40,780 $ 89,512 Net income $ 76,456 $ 20,623 $ 18,797 $ 47,119 Earnings per share Basic $ 1.45 $ 0.39 $ 0.36 $ 0.90 Diluted $ 1.44 $ 0.39 $ 0.36 $ 0.89 First Quarter Second Quarter Third Quarter Fourth Quarter Year Ended December 31, 2016 ( Thousands of dollars ) Revenues $ 508,364 $ 245,923 $ 232,191 $ 440,754 Operating income $ 116,073 $ 43,621 $ 30,892 $ 78,534 Net income $ 64,743 $ 20,300 $ 12,737 $ 42,315 Earnings per share Basic $ 1.23 $ 0.39 $ 0.24 $ 0.81 Diluted $ 1.22 $ 0.38 $ 0.24 $ 0.80 |
SUMMARY OF SIGNIFICANT ACCOUN23
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) | 12 Months Ended |
Dec. 31, 2017 | |
Significant Accounting Policies [Line Items] | |
Basis of Accounting | Basis of Presentation - The consolidated financial statements include the accounts of the natural gas distribution business as set forth in “Organization and Nature of Operations” above. All significant balances and transactions between our subsidiaries have been eliminated. |
Use of Estimates | Use of Estimates - The preparation of our consolidated financial statements and related disclosures in accordance with GAAP requires us to make estimates and assumptions with respect to values or conditions that cannot be known with certainty that affect the reported amount of assets and liabilities, and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements. These estimates and assumptions also affect the reported amounts of revenue and expenses during the reporting period. Items that may be estimated include, but are not limited to, the economic useful life of assets, fair value of assets and liabilities, provisions for doubtful accounts receivable, unbilled revenues for natural gas delivered but for which meters have not been read, natural gas purchased but for which no invoice has been received, provision for income taxes, including any deferred income tax valuation allowances, the results of litigation and various other recorded or disclosed amounts. We evaluate these estimates on an ongoing basis using historical experience and other methods we consider reasonable based on the particular circumstances. Nevertheless, actual results may differ significantly from the estimates. Any effects on our financial position or results of operations from revisions to these estimates are recorded in the period when the facts that give rise to the revision become known. |
Fair Value Measurement | Fair Value Measurements - We define fair value as the price that would be received from the sale of an asset or the transfer of a liability in an orderly transaction between market participants at the measurement date. We use the market and income approaches to determine the fair value of our assets and liabilities and consider the markets in which the transactions are executed. We measure the fair value of a group of financial assets and liabilities consistent with how a market participant would price the net risk exposure at the measurement date. Fair Value Hierarchy - At each balance sheet date, we utilize a fair value hierarchy to classify fair value amounts recognized or disclosed in our consolidated financial statements based on the observability of inputs used to estimate such fair value. The levels of the hierarchy are described below: • Level 1 - Unadjusted quoted prices in active markets for identical assets or liabilities; • Level 2 - Significant observable pricing inputs other than quoted prices included within Level 1 that are, either directly or indirectly, observable as of the reporting date. Essentially, this represents inputs that are derived principally from or corroborated by observable market data; and • Level 3 - May include one or more unobservable inputs that are significant in establishing a fair value estimate. These unobservable inputs are developed based on the best information available and may include our own internal data. We recognize transfers into and out of the levels as of the end of each reporting period. Determining the appropriate classification of our fair value measurements within the fair value hierarchy requires management’s judgment regarding the degree to which market data is observable or corroborated by observable market data. We categorize derivatives for which fair value is determined using multiple inputs within a single level, based on the lowest level input that is significant to the fair value measurement in its entirety. See Note 7 for additional information regarding our fair value measurements. |
Cash and Cash Equivalents | Cash and Cash Equivalents - Cash equivalents consist of highly liquid investments, which are readily convertible into cash and have original maturities of three months or less. |
Revenue Recognition | Revenue Recognition - For regulated deliveries of natural gas, we read meters and bill customers on a monthly cycle. We recognize revenues upon the delivery of the natural gas commodity or services rendered to customers. The billing cycles for customers do not necessarily coincide with the accounting periods used for financial reporting purposes. Revenues are accrued for natural gas delivered and services rendered to customers, but not yet billed. Accrued unbilled revenue is based on a percentage estimate of amounts unbilled each month, which is dependent upon a number of factors, some of which require management’s judgment. These factors include customer consumption patterns and the impact of weather on usage. The amounts of accrued unbilled natural gas sales revenues at December 31, 2017 and 2016 , were $138.5 million and $143.2 million , respectively. |
Accounts Receivable | Accounts Receivable - Accounts receivable represent valid claims against nonaffiliated customers for natural gas sold or services rendered, net of allowances for doubtful accounts. We assess the creditworthiness of our customers. Those customers who do not meet minimum standards are required to provide security, including deposits and other forms of collateral, when appropriate. With more than 2 million customers across three states, we are not exposed materially to a concentration of credit risk. We maintain an allowance for doubtful accounts based upon factors surrounding the credit risk of customers, historical trends, consideration of the current credit environment and other information. In Oklahoma, Kansas and most jurisdictions we serve in Texas, we are able to recover natural gas costs related to doubtful accounts through purchased-gas cost adjustment mechanisms. At December 31, 2017 and 2016 , our allowance for doubtful accounts was $4.8 million and $4.2 million , respectively. |
Inventories | Inventories - Natural gas in storage is maintained on the basis of weighted-average cost. Natural gas inventories that are injected into storage are recorded in inventory based on actual purchase costs, including storage and transportation costs. Natural gas inventories that are withdrawn from storage are accounted for in our purchased-gas cost adjustment mechanisms at the weighted-average inventory cost. Materials and supplies inventories are stated at the lower of weighted-average cost or net realizable value. |
Derivatives and Risk Management Activities | Derivatives and Risk Management Activities - We record all derivative instruments at fair value, with the exception of normal purchases and normal sales that are expected to result in physical delivery. The accounting for changes in the fair value of a derivative instrument depends on whether it has been designated and qualifies as part of a hedging relationship and, if so, the reason for holding it, or if regulatory rulings require a different accounting treatment. If certain conditions are met, we may elect to designate a derivative instrument as a hedge of exposure to changes in fair values or cash flows. The table below summarizes the various ways in which we account for our derivative instruments and the impact on our consolidated financial statements: Recognition and Measurement Accounting Treatment Balance Sheet Income Statement Normal purchases and normal sales - Fair value not recorded - Change in fair value not recognized in earnings Mark-to-market - Recorded at fair value - Change in fair value recognized in, and recoverable through, the purchased-gas cost adjustment mechanisms We have not elected to formally designate any of our derivative instruments as hedges. Gains or losses associated with the fair value of commodity derivative instruments entered into by us are included in, and recoverable through, the purchased-gas cost adjustment mechanisms. See Note 7 for additional information regarding our fair value measurements and hedging activities using derivatives. |
Property, Plant and Equipment | Property, Plant and Equipment - Our properties are stated at cost, which includes direct construction costs such as direct labor, materials, burden and AFUDC. Generally, the cost of our property retired or sold, plus removal costs, less salvage, is charged to accumulated depreciation. Gains and losses from sales or retirement of an entire operating unit or system of our properties are recognized in income. Maintenance and repairs are charged directly to expense. AFUDC represents the cost of borrowed funds used to finance construction activities. We capitalize interest costs during the construction or upgrade of qualifying assets. Capitalized interest is recorded as a reduction to interest expense. Our properties are depreciated using the straight-line method over their estimated useful lives. Generally, we apply composite depreciation rates to functional groups of property having similar economic circumstances. We periodically conduct depreciation studies to assess the economic lives of our assets. These depreciation studies are completed as a part of our regulatory proceedings, and the changes in economic lives, if applicable, are implemented prospectively when the new rates are approved by our regulators and become effective. Changes in the estimated economic lives of our property, plant and equipment could have a material effect on our financial position, results of operations or cash flows. Property, plant and equipment on our Consolidated Balance Sheets includes construction work in process for capital projects that have not yet been placed in service and therefore are not being depreciated. Assets are transferred out of construction work in process when they are substantially complete and ready for their intended use. See Note 9 for additional information regarding our property, plant and equipment. |
Impairment of Goodwill and Long-Lived Assets | Impairment of Goodwill and Long-Lived Assets - We assess our goodwill for impairment at least annually as of July 1. Our goodwill impairment analysis performed in 2017, 2016 and 2015 , utilized a qualitative assessment and did not result in any impairment indicators. Subsequent to July 1, 2017 , no event has occurred indicating that it is more likely than not that our fair value is less than our carrying value of our net assets. As part of our goodwill impairment test, we first assess qualitative factors (including macroeconomic conditions, industry and market considerations, cost factors and overall financial performance) to determine whether it is more likely than not that our fair value is less than our carrying amount. If further testing is necessary, we perform an impairment test for goodwill. This assessment is made by comparing our fair value with our book value, including goodwill. If the fair value is less than the book value, we will record an impairment charge, not to exceed the carrying amount of goodwill. To estimate our fair value, we use two generally accepted valuation approaches, an income approach and a market approach, using assumptions consistent with a market participant’s perspective. Under the income approach, we use anticipated cash flows over a period of years plus a terminal value and discount these amounts to their present value using appropriate discount rates. Under the market approach, we apply acquisition multiples to forecasted cash flows. The acquisition multiples used are consistent with historical market transactions. The forecasted cash flows are based on average forecasted cash flows over a period of years. We assess our long-lived assets for impairment whenever events or changes in circumstances indicate that an asset’s carrying amount may not be recoverable. An impairment is indicated if the carrying amount of a long-lived asset exceeds the sum of the undiscounted future cash flows expected to result from the use and eventual disposition of the asset. If an impairment is indicated, we record an impairment loss equal to the difference between the carrying value and the fair value of the long-lived asset. We determined that there were no asset impairments in 2017, 2016 or 2015 . |
Regulation | Regulation - We are subject to the rate regulation and accounting requirements of the OCC, KCC, RRC and various municipalities in Texas. We follow the accounting and reporting guidance for regulated operations. During the ratemaking process, regulatory authorities set the framework for what we can charge customers for our services and establish the manner that our costs are accounted for, including allowing us to defer recognition of certain costs and permitting recovery of the amounts through rates over time, as opposed to expensing such costs as incurred. Examples include weather normalization, unrecovered purchased-gas costs, pension and postemployment benefit costs and ad-valorem taxes. This allows us to stabilize rates over time rather than passing such costs on to the customer for immediate recovery. Actions by regulatory authorities could have an effect on the amount recovered from rate payers. Any difference in the amount recoverable and the amount deferred is recorded as income or expense at the time of the regulatory action. A write-off of regulatory assets and costs not recovered may be required if all or a portion of the regulated operations have rates that are no longer: • established by independent regulators; • designed to recover the specific entity’s costs of providing regulated services; and • set at levels that will recover our costs when considering the demand and competition for our services. See Note 8 for additional information regarding our regulatory assets and liabilities disclosures. |
Pension and Other Postretirement Plans | Pension and Other Postemployment Employee Benefits - We have defined benefit retirement plans covering eligible employees. We also sponsor welfare plans that provide other postemployment medical and life insurance benefits to eligible employees who retire with at least five years of service. To calculate the costs and liabilities related to our plans, we utilize an outside actuarial consultant, which uses statistical and other factors to anticipate future events. These factors include assumptions about the discount rate, expected return on plan assets, rate of future compensation increases, age and mortality and employment periods. We use tables issued by the Society of Actuaries to estimate mortality rates. In determining the projected benefit obligations and costs, assumptions can change from period to period and may result in material changes in the cost and liabilities we recognize. |
Income Taxes | Income Taxes - Deferred income taxes are recorded for the difference between the financial statement and income tax basis of assets and liabilities and carryforward items, based on income tax laws and rates existing at the time the temporary differences are expected to reverse. The effect on deferred income taxes of a change in tax rates is deferred and amortized for operations regulated by the OCC, KCC, RRC and various municipalities in Texas, if, as a result of an action by a regulator, it is probable that the effect of the change in tax rates will be recovered from or returned to customers through future rates. We continue to amortize previously deferred investment tax credits for ratemaking purposes over the periods prescribed by our regulators. A valuation allowance for deferred income tax assets is recognized when it is more likely than not that some or all of the benefit from the deferred income tax asset will not be realized. To assess that likelihood, we use estimates and judgment regarding our future taxable income, as well as the jurisdiction in which such taxable income is generated, to determine whether a valuation allowance is required. Such evidence can include our current financial position, our results of operations, both actual and forecasted, the reversal of deferred income tax liabilities, as well as the current and forecasted business economics of our industry. We had no valuation allowance at December 31, 2017 and 2016 . We utilize a more-likely-than-not recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position that is taken or expected to be taken in a tax return. We reflect penalties and interest as part of income tax expense as they become applicable for tax provisions that do not meet the more-likely-than-not recognition threshold and measurement attribute. There were no material uncertain tax positions at December 31, 2017 and 2016 . See Note 12 for additional information regarding income taxes. |
Asset Retirement Obligations | Asset Retirement Obligations - Asset retirement obligations represent legal obligations associated with the retirement of long-lived assets that result from the acquisition, construction, development and/or normal use of the asset. Certain long-lived assets that comprise our natural gas distribution systems, primarily our pipeline assets, are subject to agreements or regulations that give rise to an asset retirement obligation for removal or other disposition costs associated with retiring the assets in place upon the discontinued use of the natural gas distribution system. We recognize the fair value of a liability for an asset retirement obligation in the period when it is incurred if a reasonable estimate of the fair value can be made. We are not able to estimate reasonably the fair value of the asset retirement obligations for portions of our assets because the settlement dates are indeterminable given our expected continued use of the assets with proper maintenance. We expect our natural gas distribution systems will continue in operation as long as natural gas supply and demand for natural gas distribution service exists. Based on the widespread use of natural gas for heating and cooking activities by residential and commercial customers in our service areas, management expects supply and demand to exist for the foreseeable future. In accordance with long-standing regulatory treatment, we collect through rates the estimated costs of removal on certain regulated properties through depreciation expense, with a corresponding credit to accumulated depreciation and amortization. These removal costs collected through our rates include costs attributable to legal and nonlegal removal obligations; however, the amounts collected that are in excess of these nonlegal asset-removal costs incurred are accounted for as a regulatory liability for financial reporting purposes. Historically, with the exception of the regulatory authority in Kansas, the regulatory authorities that have jurisdiction over our regulated operations have not required us to quantify or disclose this amount; rather, these costs are addressed prospectively in depreciation rates and are set in each general rate order. We have made an estimate of our regulatory liability using current rates since the last general rate order in each of our jurisdictions if the removal costs collected have exceeded our removal cost incurred; however, for financial reporting purposes, significant uncertainty exists regarding the future disposition of this regulatory liability, pending, among other issues, clarification of regulatory intent. We continue to monitor the regulatory requirements, and the liability may be adjusted as more information is obtained. We record the estimated asset removal obligation in noncurrent liabilities in other deferred credits on our Consolidated Balance Sheets. To the extent this estimated liability is adjusted, such amounts will be reclassified between accumulated depreciation and amortization and other deferred credits and therefore will not have an impact on earnings. |
Contingencies | Contingencies - Our accounting for contingencies covers a variety of business activities, including contingencies for legal and environmental exposures. We accrue these contingencies when our assessments indicate that it is probable that a liability has been incurred or an asset will not be recovered and an amount can be estimated reasonably. We expense legal fees as incurred and base our legal liability estimates on currently available facts and our estimates of the ultimate outcome or resolution. Accruals for estimated losses from environmental remediation obligations generally are recognized no later than the completion of a remediation feasibility study. Recoveries of environmental remediation costs from other parties are recorded as assets when their receipt is deemed probable. Actual results may differ from our estimates resulting in an impact, positive or negative, on earnings. See Note 13 for additional information regarding contingencies. |
Share-Based Payments | Share-Based Payments - We expense the fair value of share-based payments net of estimated forfeitures. We estimate forfeiture rates based on historical forfeitures under our share-based payment plans. |
Earnings Per Share | Earnings per share - Basic EPS is based on net income and is calculated based upon the daily weighted-average number of common shares outstanding during the periods presented. Also, this calculation includes fully vested stock awards that have not yet been issued as common stock. Diluted EPS includes the above, plus unvested stock awards granted under our compensation plans, but only to the extent these instruments dilute earnings per share. |
Segments | Segments - We operate in one reportable business segment: regulated public utilities that deliver natural gas to residential, commercial, industrial, wholesale, public authority and transportation customers. We define reportable business segments as components of an organization for which discrete financial information is available and operating results are evaluated on a regular basis by the chief operating decision maker (“CODM”) in order to assess performance and allocate resources. Our CODM is our Chief Executive Officer (“CEO”). Characteristics of our organization that were relied upon in making this determination include the similar nature of services we provide, the functional alignment of our organizational structure, and the reports that are regularly reviewed by the CODM for the purpose of assessing performance and allocating resources. Our management is functionally aligned and centralized, with performance evaluated based upon results of the entire distribution business. Capital allocation decisions are driven by asset integrity management, operating efficiency, growth opportunities and government relocations, not geographic location or regulatory jurisdiction. In 2017 , 2016 and 2015 , we had no single external customer from which we received 10 percent or more of our gross revenues. |
Treasury Stock | Treasury Stock - We record treasury stock purchases at cost, which includes incremental direct transaction costs. Amounts are recorded as reductions in equity in our Consolidated Balance Sheets. We record the reissuance of treasury stock at our weighted average cost of treasury shares recorded in equity in our Consolidated Balance Sheets. |
Recently Issues Accounting Standards Updates | Recently Issued Accounting Standards Update - In February 2018, the FASB issued ASU 2018-02, “Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income,’’ which allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017. This new guidance is required for our interim and annual reports for periods beginning after December 15, 2018, and early adoption is permitted. We are currently assessing the timing and impacts of adopting this standard, but do not expect a material impact to our consolidated financial statements. In August 2017, the FASB issued ASU 2017-12, “Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities,” which allows more types of hedging strategies to be eligible for hedge accounting and simplifies application of hedge accounting. This new guidance is required for our interim and annual reports for periods beginning after December 15, 2018, and early adoption is permitted, but must be applied as of the beginning of the fiscal year, or initial application date. The impact of this guidance is not material to us, as we have not elected hedge accounting due to the nature of the types of derivatives we have entered. In March 2017, the FASB issued ASU 2017-07, “Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost,” which requires (1) separation of net periodic service costs for pension and other postemployment benefits into service cost and other components, (2) presentation of the service cost component in the same line as other compensation costs rendered by pertinent employees during the period, and (3) reporting the other components of net periodic benefit costs separately from the service cost component and outside a subtotal of income from operations. Additionally, only the service cost component is eligible for capitalization for GAAP, when applicable. However, all of our cost components remain eligible for capitalization under the accounting requirements for rate regulated entities. We will adopt this guidance for our interim and annual reports in the first quarter of 2018. When adopted, the presentation changes required for net periodic benefit costs will not impact previously reported net income; however, the reclassification of the other components of benefits costs will result in an increase in operating income and an increase in other expenses for 2017 and 2016 of $17.3 million and $19.8 million , respectively. We will use the retroactive presentation that permits the use of the amounts disclosed for the various components of net benefit cost in our Employee Benefit Plans footnote to our consolidated financial statements as the basis for the retrospective application. In addition, we updated our information systems for the capitalization of service costs to property and non-service costs to a regulatory asset on a prospective basis, as well as the appropriate accounts for non-service costs to apply retroactive reclassification. In January 2017, the FASB issued ASU 2017-04, “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment,” which simplifies how an entity is required to test goodwill for impairment by eliminating Step 2 of the goodwill test, where the measurement of a goodwill impairment loss was determined by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. Upon adoption, a goodwill impairment will be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. We early adopted this new guidance in the current year, and it did not have an impact on our consolidated financial statements. See our conclusions regarding our current year Goodwill Impairment Test above. In June 2016, the FASB issued ASU 2016-13, “Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments,’’ which introduced new guidance to the accounting for credit losses on instruments within its scope, including trade receivables. It is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, and may be adopted a year earlier. The new guidance will be initially applied through a cumulative-effect adjustment to retained earnings as of the beginning of the period of adoption. We are currently assessing the timing and impacts of adopting this standard, which must be adopted by the first quarter of 2020. In March 2016, the FASB issued ASU 2016-09, “Improvements to Employee Share-Based Payment Accounting,” which includes various new aspects to simplify how share-based payments are accounted for and presented in the consolidated financial statements. The new standard modifies several aspects of the accounting and reporting for employee share-based payments and related tax accounting impacts, including the presentation in the consolidated statements of operations and cash flows. We adopted this new guidance in the first quarter 2017, and in accordance with the transition requirements, we recorded $5.2 million of excess tax benefit in income tax expense and have transitioned all provisions of this new guidance prospectively, other than our presentation of our withholding shares for tax-withholding purposes, which we accounted for retrospectively in the Financing Activities section of our Consolidated Statement of Cash Flows. We recorded a noncash cumulative-effect increase of $11.0 million to retained earnings, with an offset to a deferred income tax asset, as of the beginning of the reporting period in 2017, for excess tax benefits earned prior to January 1, 2017, that had not been recognized. We continue our use of the estimation method to account for share unit award forfeitures rather than actual forfeitures. The retrospective impact of our withholding shares for tax-withholding purposes to our Consolidated Statement of Cash Flows for the year ended December 31, 2016 , was a $9.0 million increase to net cash provided by operating activities and a $9.0 million decrease to net cash used in financing activities. The retrospective impact of our withholding shares for tax-withholding purposes to our Consolidated Statement of Cash Flows for the year ended December 31, 2015 , was a $13.7 million increase to net cash provided by operating activities and a $13.7 million decrease to net cash used in financing activities. In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842),” which prescribes recognizing lease assets and liabilities on the balance sheet and includes disclosure of key information about leasing arrangements. A modified retrospective transition approach is required for leases existing at the time of adoption. In January 2018, the FASB issued ASU 2018-01, “Leases (Topic 842),” as an amendment to address stakeholder concerns about the costs and complexity of complying with the transition provisions of the new lease requirements to provide an optional transition practical expedient to not evaluate under Topic 842 existing or expired land easements that were not previously accounted for as leases under the current leases guidance in Topic 840. We are continuing to evaluate our population of leases, analyzing lease agreements, and holding meetings with cross-functional teams to determine the potential impact of this accounting standard on our financial position and results of operations and the transition approach we will utilize. We will adopt this new guidance in the first quarter of 2019. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers” (“ASC 606”), which clarifies and converges the revenue recognition principles under GAAP and International Financial Reporting Standards. In July 2015, FASB delayed the effective date for one year. We have evaluated all of our sources of revenue to determine the potential effect on our financial position, results of operations, cash flows and the related accounting policies and business processes. We will adopt this new guidance for our interim and annual reports beginning in the first quarter 2018, using the modified retrospective method. There will not be a cumulative adjustment to our opening retained earnings. The only impact we expect would be a reclassification of certain revenues that do not meet the requirements under ASC 606 as revenues from contracts with customers, but will continue to be reflected as other revenues in determining total revenue. The items we expect to reclassify relate primarily to the weather normalization mechanism in Kansas, where the KCC determines how we reflect variations in weather in our rates billed to customers. We have determined the majority of our tariffs to be contracts with customers which are settled over time, where our performance obligation is settled with our customer when natural gas is delivered and simultaneously consumed. The majority of our revenues that meet the requirements under ASC 606 are considered implied contracts, as established by our tariff rates approved by regulatory authorities. Our sources of revenue will be disaggregated by natural gas sales (including sales to residential, commercial, industrial, wholesale and public authority customers), transportation revenue, and other utility revenues, which are primarily one-time service fees, that meet the requirements under ASC 606. The reclassification of certain revenues that do not meet the requirements under ASC 606 will be classified as other revenues on the Consolidated Income Statement and in our Notes to Consolidated Financial Statements. Additionally, for our natural gas sales and transportation revenues, our customers receive the benefits of our performance when the commodity is delivered to the customer and the performance obligation is satisfied over time as the customer receives and consumes the natural gas. For our other utility revenue, the performance obligation of one time services are satisfied at a point in time when services are rendered to the customer. In addition, we will use the invoice method practical expedient, where we will recognize revenue for volumes delivered for which we have a right to invoice. |
ACCUMULATED OTHER COMPREHENSI24
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Accumulated Other Comprehensive Income (Loss) [Line Items] | |
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] | The following table sets forth the balance in accumulated other comprehensive income (loss) for the period indicated: Accumulated Other Comprehensive Income (Loss) (Thousands of dollars) January 1, 2016 $ (4,401 ) Pension and other postemployment benefit plans obligations Other comprehensive income (loss) before reclassification, net of tax of $486 (776 ) Amounts reclassified from accumulated other comprehensive income (loss), net of tax of $(289) 462 Other comprehensive income (loss) (314 ) December 31, 2016 (4,715 ) Pension and other postemployment benefit plans obligations Other comprehensive income (loss) before reclassification, net of tax of $808 (1,293 ) Amounts reclassified from accumulated other comprehensive income (loss), net of tax of $(322) 515 Other comprehensive income (loss) (778 ) December 31, 2017 $ (5,493 ) |
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] | The following table sets forth the effect of reclassifications from accumulated other comprehensive income (loss) on our Consolidated Statements of Income for the period indicated: Affected Line Item in the Details about Accumulated Other Comprehensive Income Year Ended December 31, Consolidated Statements of (Loss) Components 2017 2016 2015 Income ( Thousands of dollars ) Pension and other postemployment benefit plan obligations (a) Amortization of net loss $ 42,591 $ 40,912 $ 47,494 Amortization of unrecognized prior service cost (4,597 ) (3,316 ) (1,962 ) 37,994 37,596 45,532 Regulatory adjustments (b) (37,157 ) (36,845 ) (44,615 ) 837 751 917 Income before income taxes (322 ) (289 ) (353 ) Income tax expense Total reclassifications for the period $ 515 $ 462 $ 564 Net income (a) These components of accumulated other comprehensive income (loss) are included in the computation of net periodic benefit cost. See Note 11 for additional information regarding our net periodic benefit cost. (b) Regulatory adjustments represent pension and other postemployment benefit costs expected to be recovered through rates and are deferred as part of our regulatory assets. See Note 8 for additional information regarding our regulatory assets and liabilities. |
EARNINGS PER SHARE (Tables)
EARNINGS PER SHARE (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
EARNINGS PER SHARE OF COMMON STOCK, BASIC AND DILUTED [Line Items] | |
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] | The following tables set forth the computation of basic and diluted EPS from continuing operations for the periods indicated: Year Ended December 31, 2017 Income Shares Per Share Amount ( Thousands, except per share amounts ) Basic EPS Calculation Net income available for common stock $ 162,995 52,527 $ 3.10 Diluted EPS Calculation Effect of dilutive securities — 452 Net income available for common stock and common stock equivalents $ 162,995 52,979 $ 3.08 Year Ended December 31, 2016 Income Shares Per Share Amount ( Thousands, except per share amounts ) Basic EPS Calculation Net income available for common stock $ 140,095 52,453 $ 2.67 Diluted EPS Calculation Effect of dilutive securities — 510 Net income available for common stock and common stock equivalents $ 140,095 52,963 $ 2.65 Year Ended December 31, 2015 Income Shares Per Share Amount ( Thousands, except per share amounts ) Basic EPS Calculation Net income available for common stock $ 119,030 52,578 $ 2.26 Diluted EPS Calculation Effect of dilutive securities — 676 Net income available for common stock and common stock equivalents $ 119,030 53,254 $ 2.24 |
REGULATORY ASSETS AND LIABILI26
REGULATORY ASSETS AND LIABILITIES (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items] | |
SCHEDULE OF REGULATED ASSETS AND LIABILITIES | The table below presents a summary of regulatory assets, net of amortization, and liabilities for the periods indicated: December 31, 2017 Remaining Recovery Period Current Noncurrent Total ( Thousands of dollars ) Under-recovered purchased-gas costs 1 year $ 41,238 $ — $ 41,238 Pension and other postemployment benefit costs See Note 11 25,156 387,582 412,738 Weather normalization 1 year 17,461 — 17,461 Reacquired debt costs 10 years 812 7,298 8,110 MGP remediation costs 15 years — 6,104 6,104 Other 1 to 21 years 3,513 4,205 7,718 Total regulatory assets, net of amortization 88,180 405,189 493,369 Federal income tax rate changes (a) See Note 12 — (519,421 ) (519,421 ) Over-recovered purchased-gas costs 1 year (9,434 ) — (9,434 ) Ad-valorem tax 1 year (4 ) — (4 ) Total regulatory liabilities (9,438 ) (519,421 ) (528,859 ) Net regulatory assets and liabilities $ 78,742 $ (114,232 ) $ (35,490 ) (a) See Note 12 for additional information regarding our federal income tax rate changes regulatory liabilities. December 31, 2016 Remaining Recovery Period Current Noncurrent Total ( Thousands of dollars ) Under-recovered purchased-gas costs 1 year $ 29,901 $ — $ 29,901 Pension and other postemployment benefit costs See Note 11 31,498 427,448 458,946 Weather normalization 1 year 17,661 — 17,661 Reacquired debt costs 11 years 812 8,108 8,920 Other 1 to 22 years 3,274 4,966 8,240 Total regulatory assets, net of amortization 83,146 440,522 523,668 Over-recovered purchased-gas costs 1 year (10,154 ) — (10,154 ) Ad-valorem tax 1 year (1,768 ) — (1,768 ) Total regulatory liabilities (11,922 ) — (11,922 ) Net regulatory assets and liabilities $ 71,224 $ 440,522 $ 511,746 |
PROPERTY, PLANT AND EQUIPMENT27
PROPERTY, PLANT AND EQUIPMENT (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Regulated [Member] | |
Property, Plant and Equipment [Line Items] | |
Property, Plant and Equipment by Property Type | The following table sets forth our property, plant and equipment by property type, for the periods indicated: December 31, December 31, 2017 2016 ( Thousands of dollars ) Natural gas distribution pipelines and related equipment $ 4,572,343 $ 4,321,429 Natural gas transmission pipelines and related equipment 497,791 481,953 General plant and other 513,445 530,459 Construction work in process 130,333 70,327 Property, plant and equipment 5,713,912 5,404,168 Accumulated depreciation and amortization (1,706,327 ) (1,672,548 ) Net property, plant and equipment $ 4,007,585 $ 3,731,620 |
SHARE-BASED PAYMENTS (Tables)
SHARE-BASED PAYMENTS (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Share-based Payments [Line Items] | |
Schedule of Share-based Compensation, Restricted Stock Units Activity | The following tables set forth activity and various statistics for restricted stock unit awards outstanding under the respective plans for the period indicated: Number of Units Weighted- Average Price Nonvested at December 31, 2016 194,900 $ 41.68 Granted 37,825 $ 63.97 Vested (85,490 ) $ 33.76 Forfeited (6,570 ) $ 52.65 Nonvested at December 31, 2017 140,665 $ 51.97 2017 2016 2015 Weighted-average grant date fair value (per share) $ 63.97 $ 58.30 $ 41.40 Fair value of shares granted (thousands of dollars) $ 2,420 $ 2,503 $ 3,141 |
Schedule of Nonvested Performance-based Units Activity | The following tables set forth activity and various statistics related to our performance stock unit awards and the assumptions used by us in the valuations of the 2017, 2016 and 2015 grants at the grant date: Number of Units Weighted- Average Price Nonvested at December 31, 2016 288,811 $ 46.06 Granted 74,120 $ 68.94 Vested (117,626 ) $ 35.98 Forfeited (7,981 ) $ 58.58 Nonvested at December 31, 2017 237,324 $ 57.78 2017 2016 2015 Volatility (a) 20.70% 18.20% 15.90% Dividend yield 2.63% 2.40% 2.90% Risk-free interest rate 1.48% 0.91% 1.10% (a) - Volatility based on historical volatility over three years using daily stock price observations of our peer utilities. 2017 2016 2015 Weighted-average grant date fair value (per share) $ 68.94 $ 64.06 $ 44.48 Fair value of shares granted (thousands of dollars) $ 5,110 $ 4,766 $ 4,486 |
EMPLOYEE BENEFIT PLANS (Tables)
EMPLOYEE BENEFIT PLANS (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Defined Benefit Plans and Other Postemployment Benefit Plans Table Text Block [Line Items] | |
Schedule of Assumptions Used [Table Text Block] | Actuarial Assumptions - The following table sets forth the weighted-average assumptions used to determine benefit obligations for pension and postemployment benefits for the periods indicated: December 31, 2017 2016 Discount rate - pension plans 3.80% 4.30% Discount rate - other postemployment plans 3.70% 4.20% Compensation increase rate 3.25% - 3.35% 3.25% - 3.40% The following table sets forth the weighted-average assumptions used by us to determine the periodic benefit costs for the periods indicated: Years Ended December 31, 2017 2016 2015 Discount rate - pension plans 4.30% 4.75% 4.25%/4.75% (c) Discount rate - other postemployment plans 4.20% 4.75%/3.75% (a) 4.25%/4.75% (c) Expected long-term return on plan assets - pension plans 7.75% 7.75% 7.75% Expected long-term return on plan assets - other postemployment plans 7.60% 8.00%/7.75% (b) 7.75% Compensation increase rate 3.25% - 3.40% 3.35% - 3.40% 3.30% - 3.50% |
Schedule of Defined Benefit Plans Disclosures [Table Text Block] | The following table sets forth our defined benefit pension and other postemployment benefit plans, benefit obligations and fair value of plan assets for the periods indicated: Pension Benefits Other Postemployment Benefits December 31, December 31, 2017 2016 2017 2016 Changes in Benefit Obligation (Thousands of dollars) Benefit obligation, beginning of period $ 966,531 $ 985,624 $ 243,548 $ 228,253 Service cost 12,176 12,055 2,509 2,675 Interest cost 40,453 45,550 9,890 10,235 Plan participants’ contributions — — 3,483 3,043 Actuarial loss (gain) 76,325 25,886 12,129 14,309 Benefits paid (55,107 ) (71,066 ) (16,690 ) (15,450 ) Plan amendment — — 171 483 Settlements (46,487 ) (31,518 ) — — Benefit obligation, end of period 993,891 966,531 255,040 243,548 Change in Plan Assets Fair value of plan assets, beginning of period 739,586 785,161 166,046 155,495 Actual return on plan assets 135,056 48,768 31,228 9,733 Employer contributions 111,936 12,441 6,159 13,225 Plan participants’ contributions — — 3,483 3,043 Benefits paid (55,107 ) (71,066 ) (16,690 ) (15,450 ) Settlements (46,667 ) (35,718 ) — — Fair value of assets, end of period 884,804 739,586 190,226 166,046 Balance at December 31 $ (109,087 ) $ (226,945 ) $ (64,814 ) $ (77,502 ) Current liabilities $ (963 ) $ (941 ) $ — $ — Noncurrent liabilities (108,124 ) (226,004 ) (64,814 ) (77,502 ) Balance at December 31 $ (109,087 ) $ (226,945 ) $ (64,814 ) $ (77,502 ) |
Schedule of Net Benefit Costs [Table Text Block] | Components of Net Periodic Benefit Cost - The following tables set forth the components of net periodic benefit cost for our defined benefit pension and other postemployment benefit plans for the period indicated: Pension Benefits Year Ended December 31, 2017 2016 2015 (Thousands of dollars) Components of net periodic benefit cost Service cost $ 12,176 $ 12,055 $ 13,660 Interest cost 40,453 45,550 43,542 Expected return on assets (58,496 ) (61,183 ) (61,769 ) Amortization of unrecognized prior service cost — — 266 Amortization of net loss 36,107 35,543 42,226 Settlements — — 27 Net periodic benefit cost $ 30,240 $ 31,965 $ 37,952 Other Postemployment Benefits Year Ended December 31, 2017 2016 2015 (Thousands of dollars) Components of net periodic benefit cost Service cost $ 2,509 $ 2,675 $ 3,257 Interest cost 9,890 10,235 10,628 Expected return on assets (12,590 ) (12,370 ) (11,892 ) Amortization of unrecognized prior service cost (4,597 ) (3,316 ) (2,228 ) Amortization of net loss 6,484 5,369 5,268 Net periodic benefit cost $ 1,696 $ 2,593 $ 5,033 |
Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block] | Other Comprehensive Income (Loss) - The following table sets forth the amounts recognized in other comprehensive income (loss) related to our defined benefit pension benefits for the period indicated: Pension Benefits Year Ended December 31, 2017 2016 2015 (Thousands of dollars) Net gain (loss) arising during the period $ (2,101 ) $ (1,262 ) $ 339 Amortization of loss 837 751 917 Deferred income taxes 486 197 (483 ) Total recognized in other comprehensive income (loss) $ (778 ) $ (314 ) $ 773 |
Schedule of Net Periodic Benefit Cost Not yet Recognized [Table Text Block] | The tables below set forth the amounts in accumulated other comprehensive income (loss) that had not yet been recognized as components of net periodic benefit expense for the periods indicated: Pension Benefits December 31, 2017 2016 (Thousands of dollars) Prior service credit (cost) $ — $ — Accumulated loss (378,595 ) (414,757 ) Accumulated other comprehensive loss before regulatory assets (378,595 ) (414,757 ) Regulatory asset for regulated entities 369,647 407,073 Accumulated other comprehensive loss after regulatory assets (8,948 ) (7,684 ) Deferred income taxes 3,455 2,969 Accumulated other comprehensive loss, net of tax $ (5,493 ) $ (4,715 ) Other Postemployment Benefits December 31, 2017 2016 (Thousands of dollars) Prior service credit (cost) $ 5,442 $ 10,211 Accumulated loss (49,030 ) (62,084 ) Accumulated other comprehensive loss before regulatory assets (43,588 ) (51,873 ) Regulatory asset for regulated entities 43,588 51,873 Accumulated other comprehensive loss after regulatory assets — — Deferred income taxes — — Accumulated other comprehensive loss, net of tax $ — $ — |
Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year [Table Text Block] | The following table sets forth the amounts recognized in either accumulated comprehensive income (loss) or regulatory assets expected to be recognized as components of net periodic benefit expense in the next fiscal year: Pension Benefits Other Postemployment Benefits Amounts to be recognized in 2018 (Thousands of dollars) Prior service credit (cost) $ — $ (4,567 ) Actuarial net loss $ 39,913 $ 3,887 |
Schedule of Health Care Cost Trend Rates [Table Text Block] | Health Care Cost Trend Rates - The following table sets forth the assumed health care cost-trend rates for the periods indicated: 2017 2016 Health care cost-trend rate assumed for next year 7.00% 7.25% Rate to which the cost-trend rate is assumed to decline (the ultimate trend rate) 5.00% 5.00% Year that the rate reaches the ultimate trend rate 2023 2022 |
Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates [Table Text Block] | Assumed health care cost-trend rates have a significant effect on the amounts reported for our health care plans. A one percentage point change in assumed health care cost-trend rates would have the following effects: One Percentage One Percentage Point Increase Point Decrease (Thousands of dollars) Effect on total of service and interest cost $ 239 $ (238 ) Effect on other postemployment benefit obligation $ 2,906 $ (3,006 ) |
Schedule of Allocation of Plan Assets [Table Text Block] | Plan Assets - Our investment strategy is to invest plan assets in accordance with sound investment practices that emphasize long-term fundamentals. The goal of this strategy is to maximize investment returns while managing risk in order to meet the plan’s current and projected financial obligations. To achieve this strategy, we have established a liability-driven investment strategy to change the allocations as the plan reaches certain funded status. The plan’s investments include a diverse blend of various domestic and international equities, investment-grade debt securities which mirror the cash flows of our liability, insurance contracts and alternative investments. The current target allocation for the assets of our defined benefit pension plan is as follows: Investment-grade bonds 40.0 % U.S. large-cap equities 18.0 % Alternative investments 14.0 % Developed foreign large-cap equities 10.0 % Mid-cap equities 7.0 % Emerging markets equities 6.0 % Small-cap equities 5.0 % Total 100 % As part of our risk management for the plans, minimums and maximums have been set for each of the asset classes listed above. All investment managers for the plan are subject to certain restrictions on the securities they purchase and, with the exception of indexing purposes, are prohibited from owning our stock. The current target allocation for the assets of our other postemployment benefits plan is 30 percent fixed income securities and 70 percent equity securities. The following tables set forth our pension benefits and other postemployment benefits plan assets by fair value category as of the measurement date: Pension Benefits December 31, 2017 Asset Category Level 1 Level 2 Level 3 Total (Thousands of dollars) Investments: Equity securities (a) $ 301,911 $ 91,014 $ — $ 392,925 Government obligations — 74,596 — 74,596 Corporate obligations (b) — 260,907 — 260,907 Cash and money market funds (c) 21,139 20,787 — 41,926 Insurance contracts and group annuity contracts — — 35,158 35,158 Other investments (d) — 585 78,707 79,292 Total assets $ 323,050 $ 447,889 $ 113,865 $ 884,804 (a) - This category represents securities of the various market sectors from diverse industries. (b) - This category represents bonds from diverse industries. (c) - This category is primarily money market funds. (d) - This category represents alternative investments such as hedge funds and other financial instruments. Pension Benefits December 31, 2016 Asset Category Level 1 Level 2 Level 3 Total (Thousands of dollars) Investments: Equity securities (a) $ 371,655 $ 58,987 $ — $ 430,642 Government obligations — 47,445 — 47,445 Corporate obligations (b) — 129,036 — 129,036 Cash and money market funds (c) 13,786 16,114 — 29,900 Insurance contracts and group annuity contracts — — 45,140 45,140 Other investments (d) — 71 57,352 57,423 Total assets $ 385,441 $ 251,653 $ 102,492 $ 739,586 (a) - This category represents securities of the various market sectors from diverse industries. (b) - This category represents bonds from diverse industries. (c) - This category is primarily money market funds. (d) - This category represents alternative investments such as hedge funds and other financial instruments. Other Postemployment Benefits December 31, 2017 Asset Category Level 1 Level 2 Level 3 Total (Thousands of dollars) Investments: Equity securities (a) $ 63,180 $ 123 $ — $ 63,303 Government obligations — 101 — 101 Corporate obligations (b) — 25,905 — 25,905 Cash and money market funds (c) 4,512 28 — 4,540 Insurance contracts and group annuity contracts — 96,377 — 96,377 Total assets $ 67,692 $ 122,534 $ — $ 190,226 (a) - This category represents securities of the various market sectors from diverse industries. (b) - This category represents bonds from diverse industries. (c) - This category is primarily money market funds. Other Postemployment Benefits December 31, 2016 Asset Category Level 1 Level 2 Level 3 Total (Thousands of dollars) Investments: Equity securities (a) $ 39,817 $ 7,323 $ — $ 47,140 Government obligations — 75 — 75 Corporate obligations (b) — 19,948 — 19,948 Cash and money market funds (c) 74 16,989 — 17,063 Insurance contracts and group annuity contracts — 81,820 — 81,820 Total assets $ 39,891 $ 126,155 $ — $ 166,046 (a) - This category represents securities of the various market sectors from diverse industries. (b) - This category represents bonds from diverse industries. (c) - This category is primarily money market funds. |
Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets [Table Text Block] | The following table sets forth the reconciliation of Level 3 fair value measurements of our pension plans for the periods indicated: Pension Benefits Insurance Contracts Other Investments Total (Thousands of dollars) January 1, 2016 $ 56,465 $ 57,972 $ 114,437 Net realized and unrealized gains (losses) 4,518 (620 ) 3,898 Settlements (15,843 ) — (15,843 ) December 31, 2016 $ 45,140 $ 57,352 $ 102,492 Net realized and unrealized gains (losses) 2,569 5,055 7,624 Purchases — 16,300 16,300 Sales and settlements (12,551 ) — (12,551 ) December 31, 2017 $ 35,158 $ 78,707 $ 113,865 |
Schedule of Expected Benefit Payments [Table Text Block] | The following table sets forth the pension benefits and other postemployment benefits payments expected to be paid in 2018-2027: Pension Benefits Other Postemployment Benefits to be paid in: (Thousands of dollars) 2018 $ 50,875 $ 17,293 2019 $ 51,635 $ 17,383 2020 $ 52,518 $ 17,538 2021 $ 53,516 $ 17,485 2022 $ 54,289 $ 17,558 2023 through 2027 $ 286,188 $ 85,543 |
INCOME TAXES (Tables)
INCOME TAXES (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Income tax [Line Items] | |
Reconciliation of Income Tax Provision | The following table sets forth our provision for income taxes for the periods indicated: Years Ended December 31, 2017 2016 2015 ( Thousands of dollars ) Current income tax provision Federal $ — $ (2,016 ) $ 7,135 State 750 471 2,055 Total current income tax provision 750 (1,545 ) 9,190 Deferred income tax provision Federal 83,138 76,247 56,440 State 9,255 10,541 7,349 Total deferred income tax provision 92,393 86,788 63,789 Total provision for income taxes $ 93,143 $ 85,243 $ 72,979 |
Schedule of Effective Income Tax Rate Reconciliation | The following table is a reconciliation of our income tax provision for the periods indicated: Years Ended December 31, 2017 2016 2015 ( Thousands of dollars ) Income before income taxes $ 256,138 $ 225,338 $ 192,009 Federal statutory income tax rate 35 % 35 % 35 % Provision for federal income taxes 89,648 78,868 67,203 State income taxes, net of federal tax benefit 6,503 7,158 6,114 Nonregulated deferred tax rate decrease 2,162 — — Tax benefit of employee share based compensation (5,162 ) — — Other, net (8 ) (783 ) (338 ) Total provision for income taxes $ 93,143 $ 85,243 $ 72,979 |
Schedule of Deferred Tax Assets and Liabilities | The following table sets forth the tax effects of temporary differences that gave rise to significant portions of the deferred tax assets and liabilities for the periods indicated: December 31, 2017 2016 ( Thousands of dollars ) Deferred tax assets Employee benefits and other accrued liabilities $ 40,277 $ 123,333 Regulatory adjustments for enacted tax rate changes 129,421 — Net operating loss 24,712 23,094 Other 2,984 5,716 Total deferred tax assets 197,394 152,143 Deferred tax liabilities Excess of tax over book depreciation 677,249 990,682 Purchased-gas cost adjustment 13,805 13,822 Other regulatory assets and liabilities, net 106,285 186,207 Total deferred tax liabilities 797,339 1,190,711 Net deferred tax liabilities $ 599,945 $ 1,038,568 |
COMMITMENTS AND CONTINGENCIES31
COMMITMENTS AND CONTINGENCIES (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Commitments and Contingencies [Line Items] | |
Future Minimum Rental Payments for Operating Leases | The following table sets forth our operating lease payments for the periods indicated: Operating Leases ( Millions of dollars ) 2018 $ 4.7 2019 3.9 2020 3.7 2021 3.3 2022 3.3 Thereafter 3.2 Total $ 22.1 |
QUARTERLY FINANCIAL DATA (UNA32
QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Schedule of Quarterly Financial Information [Line Items] | |
Quarterly Financial Data | First Quarter Second Quarter Third Quarter Fourth Quarter Year Ended December 31, 2017 ( Thousands of dollars ) Revenues $ 550,408 $ 279,689 $ 247,142 $ 462,394 Operating income $ 125,132 $ 44,052 $ 40,780 $ 89,512 Net income $ 76,456 $ 20,623 $ 18,797 $ 47,119 Earnings per share Basic $ 1.45 $ 0.39 $ 0.36 $ 0.90 Diluted $ 1.44 $ 0.39 $ 0.36 $ 0.89 First Quarter Second Quarter Third Quarter Fourth Quarter Year Ended December 31, 2016 ( Thousands of dollars ) Revenues $ 508,364 $ 245,923 $ 232,191 $ 440,754 Operating income $ 116,073 $ 43,621 $ 30,892 $ 78,534 Net income $ 64,743 $ 20,300 $ 12,737 $ 42,315 Earnings per share Basic $ 1.23 $ 0.39 $ 0.24 $ 0.81 Diluted $ 1.22 $ 0.38 $ 0.24 $ 0.80 |
SUMMARY OF SIGNIFICANT ACCOUN33
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) $ in Thousands, number in Millions | 12 Months Ended | ||
Dec. 31, 2017USD ($) | Dec. 31, 2016USD ($) | Dec. 31, 2015USD ($) | |
Significant Accounting Policies [Line Items] | |||
Impact of reclassification upon adoption of ASU 2017-07 | $ 17,300 | $ 19,800 | |
Proceeds and Excess Tax Benefit from Share-based Compensation | 5,200 | ||
Operating Loss Carryforwards, Tax Benefit | 11,000 | ||
Unbilled Receivables, Current | $ 138,500 | 143,200 | |
Number of natural gas distribution services customers | 2 | ||
Allowance for Doubtful Accounts Receivable, Current | $ 4,800 | 4,200 | |
Goodwill, Impairment Loss | 0 | 0 | $ 0 |
Asset Impairment Charges | 0 | 0 | $ 0 |
Deferred Tax Assets, Valuation Allowance | 0 | 0 | |
Liability for Uncertainty in Income Taxes, Current | $ 0 | $ 0 | |
Segment Reporting, Disclosure of Major Customers | 0 | 0 | 0 |
Prior Period Reclassification Adjustment | $ 9,000 | $ 13,700 |
CREDIT FACILITY AND SHORT-TER34
CREDIT FACILITY AND SHORT-TERM NOTES PAYABLE (Details) $ in Thousands | 12 Months Ended | |
Dec. 31, 2017USD ($) | Dec. 31, 2016USD ($) | |
Line of Credit Facility [Line Items] | ||
Ratio of Indebtedness to Net Capital | 0.44 | |
Commercial paper maximum borrowing capacity | $ 700,000 | |
Commercial Paper | 357,215 | $ 145,000 |
Letters of Credit Outstanding, Amount | 2,100 | |
Short-term Debt | 0 | |
Line of Credit Facility, Remaining Borrowing Capacity | $ 340,700 | |
Short-term Debt, Weighted Average Interest Rate | 1.55% | 0.95% |
Line of Credit Facility, Expiration Date | Oct. 1, 2022 | |
Line of Credit [Member] | ||
Line of Credit Facility [Line Items] | ||
Debt Instrument, Covenant Description | The ONE Gas Credit Agreement contains certain financial, operational and legal covenants. Among other things, these covenants include maintaining ONE Gas’ total debt-to-capital ratio of no more than 70 percent at the end of any calendar quarter. The ONE Gas Credit Agreement also contains customary affirmative and negative covenants, including covenants relating to liens, indebtedness of subsidiaries, investments, changes in the nature of business, fundamental changes, transactions with affiliates, burdensome agreements, and use of proceeds. In the event of a breach of certain covenants by ONE Gas, amounts outstanding under the ONE Gas Credit Agreement may become due and payable immediately. | |
Line of Credit Facility Sublimit | $ 20,000 | |
Swingline subfacility | 60,000 | |
Line of Credit Facility Option to Increase Borrowing Capacity | 500,000 | |
Line of Credit Facility, Maximum Borrowing Capacity | $ 700,000 | |
Line of Credit Facility, Interest Rate Description | Borrowings, if any, will accrue interest at LIBOR plus 79.5 basis points. | |
Line of Credit Facility, Commitment Fee Description | The annual facility fee is 8 basis points. |
LONG-TERM DEBT (Details)
LONG-TERM DEBT (Details) $ in Millions | 12 Months Ended |
Dec. 31, 2017USD ($) | |
Note Payable Due 2019 [Member] | |
Debt Instrument [Line Items] | |
Debt Instrument, Covenant Description | The indenture governing our Senior Notes includes an event of default upon the acceleration of other indebtedness of $100 million or more. Such events of default would entitle the trustee or the holders of 25 percent in the aggregate principal amount of the outstanding Senior Notes to declare those senior notes immediately due and payable in full. |
Long-term Debt, Gross | $ 300 |
Debt Instrument, Interest Rate, Stated Percentage | 2.07% |
Debt Instrument, Call Feature | We may redeem our Senior Notes at par, plus accrued and unpaid interest to the redemption date, starting one month, three months, and six months, respectively, before their maturity dates. Prior to these dates, we may redeem these Senior Notes, in whole or in part, at a redemption price equal to the principal amount, plus accrued and unpaid interest and a make-whole premium. The redemption price will never be less than 100 percent of the principal amount of the respective note plus accrued and unpaid interest to the redemption date. Our Senior Notes are senior unsecured obligations, ranking equally in right of payment with all of our existing and future unsecured senior indebtedness. |
Note Payable Due 2024 [Member] | |
Debt Instrument [Line Items] | |
Debt Instrument, Covenant Description | The indenture governing our Senior Notes includes an event of default upon the acceleration of other indebtedness of $100 million or more. Such events of default would entitle the trustee or the holders of 25 percent in the aggregate principal amount of the outstanding Senior Notes to declare those senior notes immediately due and payable in full. |
Long-term Debt, Gross | $ 300 |
Debt Instrument, Interest Rate, Stated Percentage | 3.61% |
Debt Instrument, Call Feature | We may redeem our Senior Notes at par, plus accrued and unpaid interest to the redemption date, starting one month, three months, and six months, respectively, before their maturity dates. Prior to these dates, we may redeem these Senior Notes, in whole or in part, at a redemption price equal to the principal amount, plus accrued and unpaid interest and a make-whole premium. The redemption price will never be less than 100 percent of the principal amount of the respective note plus accrued and unpaid interest to the redemption date. Our Senior Notes are senior unsecured obligations, ranking equally in right of payment with all of our existing and future unsecured senior indebtedness. |
Notes Payable Due 2044 [Member] | |
Debt Instrument [Line Items] | |
Debt Instrument, Covenant Description | The indenture governing our Senior Notes includes an event of default upon the acceleration of other indebtedness of $100 million or more. Such events of default would entitle the trustee or the holders of 25 percent in the aggregate principal amount of the outstanding Senior Notes to declare those senior notes immediately due and payable in full. |
Long-term Debt, Gross | $ 600 |
Debt Instrument, Interest Rate, Stated Percentage | 4.658% |
Debt Instrument, Call Feature | We may redeem our Senior Notes at par, plus accrued and unpaid interest to the redemption date, starting one month, three months, and six months, respectively, before their maturity dates. Prior to these dates, we may redeem these Senior Notes, in whole or in part, at a redemption price equal to the principal amount, plus accrued and unpaid interest and a make-whole premium. The redemption price will never be less than 100 percent of the principal amount of the respective note plus accrued and unpaid interest to the redemption date. Our Senior Notes are senior unsecured obligations, ranking equally in right of payment with all of our existing and future unsecured senior indebtedness. |
EQUITY (Details)
EQUITY (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions | 3 Months Ended | 12 Months Ended | ||
Mar. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Dividends declared per share of stock | $ 1.68 | $ 1.40 | $ 1.20 | |
Preferred Stock, Shares Authorized | 50 | |||
Preferred Stock, Par or Stated Value Per Share | $ 0.01 | |||
Common stock authorized and available for issuance | 197.7 | |||
Stock Repurchase Program, Authorized Amount | $ 20 | |||
Common Stock, Dividends, Declared, Annualized Basis | $ 1.68 | $ 1.40 | $ 1.20 | |
Dividend Declared [Member] | ||||
Common Stock, Dividends, Per Share, Declared | $ 0.46 | |||
Common Stock, Dividends, Declared, Annualized Basis | $ 1.84 |
ACCUMULATED OTHER COMPREHENSI37
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Accumulated Other Comprehensive Income (Loss) [Line Items] | |||
Pension and other postretirement benefit plans, Tax | $ 808 | $ 486 | |
Accumulated Other Comprehensive Income (Loss), beginning balance | (4,715) | (4,401) | |
Pension and other postretirement benefit plans obligations [Abstract] | |||
Other comprehensive income (loss), before reclassification, net of tax | (1,293) | (776) | |
Amounts reclassified from accumulated other comprehensive income (loss), net of tax | 515 | 462 | |
Other comprehensive income (loss), net of tax | (778) | (314) | $ 773 |
Accumulated Other Comprehensive Income (Loss), ending balance | (5,493) | (4,715) | (4,401) |
Pension and other postretirement benefit plans obligations [Abstract] | |||
Amortization of net loss | 42,591 | 40,912 | 47,494 |
Amortization of unrecognized prior service cost | (4,597) | (3,316) | (1,962) |
Other comprehensive income (loss) reclassification adjustment, before tax and regulatory adjustments | 37,994 | 37,596 | 45,532 |
Other comprehensive income (loss) reclassification - regulatory adjustments | (37,157) | (36,845) | (44,615) |
Other comprehensive income (loss) reclassification adjustment, before tax | 837 | 751 | 917 |
Other comprehensive income (loss) reclassification adjustment, Tax | (322) | (289) | (353) |
Other comprehensive income (loss) reclassification adjustment, net of tax | $ 515 | $ 462 | $ 564 |
EARNINGS PER SHARE (Details)
EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ 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, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
EARNINGS PER SHARE OF COMMON STOCK, BASIC AND DILUTED [Line Items] | |||||||||||
Net income | $ 47,119 | $ 18,797 | $ 20,623 | $ 76,456 | $ 42,315 | $ 12,737 | $ 20,300 | $ 64,743 | $ 162,995 | $ 140,095 | $ 119,030 |
Weighted Average Number of Shares Outstanding, Basic | 52,527,000 | 52,453,000 | 52,578,000 | ||||||||
Earnings Per Share, Basic | $ 0.90 | $ 0.36 | $ 0.39 | $ 1.45 | $ 0.81 | $ 0.24 | $ 0.39 | $ 1.23 | $ 3.10 | $ 2.67 | $ 2.26 |
Dilutive Securities, Effect on Basic Earnings Per Share | $ 0 | $ 0 | $ 0 | ||||||||
Weighted Average Number Diluted Shares Outstanding Adjustment | 452,000 | 510,000 | 676,000 | ||||||||
Net Income (Loss) Available to Common Stockholders, Diluted | $ 162,995 | $ 140,095 | $ 119,030 | ||||||||
Weighted Average Number of Shares Outstanding, Diluted | 52,979,000 | 52,963,000 | 53,254,000 | ||||||||
Earnings Per Share, Diluted | $ 0.89 | $ 0.36 | $ 0.39 | $ 1.44 | $ 0.80 | $ 0.24 | $ 0.38 | $ 1.22 | $ 3.08 | $ 2.65 | $ 2.24 |
Common Stock, Shares, Issued | 52,598,005 | 52,598,005 | 52,598,005 | 52,598,005 |
DERIVATIVE FINANCIAL INSTRUME39
DERIVATIVE FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS (Details) | 12 Months Ended | |
Dec. 31, 2017USD ($)MMcf | Dec. 31, 2016USD ($)MMcf | |
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items] | ||
Derivative, Nonmonetary Notional Amount | MMcf | 14,100 | 14,300 |
Premiums recorded in other current assets on natural gas contracts held | $ 5,500,000 | $ 5,400,000 |
Fair Value Assets, Transfers between Levels | 0 | 0 |
Long-term Debt | 1,200,000,000 | 1,200,000,000 |
Fair Value, Inputs, Level 1 [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items] | ||
Fair value of natural gas call options held | 1,100,000 | 6,500,000 |
Fair Value, Inputs, Level 2 [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items] | ||
Long-term Debt, Fair Value | $ 1,300,000,000 | $ 1,200,000,000 |
REGULATORY ASSETS AND LIABILI40
REGULATORY ASSETS AND LIABILITIES (Details) - USD ($) $ in Thousands | 12 Months Ended | ||||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Jan. 01, 2017 | Jan. 31, 2016 | |
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items] | |||||
Regulatory Assets, Current | $ 88,180 | $ 83,146 | |||
Regulatory Assets, Noncurrent | 405,189 | 440,522 | |||
Regulatory Liability, Noncurrent | (519,421) | 0 | |||
Net regulatory assets and liabilities, current | 78,742 | 71,224 | |||
Net regulatory assets and liabilities, noncurrent | (114,232) | 440,522 | |||
Net Regulatory Assets | (35,490) | 511,746 | |||
Amortization of Rate Deferral | $ 1,000 | $ 3,800 | $ 1,600 | ||
Federal income tax rate changes [Member] | |||||
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items] | |||||
Regulatory Asset, Amortization Period | See Note 12 | ||||
Regulatory Liability, Current | $ 0 | ||||
Regulatory Liability, Noncurrent | (519,421) | ||||
Regulatory Liabilities | $ (519,421) | ||||
Weather normalization [Member] | |||||
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items] | |||||
Regulatory Asset, Amortization Period | 1 year | 1 year | |||
Regulatory Assets, Current | $ 17,461 | $ 17,661 | |||
Regulatory Assets, Noncurrent | 0 | 0 | |||
Regulatory Assets | $ 17,461 | $ 17,661 | |||
Over-recovered purchased-gas costs [Member] | |||||
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items] | |||||
Regulatory Asset, Amortization Period | 1 year | 1 year | |||
Regulatory Liability, Current | $ (9,434) | $ (10,154) | |||
Regulatory Liability, Noncurrent | 0 | 0 | |||
Regulatory Liabilities | $ (9,434) | $ (10,154) | |||
Ad valorem tax [Member] | |||||
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items] | |||||
Regulatory Asset, Amortization Period | 1 year | 1 year | |||
Regulatory Liability, Current | $ (4) | $ (1,768) | |||
Regulatory Liability, Noncurrent | 0 | 0 | |||
Regulatory Liabilities | (4) | (1,768) | |||
Total regulated liabilities [Member] | |||||
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items] | |||||
Regulatory Liability, Current | (9,438) | (11,922) | |||
Regulatory Liability, Noncurrent | (519,421) | 0 | |||
Regulatory Liabilities | $ (528,859) | $ (11,922) | |||
Under-recovered purchased-gas costs [Member] | |||||
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items] | |||||
Regulatory Asset, Amortization Period | 1 year | 1 year | |||
Regulatory Assets, Current | $ 41,238 | $ 29,901 | |||
Regulatory Assets, Noncurrent | 0 | 0 | |||
Regulatory Assets | $ 41,238 | $ 29,901 | |||
Pension and postretirement benefit costs [Member] | |||||
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items] | |||||
Regulatory Asset, Amortization Period | See Note 11 | See Note 11 | |||
Regulatory Assets, Current | $ 25,156 | $ 31,498 | |||
Regulatory Assets, Noncurrent | 387,582 | 427,448 | |||
Regulatory Assets | $ 412,738 | $ 458,946 | |||
Reacquired debt costs [Member] | |||||
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items] | |||||
Regulatory Asset, Amortization Period | 10 years | 11 years | |||
Regulatory Assets, Current | $ 812 | $ 812 | |||
Regulatory Assets, Noncurrent | 7,298 | 8,108 | |||
Regulatory Assets | $ 8,110 | $ 8,920 | |||
MGP Costs [Member] | |||||
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items] | |||||
Regulatory Asset, Amortization Period | 15 years | ||||
Regulatory Assets, Current | $ 0 | ||||
Regulatory Assets, Noncurrent | 6,104 | $ 5,900 | |||
Regulatory Assets | $ 6,104 | ||||
Other regulatory assets [Member] | |||||
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items] | |||||
Regulatory Asset, Amortization Period | 1 to 21 years | 1 to 22 years | |||
Regulatory Assets, Current | $ 3,513 | $ 3,274 | |||
Regulatory Assets, Noncurrent | 4,205 | 4,966 | |||
Regulatory Assets | 7,718 | 8,240 | |||
Total regulatory assets, net of amortization [Member] | |||||
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items] | |||||
Regulatory Assets, Current | 88,180 | 83,146 | |||
Regulatory Assets, Noncurrent | 405,189 | 440,522 | |||
Regulatory Assets | $ 493,369 | $ 523,668 | |||
Information Technology Costs [Member] | |||||
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items] | |||||
Regulatory Asset, Amortization Period | 4 | ||||
Regulatory Assets, Noncurrent | $ 2,400 |
PROPERTY, PLANT AND EQUIPMENT41
PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Property, Plant and Equipment [Line Items] | |||
Property, plant and equipment | $ 5,713,912 | $ 5,404,168 | |
Accumulated depreciation and amortization | (1,706,327) | (1,672,548) | |
Net property, plant and equipment | 4,007,585 | 3,731,620 | |
Regulated [Member] | |||
Property, Plant and Equipment [Line Items] | |||
Property, plant and equipment | 5,713,912 | 5,404,168 | |
Accumulated depreciation and amortization | (1,706,327) | (1,672,548) | |
Net property, plant and equipment | $ 4,007,585 | $ 3,731,620 | |
Average depreciation rates, minimum | 2.00% | 2.00% | 2.00% |
Average depreciation rates, maximum | 3.00% | 3.00% | 3.00% |
Interest costs capitalized | $ 3,000 | $ 3,600 | $ 2,600 |
Construction work in process expenditures incurred but not yet paid | 21,700 | 11,900 | $ 15,000 |
Natural gas distribution pipelines and related equipment | Regulated [Member] | |||
Property, Plant and Equipment [Line Items] | |||
Property, plant and equipment | 4,572,343 | 4,321,429 | |
Natural gas transmission pipelines and related equipment | Regulated [Member] | |||
Property, Plant and Equipment [Line Items] | |||
Property, plant and equipment | 497,791 | 481,953 | |
General plant and other | Regulated [Member] | |||
Property, Plant and Equipment [Line Items] | |||
Property, plant and equipment | 513,445 | 530,459 | |
Construction work in process | Regulated [Member] | |||
Property, Plant and Equipment [Line Items] | |||
Property, plant and equipment | $ 130,333 | $ 70,327 |
SHARE-BASED PAYMENTS (Details)
SHARE-BASED PAYMENTS (Details) - USD ($) $ / shares in Units, $ in Thousands | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Share-based Payments [Line Items] | |||
Common Stock, Capital Shares Reserved for Future Issuance | 2,800,000 | ||
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant | 500,000 | ||
Share-based compensation expense, net of tax | $ 4,900 | $ 7,000 | $ 5,700 |
Share-based compensation, tax benefit | $ 3,000 | 4,300 | 3,500 |
Shares remaining under ESAP | 1,812 | ||
Share-based compensation expense | $ 8,876 | 11,219 | $ 9,187 |
Employee Stock Purchase Plan [Member] | |||
Share-based Payments [Line Items] | |||
Description | Subject to certain exclusions, all employees who work at least 20 hours per week are eligible to participate in the ESPP. Employees can choose to have up to 10 percent of their annual base pay withheld to purchase our common stock, subject to terms and limitations of the plan. The purchase price of the stock is 85 percent of the lower of the average market price of our common stock on the grant date or exercise date. | ||
Employee Stock Award Program [Member] | |||
Share-based Payments [Line Items] | |||
Description | Under the program, each time the per-share closing price of our common stock on the NYSE closed for the first time at or above each $1.00 increment above its previous historical high closing price, we issued, for no monetary consideration, one share of our common stock to all eligible employees. | ||
Restricted Stock Units (RSUs) [Member] | |||
Share-based Payments [Line Items] | |||
Award vesting period | 3 years | ||
Forfeiture rate maximum (in hundredths) | 3.00% | ||
Total compensation cost not yet recognized | $ 2,600 | ||
Total compensation cost not yet recognized, period for recognition | 1 year 8 months 15 days | ||
Fair value of vested shares | $ 5,500 | $ 4,500 | |
Nonvested beginning balance (in units) | 194,900 | ||
Nonvested beginning balance (in dollars per unit) | $ 41.68 | ||
Granted (in units) | 37,825 | ||
Weighted -average grant date fair value (per unit) | $ 63.97 | $ 58.30 | $ 41.40 |
Vested (in units) | (85,490) | ||
Vested (in dollars per unit) | $ 33.76 | ||
Forfeited (in units) | (6,570) | ||
Forfeited (in dollars per unit) | $ 52.65 | ||
Nonvested ending balance (in units) | 140,665 | 194,900 | |
Nonvested ending balance (in dollars per unit) | $ 51.97 | $ 41.68 | |
Fair value of shares granted (thousands of dollars) | $ 2,420 | $ 2,503 | $ 3,141 |
Performance Unit Awards [Member] | |||
Share-based Payments [Line Items] | |||
Award vesting period | 3 years | ||
Forfeiture rate maximum (in hundredths) | 3.00% | ||
Total compensation cost not yet recognized | $ 5,100 | ||
Total compensation cost not yet recognized, period for recognition | 1 year 8 months 15 days | ||
Fair value of vested shares | $ 15,600 | $ 19,500 | |
Nonvested beginning balance (in units) | 288,811 | ||
Nonvested beginning balance (in dollars per unit) | $ 46.06 | ||
Granted (in units) | 74,120 | ||
Weighted -average grant date fair value (per unit) | $ 68.94 | $ 64.06 | $ 44.48 |
Vested (in units) | (117,626) | ||
Vested (in dollars per unit) | $ 35.98 | ||
Forfeited (in units) | (7,981) | ||
Forfeited (in dollars per unit) | $ 58.58 | ||
Nonvested ending balance (in units) | 237,324 | 288,811 | |
Nonvested ending balance (in dollars per unit) | $ 57.78 | $ 46.06 | |
Fair value of shares granted (thousands of dollars) | $ 5,110 | $ 4,766 | $ 4,486 |
Expected volatility rate | 20.70% | 18.20% | 15.90% |
Expected dividend yield | 2.63% | 2.40% | 2.90% |
Risk-free interest rate | 1.48% | 0.91% | 1.10% |
Description | Upon vesting, a holder of performance stock units is entitled to receive a number of shares of common stock equal to a percentage (0 percent to 200 percent) of the performance stock units granted, based on our total shareholder return over the vesting period, compared with the total shareholder return of a peer group of other utilities over the same period. | ||
Employee Stock Purchase Plan [Member] | |||
Share-based Payments [Line Items] | |||
Common Stock, Capital Shares Reserved for Future Issuance | 700,000 | ||
Maximum allowable percentage of annual base pay withheld to purchase common stock | 10.00% | ||
Purchase price percentage of the lower of its grant date or exercise date market price (in hundredths) | 85.00% | ||
Percent of employees who participated in the Employee Stock Purchase Plan | 43.00% | 41.00% | 40.00% |
Shares sold under employee stock purchase plan | 78,472 | 83,431 | 51,092 |
Share price of shares sold under Employee Stock Purchase Plan in dollars per share | $ 56.80 | $ 54.51 | $ 36.15 |
Employee Stock Purchase Plan Compensation Expense | $ 1,200 | $ 1,400 | $ 1,300 |
Employee Stock Award Program [Member] | |||
Share-based Payments [Line Items] | |||
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized | 125,000 | ||
Shares issued to employees under the Employee Stock Award Program | 13,791 | 50,573 | 23,506 |
Share-based compensation expense | $ 900 | $ 3,000 | $ 1,100 |
EMPLOYEE BENEFIT PLANS (Details
EMPLOYEE BENEFIT PLANS (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended | |||||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Sep. 30, 2016 | Sep. 30, 2015 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Defined Benefit Plans and Other Postemployment Benefit Plans Table Text Block [Line Items] | ||||||||
Defined Benefit Plan Assumptions Used To Determine Benefit Obligations Rate of Compensation Increase, Minimum | 3.25% | 3.25% | 3.25% | 3.25% | ||||
Defined Benefit Plan Assumptions Used To Determine Benefit Obligations Rate of Compensation Increase, Maximum | 3.35% | 3.40% | 3.35% | 3.40% | ||||
Compensation increase rate - minimum | 3.25% | 3.35% | 3.30% | |||||
Compensation increase rate- maximum | 3.40% | 3.40% | 3.50% | |||||
Description of basis used to determine overall expected long-term rate of return on plan assets | We determine our overall expected long-term rate of return on plan assets, based on our review of historical returns and economic growth models. As of December 31, 2014, we updated our assumed mortality rates to incorporate the new set of mortality tables issued by the Society of Actuaries in October 2014. We determine our discount rates annually. We estimate our discount rate based upon a comparison of the expected cash flows associated with our future payments under our defined benefit pension and other postemployment obligations to a hypothetical bond portfolio created using high-quality bonds that closely match expected cash flows. Bond portfolios are developed by selecting a bond for each of the next 60 years based on the maturity dates of the bonds. Bonds selected to be included in the portfolios are only those rated by Moody’s as AA- or better and exclude callable bonds, bonds with less than a minimum issue size, yield outliers and other filtering criteria to remove unsuitable bonds. | |||||||
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] | ||||||||
Benefits paid | $ (18,100) | $ (46,700) | $ (35,700) | |||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Benefits paid | (18,100) | (46,700) | (35,700) | |||||
Noncurrent liabilities | (172,938) | $ (303,507) | (172,938) | (303,507) | ||||
Benefits paid | $ (18,100) | $ (46,700) | (35,700) | |||||
Assets expected to be withdrawn or returned | 0 | |||||||
Amortization of unrecognized prior service cost | $ (4,597) | (3,316) | $ (1,962) | |||||
Amortization of loss | 42,591 | 40,912 | 47,494 | |||||
Total recognized in other comprehensive income (loss) | (778) | $ (314) | 773 | |||||
Amount recognized in other comprehensive income | $ 0 | |||||||
Health care cost-trend rate assumed for next year | 7.00% | 7.25% | ||||||
Rate to which the cost-trend rate is assumed to decline (the ultimate trend rate) | 5.00% | 5.00% | ||||||
Year that the rate reaches the ultimate trend rate | 2,023 | 2,022 | 2,023 | 2,022 | ||||
Target asset allocation | 100.00% | |||||||
US Large-Cap Equity [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Target asset allocation | 18.00% | |||||||
Investment-grade bonds [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Target asset allocation | 40.00% | |||||||
Developed foreign large-cap equities [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Target asset allocation | 10.00% | |||||||
Alternative investments [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Target asset allocation | 14.00% | |||||||
Mid-cap equities [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Target asset allocation | 7.00% | |||||||
Emerging market equities [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Target asset allocation | 6.00% | |||||||
Small-cap equities [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Target asset allocation | 5.00% | |||||||
Equity Securities [Member] | ||||||||
Defined Benefit Plans and Other Postemployment Benefit Plans Table Text Block [Line Items] | ||||||||
Defined Benefit Plan, Target Allocation Percentage | 0.7 | |||||||
Fixed Income Funds [Member] | ||||||||
Defined Benefit Plans and Other Postemployment Benefit Plans Table Text Block [Line Items] | ||||||||
Defined Benefit Plan, Target Allocation Percentage | 0.3 | |||||||
Pension Plan [Member] | ||||||||
Defined Benefit Plans and Other Postemployment Benefit Plans Table Text Block [Line Items] | ||||||||
Net periodic benefit cost | $ 30,240 | $ 31,965 | $ 37,952 | |||||
Plan amendment | $ 0 | $ 0 | ||||||
Discount rate | 3.80% | 4.30% | 3.80% | 4.30% | ||||
Weighted average discount rate | 4.75% | 4.25% | 4.30% | 4.75% | ||||
Expected long-term return on plan assets | 7.75% | 7.75% | 7.75% | |||||
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] | ||||||||
Benefit obligation, beginning of period | $ 985,624 | $ 966,531 | $ 985,624 | |||||
Service cost | 12,176 | 12,055 | $ 13,660 | |||||
Interest cost | 40,453 | 45,550 | 43,542 | |||||
Plan participants' contributions | 0 | 0 | ||||||
Actuarial loss (gain) | 76,325 | 25,886 | ||||||
Plan amendment | 0 | 0 | ||||||
Benefits paid | (55,107) | (71,066) | ||||||
Settlements | (46,487) | 31,518 | ||||||
Benefit obligation, end of period | $ 993,891 | $ 966,531 | $ 985,624 | 993,891 | 966,531 | 985,624 | ||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Actual return on plan assets | 135,056 | 48,768 | ||||||
Employer contributions | 111,936 | 12,441 | ||||||
Plan participants' contributions | 0 | 0 | ||||||
Benefits paid | (55,107) | (71,066) | ||||||
Settlements | (46,667) | (35,718) | ||||||
Fair value of plan assets, end of period | 884,804 | 739,586 | 785,161 | 884,804 | 739,586 | 785,161 | ||
Balance at December 31 | (109,087) | (226,945) | (109,087) | (226,945) | ||||
Current liabilities | (963) | (941) | (963) | (941) | ||||
Noncurrent liabilities | (108,124) | (226,004) | (108,124) | (226,004) | ||||
Balance at December 31 | (109,087) | (226,945) | (109,087) | (226,945) | ||||
Benefits paid | (55,107) | (71,066) | ||||||
Accumulated benefit obligation | 936,700 | 912,400 | 936,700 | 912,400 | ||||
Service cost | 12,176 | 12,055 | 13,660 | |||||
Interest cost | 40,453 | 45,550 | 43,542 | |||||
Expected return on assets | (58,496) | (61,183) | (61,769) | |||||
Amortization of unrecognized prior service cost | 0 | 0 | 266 | |||||
Amortization of loss | 36,107 | 35,543 | 42,226 | |||||
Settlements | 0 | 0 | 27 | |||||
Net periodic benefit cost | 30,240 | 31,965 | 37,952 | |||||
Net loss arising during the period | (2,101) | (1,262) | 339 | |||||
Amortization of loss | 837 | 751 | 917 | |||||
Deferred income taxes | 486 | 197 | (483) | |||||
Total recognized in other comprehensive income (loss) | 778 | 314 | (773) | |||||
Prior service credit (cost) | 0 | 0 | 0 | 0 | ||||
Accumulated loss | (378,595) | (414,757) | (378,595) | (414,757) | ||||
Accumulated other comprehensive loss before regulatory assets | (378,595) | (414,757) | (378,595) | (414,757) | ||||
Regulatory asset for regulated entities | 369,647 | 407,073 | 369,647 | 407,073 | ||||
Accumulated other comprehensive loss after regulatory assets | (8,948) | (7,684) | (8,948) | (7,684) | ||||
Deferred income taxes | 3,455 | 2,969 | 3,455 | 2,969 | ||||
Accumulated other comprehensive loss, net of tax | (5,493) | (4,715) | (5,493) | (4,715) | ||||
Prior service credit (cost) expected to be recognized in following fiscal year | 0 | 0 | ||||||
Actuarial net loss, to be recognized in 2017 | 39,913 | 39,913 | ||||||
Effect of a one percentage point change on total of service and interest cost - increase | 239 | |||||||
Effect of a one percentage point change on other postemployment benefit obligation - increase | 2,906 | |||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] | ||||||||
Level 3 fair value measurement, January 1 | 114,437 | 102,492 | 114,437 | |||||
Net realized and unrealized gains (losses) | 7,624 | 3,898 | ||||||
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases | 16,300 | |||||||
Settlements | (12,551) | (15,843) | ||||||
Level 3 fair value measurement, December 31 | 113,865 | 102,492 | 114,437 | 113,865 | 102,492 | 114,437 | ||
Employer contributions | 111,936 | 12,441 | ||||||
Expected employer contributions in 2017 | 1,000 | |||||||
2,017 | 50,875 | 50,875 | ||||||
2,018 | 51,635 | 51,635 | ||||||
2,019 | 52,518 | 52,518 | ||||||
2,020 | 53,516 | 53,516 | ||||||
2,021 | 54,289 | 54,289 | ||||||
2022 through 2027 | 286,188 | 286,188 | ||||||
Pension Plan [Member] | Equity Securities [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 392,925 | 430,642 | 392,925 | 430,642 | ||||
Pension Plan [Member] | Government Obligations [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 74,596 | 47,445 | 74,596 | 47,445 | ||||
Pension Plan [Member] | Corporate Obligations [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 260,907 | 129,036 | 260,907 | 129,036 | ||||
Pension Plan [Member] | Cash and Money Market Funds [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 41,926 | 29,900 | 41,926 | 29,900 | ||||
Pension Plan [Member] | Insurance contracts and group annuity contracts [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 35,158 | 45,140 | 35,158 | 45,140 | ||||
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] | ||||||||
Level 3 fair value measurement, January 1 | 56,465 | 45,140 | 56,465 | |||||
Net realized and unrealized gains (losses) | 2,569 | 4,518 | ||||||
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases | 0 | |||||||
Settlements | (12,551) | (15,843) | ||||||
Level 3 fair value measurement, December 31 | 35,158 | 45,140 | 56,465 | 35,158 | 45,140 | 56,465 | ||
Pension Plan [Member] | Other Investments [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 79,292 | 57,423 | 79,292 | 57,423 | ||||
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] | ||||||||
Level 3 fair value measurement, January 1 | $ 57,972 | 57,352 | 57,972 | |||||
Net realized and unrealized gains (losses) | 5,055 | (620) | ||||||
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases | 16,300 | |||||||
Settlements | 0 | 0 | ||||||
Level 3 fair value measurement, December 31 | 78,707 | 57,352 | $ 57,972 | 78,707 | 57,352 | 57,972 | ||
Pension Plan [Member] | Level 1 [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 323,050 | 385,441 | 323,050 | 385,441 | ||||
Pension Plan [Member] | Level 1 [Member] | Equity Securities [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 301,911 | 371,655 | 301,911 | 371,655 | ||||
Pension Plan [Member] | Level 1 [Member] | Government Obligations [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 0 | 0 | 0 | 0 | ||||
Pension Plan [Member] | Level 1 [Member] | Corporate Obligations [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 0 | 0 | 0 | 0 | ||||
Pension Plan [Member] | Level 1 [Member] | Cash and Money Market Funds [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 21,139 | 13,786 | 21,139 | 13,786 | ||||
Pension Plan [Member] | Level 1 [Member] | Insurance contracts and group annuity contracts [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 0 | 0 | 0 | 0 | ||||
Pension Plan [Member] | Level 1 [Member] | Other Investments [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 0 | 0 | 0 | 0 | ||||
Pension Plan [Member] | Level 2 [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 447,889 | 251,653 | 447,889 | 251,653 | ||||
Pension Plan [Member] | Level 2 [Member] | Equity Securities [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 91,014 | 58,987 | 91,014 | 58,987 | ||||
Pension Plan [Member] | Level 2 [Member] | Government Obligations [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 74,596 | 47,445 | 74,596 | 47,445 | ||||
Pension Plan [Member] | Level 2 [Member] | Corporate Obligations [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 260,907 | 129,036 | 260,907 | 129,036 | ||||
Pension Plan [Member] | Level 2 [Member] | Cash and Money Market Funds [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 20,787 | 16,114 | 20,787 | 16,114 | ||||
Pension Plan [Member] | Level 2 [Member] | Insurance contracts and group annuity contracts [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 0 | 0 | 0 | 0 | ||||
Pension Plan [Member] | Level 2 [Member] | Other Investments [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 585 | 71 | 585 | 71 | ||||
Pension Plan [Member] | Level 3 [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 113,865 | 102,492 | 113,865 | 102,492 | ||||
Pension Plan [Member] | Level 3 [Member] | Equity Securities [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 0 | 0 | 0 | 0 | ||||
Pension Plan [Member] | Level 3 [Member] | Government Obligations [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 0 | 0 | 0 | 0 | ||||
Pension Plan [Member] | Level 3 [Member] | Corporate Obligations [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 0 | 0 | 0 | 0 | ||||
Pension Plan [Member] | Level 3 [Member] | Cash and Money Market Funds [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | $ 0 | 0 | 0 | 0 | ||||
Pension Plan [Member] | Level 3 [Member] | Insurance contracts and group annuity contracts [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 45,140 | 45,140 | ||||||
Pension Plan [Member] | Level 3 [Member] | Other Investments [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | $ 57,352 | 57,352 | ||||||
Other Postretirement Benefit Plan [Member] | ||||||||
Defined Benefit Plans and Other Postemployment Benefit Plans Table Text Block [Line Items] | ||||||||
Net periodic benefit cost | $ 1,696 | 2,593 | $ 5,033 | |||||
Minimum number of years of service for certain employees to be eligible to participate in shared welfare plans that provide postemployment medical and life insurance benefits | 5 | |||||||
Plan amendment | $ 171 | $ (483) | ||||||
Discount rate | 3.70% | 4.20% | 3.70% | 4.20% | ||||
Weighted average discount rate | 3.75% | 4.75% | 4.75% | 4.25% | 4.20% | |||
Expected long-term return on plan assets | 7.75% | 8.00% | 7.60% | 7.75% | ||||
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] | ||||||||
Benefit obligation, beginning of period | $ 228,253 | $ 243,548 | $ 228,253 | |||||
Service cost | 2,509 | 2,675 | $ 3,257 | |||||
Interest cost | 9,890 | 10,235 | 10,628 | |||||
Plan participants' contributions | 3,483 | 3,043 | ||||||
Actuarial loss (gain) | 12,129 | 14,309 | ||||||
Plan amendment | 171 | (483) | ||||||
Benefits paid | (16,690) | (15,450) | ||||||
Settlements | 0 | 0 | ||||||
Benefit obligation, end of period | $ 255,040 | $ 243,548 | $ 228,253 | 255,040 | 243,548 | 228,253 | ||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Actual return on plan assets | 31,228 | 9,733 | ||||||
Employer contributions | 6,159 | 13,225 | ||||||
Plan participants' contributions | 3,483 | 3,043 | ||||||
Benefits paid | (16,690) | (15,450) | ||||||
Settlements | 0 | 0 | ||||||
Fair value of plan assets, end of period | 190,226 | 166,046 | $ 155,495 | 190,226 | 166,046 | 155,495 | ||
Balance at December 31 | (64,814) | (77,502) | (64,814) | (77,502) | ||||
Current liabilities | 0 | 0 | 0 | 0 | ||||
Noncurrent liabilities | (64,814) | (77,502) | (64,814) | (77,502) | ||||
Balance at December 31 | (64,814) | (77,502) | (64,814) | (77,502) | ||||
Benefits paid | (16,690) | (15,450) | ||||||
Service cost | 2,509 | 2,675 | 3,257 | |||||
Interest cost | 9,890 | 10,235 | 10,628 | |||||
Expected return on assets | (12,590) | (12,370) | (11,892) | |||||
Amortization of unrecognized prior service cost | (4,597) | (3,316) | (2,228) | |||||
Amortization of loss | 6,484 | 5,369 | 5,268 | |||||
Net periodic benefit cost | 1,696 | 2,593 | 5,033 | |||||
Amortization of loss | 0 | |||||||
Prior service credit (cost) | 5,442 | 10,211 | 5,442 | 10,211 | ||||
Accumulated loss | (49,030) | (62,084) | (49,030) | (62,084) | ||||
Accumulated other comprehensive loss before regulatory assets | (43,588) | (51,873) | (43,588) | (51,873) | ||||
Regulatory asset for regulated entities | 43,588 | 51,873 | 43,588 | 51,873 | ||||
Accumulated other comprehensive loss after regulatory assets | 0 | 0 | 0 | 0 | ||||
Deferred income taxes | 0 | 0 | 0 | 0 | ||||
Accumulated other comprehensive loss, net of tax | 0 | 0 | 0 | 0 | ||||
Prior service credit (cost) expected to be recognized in following fiscal year | (4,567) | (4,567) | ||||||
Actuarial net loss, to be recognized in 2017 | 3,887 | 3,887 | ||||||
Effect of a one percentage point change on total of service and interest cost - decrease | (238) | |||||||
Effect of a one percentage point change on other postemployment benefit obligation - decrease | (3,006) | |||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] | ||||||||
Employer contributions | 6,159 | 13,225 | ||||||
Expected employer contributions in 2017 | 3,000 | |||||||
2,017 | 17,293 | 17,293 | ||||||
2,018 | 17,383 | 17,383 | ||||||
2,019 | 17,538 | 17,538 | ||||||
2,020 | 17,485 | 17,485 | ||||||
2,021 | 17,558 | 17,558 | ||||||
2022 through 2027 | 85,543 | 85,543 | ||||||
Other Postretirement Benefit Plan [Member] | Equity Securities [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 63,303 | 47,140 | 63,303 | 47,140 | ||||
Other Postretirement Benefit Plan [Member] | Government Obligations [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 101 | 75 | 101 | 75 | ||||
Other Postretirement Benefit Plan [Member] | Corporate Obligations [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 25,905 | 19,948 | 25,905 | 19,948 | ||||
Other Postretirement Benefit Plan [Member] | Cash and Money Market Funds [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 4,540 | 17,063 | 4,540 | 17,063 | ||||
Other Postretirement Benefit Plan [Member] | Insurance contracts and group annuity contracts [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 96,377 | 81,820 | 96,377 | 81,820 | ||||
Other Postretirement Benefit Plan [Member] | Level 1 [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 67,692 | 39,891 | 67,692 | 39,891 | ||||
Other Postretirement Benefit Plan [Member] | Level 1 [Member] | Equity Securities [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 63,180 | 39,817 | 63,180 | 39,817 | ||||
Other Postretirement Benefit Plan [Member] | Level 1 [Member] | Government Obligations [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 0 | 0 | 0 | 0 | ||||
Other Postretirement Benefit Plan [Member] | Level 1 [Member] | Corporate Obligations [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 0 | 0 | 0 | 0 | ||||
Other Postretirement Benefit Plan [Member] | Level 1 [Member] | Cash and Money Market Funds [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 4,512 | 74 | 4,512 | 74 | ||||
Other Postretirement Benefit Plan [Member] | Level 1 [Member] | Insurance contracts and group annuity contracts [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 0 | 0 | 0 | 0 | ||||
Other Postretirement Benefit Plan [Member] | Level 2 [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 122,534 | 126,155 | 122,534 | 126,155 | ||||
Other Postretirement Benefit Plan [Member] | Level 2 [Member] | Equity Securities [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 123 | 7,323 | 123 | 7,323 | ||||
Other Postretirement Benefit Plan [Member] | Level 2 [Member] | Government Obligations [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 101 | 75 | 101 | 75 | ||||
Other Postretirement Benefit Plan [Member] | Level 2 [Member] | Corporate Obligations [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 25,905 | 19,948 | 25,905 | 19,948 | ||||
Other Postretirement Benefit Plan [Member] | Level 2 [Member] | Cash and Money Market Funds [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 28 | 16,989 | 28 | 16,989 | ||||
Other Postretirement Benefit Plan [Member] | Level 2 [Member] | Insurance contracts and group annuity contracts [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 96,377 | 81,820 | 96,377 | 81,820 | ||||
Other Postretirement Benefit Plan [Member] | Level 3 [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 0 | 0 | 0 | 0 | ||||
Other Postretirement Benefit Plan [Member] | Level 3 [Member] | Equity Securities [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 0 | 0 | 0 | 0 | ||||
Other Postretirement Benefit Plan [Member] | Level 3 [Member] | Government Obligations [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 0 | 0 | 0 | 0 | ||||
Other Postretirement Benefit Plan [Member] | Level 3 [Member] | Corporate Obligations [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 0 | 0 | 0 | 0 | ||||
Other Postretirement Benefit Plan [Member] | Level 3 [Member] | Cash and Money Market Funds [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | 0 | 0 | 0 | 0 | ||||
Other Postretirement Benefit Plan [Member] | Level 3 [Member] | Insurance contracts and group annuity contracts [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||||||||
Fair value of plan assets, end of period | $ 0 | $ 0 | $ 0 | 0 | ||||
ONE Gas 401(k) Plan [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] | ||||||||
Percent of employee contributions matched of eligible compensation (in hundredths) | 100.00% | |||||||
Maximum percentage of each participants eligible compensation subject to certain limits matching (in hundredths) | 6.00% | |||||||
Contributions made to 401(k) plan | $ 11,700 | 10,800 | 10,200 | |||||
ONE Gas Profit-Sharing Plan [Member] | ||||||||
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] | ||||||||
Profit sharing contribution percentage | 1.00% | |||||||
Contributions made to profit-sharing plan | $ 8,100 | $ 6,000 | $ 6,500 |
INCOME TAXES (Details)
INCOME TAXES (Details) - USD ($) | 12 Months Ended | |||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Decrease in net deferred tax liability due to enacted tax rate changes | $ 517,200,000 | |||
Deferred tax expense, remeasured deferred taxes | 2,200,000 | |||
Impact to cash flows attributable to adjustments to net deferred tax liability for enacted tax rate changes | 0 | |||
Deferred Tax Assets, Operating Loss Carryforwards, Domestic | 96,900,000 | |||
Operating Loss Carryforwards, Tax Benefit | 11,000,000 | |||
Deferred Tax Assets, Operating Loss Carryforwards, State and Local | 96,600,000 | |||
Current income tax provision (benefit) | ||||
Federal | 0 | $ (2,016,000) | $ 7,135,000 | |
State | 750,000 | 471,000 | 2,055,000 | |
Total current income tax provision (benefit) | 750,000 | (1,545,000) | 9,190,000 | |
Deferred income tax provision | ||||
Federal | 83,138,000 | 76,247,000 | 56,440,000 | |
State | 9,255,000 | 10,541,000 | 7,349,000 | |
Total deferred income tax provision | 92,393,000 | 86,788,000 | 63,789,000 | |
Income Tax Reconciliation [Abstract] | ||||
Income before income taxes | $ 256,138,000 | $ 225,338,000 | $ 192,009,000 | |
Federal statutory income tax rate | 35.00% | 35.00% | 35.00% | |
Provision for federal income taxes | $ 89,648,000 | $ 78,868,000 | $ 67,203,000 | |
State income taxes, net of federal benefit | 6,503,000 | 7,158,000 | 6,114,000 | |
Effective Income Tax Rate Reconciliation, nonregulated deferred tax rate decrease | 2,162,000 | 0 | 0 | |
Effective Income Tax Rate Reconciliation, tax benefit of employee share based compensation | (5,162,000) | 0 | 0 | |
Other, net | (8,000) | (783,000) | (338,000) | |
Income tax provision | 93,143,000 | 85,243,000 | $ 72,979,000 | |
Deferred tax assets | ||||
Deferred tax assets, employee benefits and other accrued liabilities | 40,277,000 | 123,333,000 | ||
Deferred tax asset, regulatory adjustments | 129,421,000 | 0 | ||
Net operating loss | 24,712,000 | 23,094,000 | ||
Other | 2,984,000 | 5,716,000 | ||
Total deferred tax assets | 197,394,000 | 152,143,000 | ||
Deferred tax liabilities | ||||
Excess of tax over book depreciation | 677,249,000 | 990,682,000 | ||
Purchased-gas cost adjustment | 13,805,000 | 13,822,000 | ||
Other regulatory assets and liabilities, net | 106,285,000 | 186,207,000 | ||
Total deferred tax liabilities | 797,339,000 | 1,190,711,000 | ||
Net deferred tax liabilities | $ 599,945,000 | $ 1,038,568,000 | ||
Tax Period [Domain] | ||||
Income Tax Reconciliation [Abstract] | ||||
Federal statutory income tax rate | 21.00% | |||
Deferred tax liabilities | ||||
NOL Limitation | 80.00% | |||
Minimum [Member] | ||||
Operating Loss Carryforwards, Expiration Date | Dec. 31, 2025 | |||
Maximum [Member] | ||||
Operating Loss Carryforwards, Expiration Date | Dec. 31, 2037 |
COMMITMENTS AND CONTINGENCIES -
COMMITMENTS AND CONTINGENCIES - Part 1 (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Operating Leased Assets [Line Items] | |||
Operating Leases, Rent Expense | $ 8.7 | $ 8.6 | $ 5 |
Operating Leases, Future Minimum Payments Due [Abstract] | |||
2,017 | 4.7 | ||
2,018 | 3.9 | ||
2,019 | 3.7 | ||
2,020 | 3.3 | ||
2,021 | 3.3 | ||
Thereafter | 3.2 | ||
Total | $ 22.1 |
COMMITMENTS AND CONTINGENCIES46
COMMITMENTS AND CONTINGENCIES - Part 2 (Details) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2016USD ($) | Dec. 31, 2017USD ($) | Jan. 01, 2017USD ($) | |
Commitments and Contingencies [Line Items] | |||
Number Of Former Manufactured Gas Sites Where We Own Or Retain Legal Responsibility For Environmental Conditions | 12 | ||
Number of MGP sites for which a remediation reserve was recorded | 1 | ||
Deferred MGP Costs, Maximum | $ 15,000 | ||
Regulatory assets | $ 440,522 | $ 405,189 | |
Number of sites with ongoing groundwater monitoring | 8 | ||
Number Of Sites Soil Remediation Is Completed Or Near Completion | 11 | ||
Number of sites where regulatory closure has been achieved | 3 | ||
Environmental Reserve Estimate Range, Low | 4 | ||
Environmental Reserve Estimate Range, High | 7 | ||
Environmental Reserve Estimate, Actual | 4 | ||
Percentage yield of high consequence pipeline areas | 30.00% | ||
MGP Costs [Member] | |||
Commitments and Contingencies [Line Items] | |||
Regulatory assets | $ 6,104 | $ 5,900 |
QUARTERLY FINANCIAL DATA (UNA47
QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ 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, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Schedule of Quarterly Financial Information [Line Items] | |||||||||||
Revenues | $ 462,394 | $ 247,142 | $ 279,689 | $ 550,408 | $ 440,754 | $ 232,191 | $ 245,923 | $ 508,364 | $ 1,539,633 | $ 1,427,232 | $ 1,547,692 |
Net margin | 925,132 | 885,435 | 841,733 | ||||||||
Operating income | 89,512 | 40,780 | 44,052 | 125,132 | 78,534 | 30,892 | 43,621 | 116,073 | 299,476 | 269,120 | 239,129 |
Net income | $ 47,119 | $ 18,797 | $ 20,623 | $ 76,456 | $ 42,315 | $ 12,737 | $ 20,300 | $ 64,743 | $ 162,995 | $ 140,095 | $ 119,030 |
Basic | $ 0.90 | $ 0.36 | $ 0.39 | $ 1.45 | $ 0.81 | $ 0.24 | $ 0.39 | $ 1.23 | $ 3.10 | $ 2.67 | $ 2.26 |
Diluted | $ 0.89 | $ 0.36 | $ 0.39 | $ 1.44 | $ 0.80 | $ 0.24 | $ 0.38 | $ 1.22 | $ 3.08 | $ 2.65 | $ 2.24 |