ONE Gas (OGS) 10-Q 1 Aug 23 2023 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2023	Jul. 24, 2023
Document Information [Line Items]
Document Type	10-Q
Document Period End Date	Jun. 30, 2023
Entity Registrant Name	ONE Gas, Inc.
Entity Central Index Key	0001587732
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Information [Line Items]
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-36108
Entity Incorporation, State or Country Code	OK
Entity Tax Identification Number	46-3561936
Entity Address, Address Line One	15 East Fifth Street
Entity Address, City or Town	Tulsa,
Entity Address, State or Province	OK
Entity Address, Postal Zip Code	74103
City Area Code	(918)
Local Phone Number	947-7000
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	OGS
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		55,449,300

STATEMENTS OF INCOME

STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Regulated Operating Revenue	$ 398,114	$ 428,975	$ 1,430,257	$ 1,400,434
Cost of natural gas	130,241	188,251	796,040	828,197
Operating expenses
Operations and maintenance	118,614	110,579	245,298	225,674
Depreciation and amortization	67,547	55,043	138,811	112,180
General taxes	17,690	16,533	36,856	35,057
Total operating expenses	203,851	182,155	420,965	372,911
Operating income	64,022	58,569	213,252	199,326
Other Nonoperating Income (Expense)	2,174	(3,983)	4,755	(8,128)
Interest expense, net	(27,485)	(16,320)	(57,600)	(31,915)
Income before income taxes	38,711	38,266	160,407	159,283
Income taxes	(6,022)	(6,191)	(25,097)	(28,274)
Net income	$ 32,689	$ 32,075	$ 135,310	$ 131,009
Earnings per share
Basic	$ 0.59	$ 0.59	$ 2.43	$ 2.42
Diluted	$ 0.58	$ 0.59	$ 2.42	$ 2.42
Weighted Average Number of Shares Outstanding, Basic [Abstract]
Basic	55,566	54,262	55,552	54,092
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Diluted	55,914	54,335	55,857	54,183
Common Stock, Dividends, Per Share, Declared	$ 0.65	$ 0.62	$ 1.30	$ 1.24

STATEMENTS OF COMPREHENSIVE INC

STATEMENTS OF COMPREHENSIVE INCOME STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Net income	$ 32,689	$ 32,075	$ 135,310	$ 131,009
Change in pension and other postemployment benefit plan liability, net of tax of $—, $(10), $— and $(29), respectively	0	30	0	99
Other comprehensive income, net of tax	0	30	0	99
Comprehensive income	32,689	32,105	135,310	131,108
Pension and other postemployment benefit plans, tax	$ 0	$ (10)	$ 0	$ (29)

STATEMENTS OF COMPREHENSIVE I_2

STATEMENTS OF COMPREHENSIVE INCOME STATEMENTS OF COMPREHENSIVE INCOME Parenthetical - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Pension and other postemployment benefit plans, tax	$ 0	$ (10)	$ 0	$ (29)

BALANCE SHEETS

BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Property, plant and equipment
Property, plant and equipment	$ 8,117,663	$ 7,834,557
Accumulated depreciation and amortization	2,261,035	2,205,717
Net property, plant and equipment	5,856,628	5,628,840
Cash and Cash Equivalents	7,332	9,681
Restricted Cash and Cash Equivalents	32,006	8,446
Cash, cash equivalents, restricted cash and restricted cash equivalents	39,338	18,127
Current assets
Accounts receivable, net	234,409	553,834
Materials and supplies	72,594	70,873
Natural Gas in Storage	144,742	269,205
Regulatory assets, Current	64,912	275,572
Other current assets	31,294	29,997
Total current assets	587,289	1,217,608
Goodwill and other assets
Regulatory assets, Noncurrent	304,614	330,831
Other Intangible Assets, Net	309,569	323,838
Goodwill	157,953	157,953
Other assets	119,069	117,326
Total goodwill and other assets	891,205	929,948
Total assets	7,335,122	7,776,396
Equity and long-term debt
Common stock, $0.01 par value: authorized 250,000,000 shares; issued and outstanding 55,446,841 shares at June 30, 2023; issued and outstanding 55,349,954 shares at December 31, 2022	554	553
Paid-in Capital	1,940,446	1,932,714
Retained earnings	714,530	651,863
Accumulated other comprehensive loss	(704)	(704)
Total equity	2,654,826	2,584,426
Other Long-Term Debt, Noncurrent	1,580,263	2,352,400
Securitized utility tariff bonds, excluding current maturities, net of issuance costs	295,949	309,343
Long-Term Debt, Excluding Current Maturities, Total	1,876,212	2,661,743
Total equity and long-term debt	4,531,038	5,246,169
Current liabilities
Long-term Debt, Current Maturities	772,838	12
Current maturities of securitized utility tariff bonds	34,201	20,716
Short-term debt	217,100	552,000
Accounts payable	154,121	360,493
Accrued taxes other than income	54,400	78,352
Regulatory Liability, Current	79,686	47,867
Customer deposits	54,635	57,854
Other current liabilities	87,110	72,125
Total current liabilities	1,454,091	1,189,419
Deferred credits and other liabilities
Deferred income taxes	727,184	698,456
Regulatory Liability, Noncurrent	512,633	529,441
Employee benefit obligations	19,620	19,587
Other deferred credits	90,556	93,324
Liabilities, Other than Long-term Debt, Noncurrent	1,349,993	1,340,808
Commitments and contingencies
Total liabilities and equity	$ 7,335,122	$ 7,776,396

BALANCE SHEETS BALANCE SHEETS P

BALANCE SHEETS BALANCE SHEETS Parenthetical - $ / shares	Jun. 30, 2023	Dec. 31, 2022
Common Stock, Par or Stated Value Per Share	$ 0.01
Common Stock, Shares Authorized	250,000,000
Common Stock, Shares, Issued	55,446,841	55,349,954
Common Stock, Shares, Outstanding	55,446,841	55,349,954

STATEMENTS OF CASH FLOWS

STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Operating activities
Net income	$ 135,310	$ 131,009
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	138,811	112,180
Deferred income taxes	11,912	(18,780)
Share-based compensation expense	6,305	5,699
Provision for doubtful accounts	4,880	2,511
Proceeds from Securitization Bonds, Operating Activities	197,366	0
Changes in assets and liabilities:
Accounts receivable	314,545	100,955
Materials and supplies	(1,721)	(7,927)
Natural gas in storage	124,463	(18,660)
Payments for Removal Costs	(32,551)	(20,919)
Accounts payable	(198,968)	(92,887)
Accrued taxes other than income	(23,952)	(8,852)
Customer deposits	(3,219)	(2,177)
Increase (Decrease) In Regulatory Assets And Liabilities Current, net	35,633	43,697
Increase (Decrease) In Regulatory Assets And Liabilities Noncurrent, net	26,217	56,135
Increase (Decrease) in Other Current Assets and Liabilities, Net	12,156	8,234
Increase (Decrease) in Other Noncurrent Assets and Liabilities, Net	1,555	(3,541)
Cash provided by operating activities	748,742	286,677
Investing activities
Capital expenditures	(322,231)	(251,060)
Payments for Other Investing Activities	(1,647)	(1,332)
Proceeds from Sale of Other Assets, Investing Activities	2,462	891
Cash used in investing activities	(321,416)	(251,501)
Financing activities
Borrowings (repayments) of short-term debt, net	(334,900)	(3,900)
Proceeds from Issuance of Common Stock	3,175	37,104
Dividends paid	(72,006)	(66,821)
Payment, Tax Withholding, Share-based Payment Arrangement	(2,384)	(3,026)
Cash used in financing activities	(406,115)	(36,643)
Change in cash and cash equivalents	21,211	(1,467)
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Beginning Balance	18,127	8,852
Cash, cash equivalents, restricted cash and restricted cash equivalents at end of period	39,338	7,385
Interest Paid, Excluding Capitalized Interest, Operating Activities	47,773	41,600
Income Taxes Paid, Net	$ 9,174	$ 16,200

STATEMENT OF CHANGES IN EQUITY

STATEMENT OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Shares issued, beginning balance at Dec. 31, 2021		53,633,210
Common stock issued, shares		456,607
Shares issued, ending balance at Mar. 31, 2022		54,089,817
Equity, beginning balance at Dec. 31, 2021	$ 2,349,532	$ 536	$ 1,790,362	$ 565,161	$ (6,527)
Net income	98,934	0	0	98,934	0
Other comprehensive income	69	0	0	0	69
Common stock issued, value	$ 34,140	5	34,135	0	0
Dividends paid per share of stock	$ 0.62
Dividends, Common Stock	$ (33,285)	0	274	(33,559)	0
Equity, ending balance at Mar. 31, 2022	2,449,390	$ 541	1,824,771	630,536	(6,458)
Shares issued, beginning balance at Dec. 31, 2021		53,633,210
Shares issued, ending balance at Jun. 30, 2022		54,137,217
Equity, beginning balance at Dec. 31, 2021	2,349,532	$ 536	1,790,362	565,161	(6,527)
Net income	131,009
Other comprehensive income	99
Equity, ending balance at Jun. 30, 2022	2,453,596	$ 541	1,830,678	628,805	(6,428)
Shares issued, beginning balance at Mar. 31, 2022		54,089,817
Common stock issued, shares		47,400
Shares issued, ending balance at Jun. 30, 2022		54,137,217
Equity, beginning balance at Mar. 31, 2022	2,449,390	$ 541	1,824,771	630,536	(6,458)
Net income	32,075	0	0	32,075	0
Other comprehensive income	30	0	0	0	30
Common stock issued, value	$ 5,636	0	5,636	0	0
Dividends paid per share of stock	$ 0.62
Dividends, Common Stock	$ (33,535)	0	271	(33,806)	0
Equity, ending balance at Jun. 30, 2022	$ 2,453,596	$ 541	1,830,678	628,805	(6,428)
Shares issued, beginning balance at Dec. 31, 2022	55,349,954	55,349,954
Common stock issued, shares		39,096
Shares issued, ending balance at Mar. 31, 2023		55,389,050
Equity, beginning balance at Dec. 31, 2022	$ 2,584,426	$ 553	1,932,714	651,863	(704)
Net income	102,621	0	0	102,621	0
Common stock issued, value	$ 435		435	0	0
Dividends paid per share of stock	$ 0.65
Dividends, Common Stock	$ (36,002)	0	319	(36,321)	0
Equity, ending balance at Mar. 31, 2023	$ 2,651,480	$ 553	1,933,468	718,163	(704)
Shares issued, beginning balance at Dec. 31, 2022	55,349,954	55,349,954
Shares issued, ending balance at Jun. 30, 2023	55,446,841	55,446,841
Equity, beginning balance at Dec. 31, 2022	$ 2,584,426	$ 553	1,932,714	651,863	(704)
Net income	135,310
Other comprehensive income	0
Equity, ending balance at Jun. 30, 2023	$ 2,654,826	$ 554	1,940,446	714,530	(704)
Shares issued, beginning balance at Mar. 31, 2023		55,389,050
Common stock issued, shares		57,791
Shares issued, ending balance at Jun. 30, 2023	55,446,841	55,446,841
Equity, beginning balance at Mar. 31, 2023	$ 2,651,480	$ 553	1,933,468	718,163	(704)
Net income	32,689	0	0		0
Other comprehensive income	0
Common stock issued, value	$ 6,661	1	6,660	0	0
Dividends paid per share of stock	$ 0.65
Dividends, Common Stock	$ (36,004)	0	318	(36,322)	0
Equity, ending balance at Jun. 30, 2023	$ 2,654,826	$ 554	$ 1,940,446	$ 714,530	$ (704)

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Notes)	6 Months Ended
	Jun. 30, 2023
Significant Accounting Policies [Line Items]
SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Our accompanying unaudited consolidated financial statements have been prepared pursuant to the rules and regulations of the SEC. These statements also have been prepared in accordance with GAAP and reflect all adjustments that, in our opinion, are necessary for a fair statement of the results for the interim periods presented. All such adjustments are of a normal recurring nature. The 2022 year-end consolidated balance sheet data was derived from audited consolidated financial statements but does not include all disclosures required by GAAP. These unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and footnotes in our Annual Report. Our significant accounting policies are described in Note 1 of our Notes to Consolidated Financial Statements in our Annual Report. The preparation of these financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts and disclosures in the financial statements. Although management believes these estimates are reasonable, actual results could differ materially from these estimates. Due to the seasonal nature of our business, the results of operations for the six months ended June 30, 2023, are not necessarily indicative of the results that may be expected for a 12-month period. We provide natural gas distribution services to approximately 2.3 million customers in Oklahoma, Kansas and Texas through our three divisions, Oklahoma Natural Gas, Kansas Gas Service and Texas Gas Service, respectively. We primarily serve residential, commercial and transportation customers in all three states. Segments - We operate in one reportable business segment: regulated public utilities that deliver natural gas primarily to residential, commercial and transportation customers. Our accounting policies are the same as those described in Note 1 of the Notes to Consolidated Financial Statements in our Annual Report. We evaluate our financial performance principally on net income. For the three and six months ended June 30, 2023 and 2022, we had no single external customer from which we received 10 percent or more of our gross revenues. Property, Plant and Equipment and Asset Removal Costs - Accounts payable for construction work in progress and asset removal costs decreased by approximately $7.9 million and $7.8 million for the six months ended June 30, 2023 and 2022, respectively. Such amounts are not included in capital expenditures or asset removal costs in our consolidated statements of cash flows. Accounts Receivable, net - Accounts receivable represent valid claims against nonaffiliated customers for natural gas sold or services rendered. We assess the creditworthiness of our customers. Those customers who do not meet minimum standards may be required to provide security, including deposits and other forms of collateral, when appropriate and allowed by our tariffs. With approximately 2.3 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 environment and other information. We recover natural gas costs related to accounts written off when they are deemed uncollectible through the purchased-gas cost adjustment mechanisms in each of our jurisdictions. At June 30, 2023 and December 31, 2022, our allowance for doubtful accounts was $17.0 million and $16.7 million, respectively. Reclassifications -A reclassification has been made in the prior-year financial statements to conform to the current-year presentation. We have updated our consolidated balance sheet at December 31, 2022, to disaggregate “current maturities of other long-term debt,” which had previously been included in “other current liabilities,” to conform to our current-year presentation.

REVENUE (Notes)

REVENUE (Notes)	6 Months Ended
	Jun. 30, 2023
Revenue from Contract with Customer	REVENUE The following table sets forth our revenues disaggregated by source for the periods indicated: Three Months Ended Six Months Ended June 30, June 30, 2023 2022 2023 2022 (Thousands of dollars) Natural gas sales to customers $ 346,734 $ 393,292 $ 1,313,093 $ 1,318,449 Transportation revenues 29,022 28,000 67,549 64,316 Securitization customer charges (Note 14) 11,807 — 23,740 — Miscellaneous revenues 6,313 5,128 12,211 9,624 Total revenues from contracts with customers 393,876 426,420 1,416,593 1,392,389 Other revenues - natural gas sales related 1,614 (115) 7,404 2,231 Other revenues 2,624 2,670 6,260 5,814 Total other revenues 4,238 2,555 13,664 8,045 Total revenues $ 398,114 $ 428,975 $ 1,430,257 $ 1,400,434

REGULATORY ASSETS AND LIABILITI

REGULATORY ASSETS AND LIABILITIES (Notes)	6 Months Ended
	Jun. 30, 2023
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Schedule of Regulatory Assets and Liabilities	REGULATORY ASSETS AND LIABILITIES The tables below present a summary of regulatory assets and liabilities, net of amortization, for the periods indicated: June 30, 2023 Current Noncurrent Total ( Thousands of dollars ) Winter weather event costs $ 22,633 $ 26,117 $ 48,750 Pension and postemployment benefit costs 4,603 239,975 244,578 Reacquired debt costs 812 2,985 3,797 MGP remediation costs 98 31,891 31,989 Ad-valorem tax 12,125 — 12,125 WNA 7,809 — 7,809 Customer credit deferrals 13,820 — 13,820 Other 3,012 3,646 6,658 Total regulatory assets, net of amortization 64,912 304,614 369,526 Income tax rate changes — (512,633) (512,633) Over-recovered purchased-gas costs (79,686) — (79,686) Total regulatory liabilities (79,686) (512,633) (592,319) Net regulatory assets and liabilities $ (14,774) $ (208,019) $ (222,793) December 31, 2022 Current Noncurrent Total ( Thousands of dollars ) Winter weather event costs $ 221,926 $ 36,291 $ 258,217 Under-recovered purchased-gas costs 19,755 — 19,755 Pension and postemployment benefit costs — 258,257 258,257 Reacquired debt costs 812 3,347 4,159 MGP remediation costs 98 29,743 29,841 Ad-valorem tax 13,359 — 13,359 WNA 8,474 — 8,474 Customer credit deferrals 9,504 — 9,504 Other 1,644 3,193 4,837 Total regulatory assets, net of amortization 275,572 330,831 606,403 Pension and other postemployment benefit costs (8,228) — (8,228) Income tax rate changes — (529,441) (529,441) Over-recovered purchased-gas costs (39,639) — (39,639) Total regulatory liabilities (47,867) (529,441) (577,308) Net regulatory assets and liabilities $ 227,705 $ (198,610) $ 29,095 Regulatory assets in our consolidated balance sheets, as authorized by various regulatory authorities, are probable of recovery. Base rates and certain riders are designed to provide a recovery of costs during the period such 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 are subject to review by the respective regulatory authorities during future regulatory proceedings. We are not aware of any evidence that these costs will not be recoverable through either riders, base rates, or securitization. Winter weather event costs - In February 2021, the U.S. experienced Winter Storm Uri, a historic winter weather event impacting supply, market pricing and demand for natural gas in a number of states, including our service territories of Oklahoma, Kansas, and Texas. During this time, the governors of Oklahoma, Kansas, and Texas each declared a state of emergency, and certain regulatory agencies issued emergency orders that impacted the utility and natural gas industries, including statewide utility curtailment programs and orders requiring jurisdictional natural gas and electric utilities to do all things possible and necessary to ensure that natural gas and electricity utility services continued to be provided to their customers. Due to the historic nature of this winter weather event, we experienced unforeseeable and unprecedented market pricing for natural gas in our Oklahoma, Kansas, and Texas jurisdictions, which resulted in aggregated natural gas purchases for the month of February 2021 of approximately $2.1 billion. Each state enacted securitization legislation to allow for recovery of the extraordinary gas costs, as well as other authorized expenses related to Winter Storm Uri. Securitization proceeds were received for Oklahoma and Kansas in 2022, and for Texas in 2023. See our Annual Report for more discussion of events surrounding Winter Storm Uri and the securitization of the related regulatory assets. Texas - Pursuant to securitization legislation enacted in Texas as a result of Winter Storm Uri and a June 2021 RRC Notice to Gas Utilities, Texas Gas Service submitted an application to the RRC in July 2021, for an order authorizing the amount of extraordinary costs for recovery and other such specifications necessary for the issuance of securitized bonds. In February 2022, the RRC issued a single financing order for Texas Gas Service and other natural gas utilities in Texas participating in the securitization process, which included a determination that the approved costs will be collected from customers over a period of not more than 30 years. The TPFA formed the TNG Corporation, a new independent public authority, to issue the securitized bonds. In March 2023, the TNG Corporation completed the issuance of the Customer Rate Relief (Winter Storm Uri), Taxable Series 2023 Bonds and we received our portion of the net proceeds, which was approximately $197 million. The proceeds were used to repay certain indebtedness and for general corporate purposes. Interest costs that exceeded the amount securitized have been deferred and will be addressed in the next general rate proceeding in each jurisdiction in Texas. At June 30, 2023, Texas Gas Service had deferred approximately $31.2 million in extraordinary costs associated with Winter Storm Uri attributable to its former West Texas service area. Pursuant to the approved settlement order, Texas Gas Service began collecting the extraordinary costs, including carrying costs, from those customers in January 2022. The deferred winter weather event costs also include invoiced costs for natural gas purchases during Winter Storm Uri that have not been paid as we work with our suppliers for Kansas and Texas to resolve discrepancies in invoiced amounts. These amounts may be adjusted as the differences with suppliers are resolved. Settlements of these amounts are recoverable through the purchased gas cost mechanisms in the respective state. Future adjustments to the amounts are not expected to have a material impact on earnings. Other regulatory assets and liabilities - 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. 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 the net periodic benefit cost for defined benefit pension and other postemployment costs. Differences, if any, between the net periodic benefit cost, net of deferrals, and the amount recovered through rates are reflected in earnings. 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. We amortize reacquired debt costs in accordance with the accounting guidelines prescribed by the OCC and the KCC. See Note 12 for additional information regarding our regulatory assets for MGP remediation costs. Ad-valorem tax represents the difference in Kansas Gas Service’s taxes incurred each year above or below the amount approved in base rates. This difference is deferred as a regulatory asset or liability for a 12-month period. Kansas Gas Service then applies an adjustment to customers’ bills to refund the over-collected revenue or bill the under-collected revenue over the subsequent 12 months. 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. The customer credit deferrals and the noncurrent regulatory liability for income tax rate changes represents deferral of the effects of enacted federal and state income tax rate changes on our ADIT and the effects of these changes on our rates. See Note 10 for additional information regarding the impact of income tax rate changes. Recovery through rates resulted in amortization of regulatory assets of approximately $2.5 million and $1.6 million for the three months ended June 30, 2023 and 2022, respectively, and approximately $9.5 million and $6.0 million for the six months ended June 30, 2023 and 2022, respectively.

CREDIT FACILITIES (Notes)

CREDIT FACILITIES (Notes)	6 Months Ended
	Jun. 30, 2023
Short-term Debt [Line Items]
Short-term Debt [Text Block]	CREDIT FACILITY AND SHORT-TERM DEBT In March 2023, we entered into an extension agreement related to the ONE Gas Credit Agreement that extended the maturity date to March 16, 2028, from March 16, 2027. All other terms and conditions of the ONE Gas Credit Agreement remain in full force and effect. The ONE Gas Credit Agreement provides for a $1.0 billion revolving unsecured credit facility and includes a $20 million letter of credit subfacility. We can 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 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. At June 30, 2023, our total debt-to-capital ratio was 52 percent and we were in compliance with all covenants under the ONE Gas Credit Agreement. We may reduce the unutilized portion of the ONE Gas Credit Agreement in whole or in part without premium or penalty. The ONE Gas Credit Agreement contains customary events of default. Upon the occurrence of certain events of default, the obligations under the ONE Gas Credit Agreement may be accelerated and the commitments may be terminated. At June 30, 2023, we had $1.2 million in letters of credit issued and no borrowings under the ONE Gas Credit Agreement, with $998.8 million of remaining credit, which is available to repay our commercial paper borrowings. We have a commercial paper program under which we may issue unsecured commercial paper up to a maximum amount of $1.0 billion to fund short-term borrowing needs. The maturities of the commercial paper vary but may not exceed 270 days from the date of issue. Commercial paper is generally sold at par less a discount representing an interest factor. At June 30, 2023 and December 31, 2022, we had $217.1 million and $552.0 million of commercial paper outstanding with a weighted-average interest rate of 5.43 percent and 4.75 percent, respectively.

LONG-TERM DEBT (Notes)

LONG-TERM DEBT (Notes)	6 Months Ended
	Jun. 30, 2023
Long-Term Debt, Unclassified [Abstract]
Long-term Debt [Text Block]	LONG-TERM DEBT The table below presents a summary of our long-term debt outstanding for the periods indicated: Interest rate at June 30, 2023 June 30, 2023 December 31, 2022 ( Thousands of dollars ) Senior Notes due: February 2024 3.610% $ 300,000 $ 300,000 March 2024 1.100% 473,000 473,000 May 2030 2.000% 300,000 300,000 September 2032 4.250% 300,000 300,000 February 2044 4.658% 600,000 600,000 November 2048 4.500% 400,000 400,000 Total Senior Notes 2,373,000 2,373,000 KGSS-I Securitized Utility Tariff Bonds 5.486% 336,000 336,000 Other 8.000% 1,244 1,250 Unamortized discounts on long-term debt (7,422) (7,636) Debt issuance costs (a) (19,571) (20,143) Total long-term debt, net 2,683,251 2,682,471 Less: current maturities of securitized utility tariff bonds 34,201 20,716 Less: current maturities of other long-term debt, net 772,838 12 Noncurrent portion of long-term debt, net $ 1,876,212 $ 2,661,743 (a) Includes $5.8 million of issuance costs for the KGSS-I Securitized Utility Tariff Bonds. Senior Notes - 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 aggregate principal amount of the outstanding Senior Notes to declare those Senior Notes immediately due and payable in full. Depending on the series, we may redeem our Senior Notes at par, plus accrued and unpaid interest to the redemption date, starting three months or six months 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 Senior Note plus accrued and unpaid interest to the redemption date. Our $473 million of 1.10 percent senior notes due March 2024 can be called at par with a 30-day notice. Our Senior Notes are senior unsecured obligations, ranking equally in right of payment with all of our existing and future unsecured senior indebtedness. Securitized Utility Tariff Bonds - The KGSS-I Securitized Utility Tariff Bonds are governed by an indenture between KGSS-I and the indenture trustee. The indenture contains certain covenants that restrict KGSS-I’s ability to sell, transfer, convey, exchange, or otherwise dispose of its assets. See Note 14 for additional discussion of the Kansas securitization transaction.

EQUITY (Notes)

EQUITY (Notes)	6 Months Ended
	Jun. 30, 2023
Class of Stock [Line Items]
Stockholders' Equity Note Disclosure [Text Block]	EQUITY Equity Forward Agreement - In March 2023, we entered into an underwriting agreement and a forward sale agreement for 2.0 million shares of our common stock. The forward sale agreement provides for settlement on a date, or dates, to be specified at our discretion, but which will occur no later than December 29, 2023, for 1.4 million shares of common stock and by December 31, 2024, for the remaining balance. At-the-Market Equity Program - In February 2023, we entered into an at-the-market equity distribution agreement under which we may issue and sell shares of our common stock with an aggregate offering price up to $300 million (including any shares of common stock that may be sold pursuant to the master forward sale confirmation entered into in connection with the equity distribution agreement and the related supplemental confirmations). This at-the-market equity program replaced our previous at-the-market equity program, which began in February 2020, and expired in February 2023. The program allows us to offer and sell our common stock at prices we deem appropriate. Sales of common stock are made by means of ordinary brokers’ transactions on the NYSE, in block transactions or as otherwise agreed to between us and the sales agent. We are under no obligation to offer and sell common stock under the program. At June 30, 2023, we had $226.1 million of equity available for issuance under the program. For the six months ended June 30, 2023, we executed forward sale agreements under our current at-the-market equity program for 926,465 shares of our common stock. The following table summarizes all of our outstanding forward sale agreements at June 30, 2023: Maturity Shares Sold Net Proceeds Available Forward Price At-the-Market Equity Program December 29, 2023 289,403 $ 21,780 $ 75.26 December 31, 2024 926,465 73,906 $ 79.77 Total At-the-Market Equity Program 1,215,868 95,686 $ 78.70 Equity Forward Agreement December 29, 2023 1,400,000 107,095 $ 76.50 December 31, 2024 600,000 45,898 $ 76.50 Total Equity Forward Agreement 2,000,000 152,993 $ 76.50 Total forward sale agreements 3,215,868 $ 248,679 $ 77.33 For the six months ended June 30, 2022, we executed forward sale agreements for 591,736 shares of our common stock. On December 30, 2022, we settled these forward sale agreements for net proceeds of $48.0 million. For the six months ended June 30, 2022, we issued and sold 403,792 shares of our common stock for $35.0 million, generating net proceeds of $34.7 million. Dividends Declared - In July 2023, we declared a dividend of $0.65 per share ($2.60 per share on an annualized basis) for shareholders of record as of August 16, 2023, payable on September 1, 2023.

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Notes)	6 Months Ended
	Jun. 30, 2023
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Comprehensive Income (Loss) Note	ACCUMULATED OTHER COMPREHENSIVE LOSS The following table sets forth the effect of reclassifications from accumulated other comprehensive loss in our consolidated statements of income for the periods indicated: Three Months Ended Six Months Ended Affected Line Item in the Details About Accumulated Other June 30, June 30, Consolidated Statements Comprehensive Loss Components 2023 2022 2023 2022 of Income ( Thousands of dollars ) Pension and other postemployment benefit plan obligations (a) Amortization of net loss $ 490 $ 4,252 $ 980 $ 12,453 Amortization of unrecognized prior service cost (credit) 131 72 262 82 621 4,324 1,242 12,535 Regulatory adjustments (b) (621) (4,265) (1,242) (12,388) — 59 — 147 Income before income taxes — (15) — (34) Income tax expense Total reclassifications for the period $ — $ 44 $ — $ 113 Net income (a) These components of accumulated other comprehensive loss are included in the computation of net periodic benefit cost. See Note 9 for additional detail of 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 3 for additional disclosures of regulatory assets and liabilities.

EARNINGS PER SHARE (Notes)

EARNINGS PER SHARE (Notes)	6 Months Ended
	Jun. 30, 2023
EARNINGS PER SHARE [Line Items]
Earnings Per Share [Text Block]	EARNINGS PER SHARE Basic EPS is calculated by dividing net income by the daily weighted-average number of common shares outstanding during the periods presented, which includes fully vested stock awards that have not yet been issued as common stock. Diluted EPS is based on shares outstanding for the calculation of basic EPS, plus unvested stock awards granted under our compensation plans and equity forward sale agreements, but only to the extent these instruments dilute earnings per share. The following tables set forth the computation of basic and diluted EPS from continuing operations for the periods indicated: Three Months Ended June 30, 2023 Income Shares Per Share ( Thousands, except per share amounts ) Basic EPS Calculation Net income available for common stock $ 32,689 55,566 $ 0.59 Diluted EPS Calculation Effect of dilutive securities — 348 Net income available for common stock and common stock equivalents $ 32,689 55,914 $ 0.58 Three Months Ended June 30, 2022 Income Shares Per Share ( Thousands, except per share amounts ) Basic EPS Calculation Net income available for common stock $ 32,075 54,262 $ 0.59 Diluted EPS Calculation Effect of dilutive securities — 73 Net income available for common stock and common stock equivalents $ 32,075 54,335 $ 0.59 Six Months Ended June 30, 2023 Income Shares Per Share ( Thousands, except per share amounts ) Basic EPS Calculation Net income available for common stock $ 135,310 55,552 $ 2.43 Diluted EPS Calculation Effect of dilutive securities — 305 Net income available for common stock and common stock equivalents $ 135,310 55,857 $ 2.42 Six Months Ended June 30, 2022 Income Shares Per Share ( Thousands, except per share amounts ) Basic EPS Calculation Net income available for common stock $ 131,009 54,092 $ 2.42 Diluted EPS Calculation Effect of dilutive securities — 91 Net income available for common stock and common stock equivalents $ 131,009 54,183 $ 2.42

EMPLOYEE BENEFIT PLANS (Notes)

EMPLOYEE BENEFIT PLANS (Notes)	6 Months Ended
	Jun. 30, 2023
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Employee Benefit Plans (Notes)	EMPLOYEE BENEFIT PLANS The following tables set forth the components of net periodic benefit cost for our pension and other postemployment benefit plans for the periods indicated: Pension Benefits Three Months Ended Six Months Ended June 30, June 30, 2023 2022 2023 2022 (Thousands of dollars) Components of net periodic benefit cost (credit) Service cost $ 1,811 $ 2,592 $ 3,622 $ 5,686 Interest cost 10,607 9,037 21,214 16,841 Expected return on assets (14,879) (14,632) (29,758) (29,245) Amortization of unrecognized prior service cost 93 62 186 62 Amortization of net loss 502 4,198 1,004 12,345 Net periodic benefit cost (credit) $ (1,866) $ 1,257 $ (3,732) $ 5,689 Other Postemployment Benefits Three Months Ended Six Months Ended June 30, June 30, 2023 2022 2023 2022 ( Thousands of dollars ) Components of net periodic benefit cost (credit) Service cost $ 183 $ 318 $ 366 $ 636 Interest cost 2,288 1,612 4,576 3,224 Expected return on assets (2,432) (3,295) (4,864) (6,590) Amortization of unrecognized prior service cost 38 10 76 20 Amortization of net (gain) loss (12) 54 (24) 108 Net periodic benefit cost (credit) $ 65 $ (1,301) $ 130 $ (2,602) We recover qualified pension benefit plan and other postemployment benefit plan costs through rates charged to our customers. Certain regulatory authorities require that the recovery of these costs be based on specific guidelines. The difference between these regulatory-based amounts and the periodic benefit cost calculated pursuant to GAAP is deferred as a regulatory asset or liability and amortized to expense over periods in which this difference will be recovered in rates, as authorized by the applicable regulatory authorities. For the six months ended June 30, 2023 and 2022, regulatory deferrals related to net periodic benefit cost were not material. We capitalize all eligible service cost and non-service cost components under the accounting requirements of ASC Topic 980 (Regulated Operations) for rate-regulated entities. Capitalized non-service costs reflected as a regulatory asset in our consolidated balance sheets were not material at June 30, 2023, and were $2.8 million at December 31, 2022. See Note 3 of the Notes to Consolidated Financial Statements in this Quarterly Report for additional information.

INCOME TAXES (Notes)

INCOME TAXES (Notes)	6 Months Ended
	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Income Tax Disclosure	INCOME TAXES We use an estimated annual effective tax rate for purposes of determining the income tax provision during interim reporting periods. In calculating our estimated annual effective tax rate, we consider forecasted annual pre-tax income and estimated permanent book versus tax differences, as well as tax credits. Adjustments to the effective tax rate and estimates will occur as information and assumptions change. At June 30, 2023, we have no uncertain tax positions. Changes in tax laws or tax rates are recognized in the financial reporting period that includes the enactment date. We are no longer subject to income tax examination for years prior to 2018. Income tax expense reflects credits for the amortization of the regulatory liability associated with EDIT that was returned to customers of $3.1 million and $3.0 million for the three months ended June 30, 2023 and 2022, respectively, and credits of $13.0 million and $10.9 million for the six months ended June 30, 2023 and 2022, respectively.

OTHER INCOME AND OTHER EXPENSE

OTHER INCOME AND OTHER EXPENSE (Notes)	6 Months Ended
	Jun. 30, 2023
Other Income and Other Expense Disclosure [Text Block]	OTHER INCOME AND OTHER EXPENSE The following table sets forth the components of other income and other expense for the periods indicated: Three Months Ended Six Months Ended June 30, June 30, 2023 2022 2023 2022 ( Thousands of dollars ) Net periodic benefit credit other than service cost $ 963 $ 1,366 $ 1,871 $ 778 Earnings (losses) on investments associated with nonqualified employee benefit plans 1,274 (4,619) 2,887 (7,452) Other, net (63) (730) (3) (1,454) Total other income (expense), net $ 2,174 $ (3,983) $ 4,755 $ (8,128)

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Notes)	6 Months Ended
	Jun. 30, 2023
Commitments and Contingencies [Line Items]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Environmental Matters - We are subject to multiple laws and regulations regarding protection of the environment and natural and cultural resources, 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, plant and wildlife protection, hazardous materials use, storage and 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 or the discovery of presently unknown environmental conditions 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 CAA 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 the three and six months ended June 30, 2023 and 2022. 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. Regulatory closure has been achieved at five of the 12 sites, but these sites remain subject to potential future requirements that may result in additional costs. We have an AAO that allows Kansas Gas Service to defer and seek recovery of costs necessary for investigation and remediation at, and nearby, these 12 former MGP sites that are incurred after January 1, 2017, up to a cap of $15.0 million, net of any related insurance recoveries. Costs approved for recovery 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. Following a determination that future investigation and remediation work approved by the KDHE is expected to exceed $15.0 million, net of any related insurance recoveries, Kansas Gas Service will be required to file an application with the KCC for approval to increase the $15.0 million cap. At June 30, 2023 and December 31, 2022, we have deferred $32.0 million for accrued investigation and remediation costs pursuant to our AAO. Kansas Gas Service expects to file an application as soon as practicable after the KDHE approves the plans we have submitted. We have completed or are addressing removal of the source of soil contamination at all 12 sites and continue to monitor groundwater at seven of the 12 sites according to plans approved by the KDHE. In 2019, we completed a project to remove a source of contamination and associated contaminated materials at the twelfth site where no active soil remediation had previously occurred. In 2022, we completed a remediation project to remove a source of contamination and contaminated materials at one of the MGP sites. In June 2023, we submitted a revised draft remediation plan to the KDHE for review following receipt of agency comments and public feedback. We also own or retain legal responsibility for certain environmental conditions at a former MGP site in Texas. At the request of the TCEQ, we began investigating the level and extent of contamination associated with the site under their Texas Risk Reduction Program. A preliminary site investigation revealed that this site contains contaminants generally associated with MGP sites and is subject to control or remediation under various environmental laws and regulations. Impacts have been identified in the soil and groundwater at the site with limited impacts observed in surrounding areas. In April 2022, we submitted a remediation work plan to address the areas impacted to the TCEQ. At June 30, 2023, estimated costs associated with expected remediation activities for this site are not material. 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 the three and six months ended June 30, 2023 and 2022. The reserve for remediation of our MGP sites was $14.8 million and $12.7 million at June 30, 2023 and December 31, 2022, respectively. Pipeline Safety - We are subject to regulation under federal pipeline safety statutes and any analogous state regulations. These include safety requirements for the design, construction, operation, and maintenance of pipelines, including transmission and distribution pipelines. At the federal level, we are regulated by PHMSA. PHMSA regulations require the following for certain pipelines: inspection and maintenance plans; integrity management programs, including the determination of pipeline integrity risks and periodic assessments on certain pipeline segments; an operator qualification program, which includes certain trainings; a public awareness program that provides certain information; and a control room management plan. As part of the Consolidated Appropriations Act, 2021, the PIPES Act reauthorized PHMSA through 2023 and directed the agency to move forward with several regulatory actions, including the “Pipeline Safety: Class Location Change Requirements” and the “Pipeline Safety: Safety of Gas Transmission and Gathering Pipelines” proposed rulemakings. Congress has also instructed PHMSA to issue final regulations that will require operators of new and existing transmission and distribution pipeline facilities to conduct certain leak detection and repair programs and to require facility inspection and maintenance plans to align with those regulations. To the extent such rulemakings impose more stringent requirements on our facilities, we may be required to incur expenditures that may be material. 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 outcome of such matters will not have a material adverse effect on our results of operations, financial position or cash flows.

DERIVATIVE FINANCIAL INSTRUMENT

DERIVATIVE FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS (Notes)	6 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Disclosures	DERIVATIVE FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS Accounting Treatment - 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 requirements impose 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. We have not elected to designate any of our derivative instruments as hedges. 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 - 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 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. Derivative Instruments - Our derivatives are comprised of over-the-counter natural gas fixed price swaps and call options. Swaps - At June 30, 2023, we held over-the-counter natural gas fixed-price swaps for the heating season ending March 2024, with a total notional amount of 7.7 Bcf. We did not hold any swaps at December 31, 2022. Options - At June 30, 2023, we held natural gas call options for the heating season ending March 2024, with total notional amounts of 0.7 Bcf, for which we paid premiums of $0.8 million. At December 31, 2022, we held purchased natural gas call options for the heating season ended March 2023, with total notional amounts of 19.4 Bcf, for which we paid premiums of $14.1 million. We have not designated any of our derivative instruments as accounting hedges. These contracts are included in, and recoverable through, our purchased-gas cost adjustment mechanisms. Additionally, premiums paid, changes in fair value and any settlements received associated with these contracts are deferred as part of our unrecovered purchased-gas costs in our consolidated balance sheets. There were no transfers between levels for the periods presented. Other Financial Instruments - The approximate fair value of cash and cash equivalents, restricted cash and cash equivalents, accounts receivable and accounts payable is equal to book value, due to the short-term nature of these items. Commercial paper is due upon demand and, therefore, the carrying amounts approximate fair value. The following tables summarize, by level within the fair value hierarchy, our derivative and other assets and liabilities that were accounted for at fair value on a recurring basis at June 30, 2023 and December 31, 2022: June 30, 2023 Level 1 Level 2 Netting (c) Total (Thousands of dollars) Assets: Derivative instruments - swaps (a) $ — $ 616 $ (616) $ — Derivative instruments - options (a) — 452 — 452 United States treasury notes (b) 4,020 — — 4,020 Corporate bonds (b) — 9,544 — 9,544 Total assets $ 4,020 $ 10,612 $ (616) $ 14,016 Liabilities: Derivative instruments - swaps (a) $ — $ 3,747 $ (616) $ 3,131 December 31, 2022 Level 1 Level 2 Total (Thousands of dollars) Assets: United States treasury notes (b) $ 4,695 $ — $ 4,695 Corporate bonds (b) — 9,710 9,710 Total assets $ 4,695 $ 9,710 $ 14,405 (a) The fair value is included in other current assets and other current liabilities in our consolidated balance sheets. (b) The fair value is included in other current and noncurrent assets and other current and noncurrent liabilities in our consolidated balance sheets. (c) Our over-the-counter natural gas fixed-price swaps are subject to netting arrangements.

VARIABLE INTEREST ENTITES (Note

VARIABLE INTEREST ENTITES (Notes)	6 Months Ended
	Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entity Disclosure	VARIABLE INTEREST ENTITY KGSS-I is a special-purpose, wholly owned subsidiary of ONE Gas that was formed for the purpose of issuing securitized bonds to recover extraordinary costs incurred by Kansas Gas Service resulting from Winter Storm Uri. On November 18, 2022, the securitized financing was complete. KGSS-I’s assets cannot be used to settle ONE Gas’ obligations and the holders of the Securitized Utility Tariff Bonds have no recourse against ONE Gas. See Note 5 for additional information about the securitization financing. KGSS-I is considered to be a variable interest entity. As a result, KGSS-I is included in the consolidated financial statements of ONE Gas. No gain or loss was recognized upon initial consolidation. The following table summarizes the impact of KGSS-I on our consolidated balance sheets, for the periods indicated: June 30, December 31, 2023 2022 (Thousands of dollars) Restricted cash and cash equivalents $ 32,006 $ 8,446 Accounts receivable 3,157 4,862 Securitized intangible asset, net 309,569 323,838 Current maturities of securitized utility tariff bonds 34,201 20,716 Accounts payable 1,483 3,204 Accrued interest 11,418 2,202 Securitized utility tariff bonds, excluding current maturities, net of $5.9 million of discounts and issuance costs 295,949 309,343 Equity 1,681 1,681 The following table summarizes the impact of KGSS-I on our consolidated statements of income, for the period indicated: Three Months Ended Six Months Ended June 30, 2023 June 30, 2023 (Thousands of dollars) Operating revenues $ 11,807 $ 23,740 Operating expense (109) (219) Amortization expense (7,180) (14,269) Interest income 226 301 Interest expense (4,744) (9,553) Income before income taxes $ — $ —

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
	Jun. 30, 2023
Significant Accounting Policies [Line Items]
Segments	Segments - We operate in one reportable business segment: regulated public utilities that deliver natural gas primarily to residential, commercial and transportation customers. Our accounting policies are the same as those described in Note 1 of the Notes to Consolidated Financial Statements in our Annual Report. We evaluate our financial performance principally on net income. For the three and six months ended June 30, 2023 and 2022, we had no single external customer from which we received 10 percent or more of our gross revenues.
Receivables, Trade and Other Accounts Receivable, Allowance for Doubtful Accounts, Policy [Policy Text Block]	Accounts Receivable, net - Accounts receivable represent valid claims against nonaffiliated customers for natural gas sold or services rendered. We assess the creditworthiness of our customers. Those customers who do not meet minimum standards may be required to provide security, including deposits and other forms of collateral, when appropriate and allowed by our tariffs. With approximately 2.3 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 environment and other information. We recover natural gas costs related to accounts written off when they are deemed uncollectible through the purchased-gas cost adjustment mechanisms in each of our jurisdictions. At June 30, 2023 and December 31, 2022, our allowance for doubtful accounts was $17.0 million and $16.7 million, respectively.
Reclassification, Comparability Adjustment	Reclassifications -A reclassification has been made in the prior-year financial statements to conform to the current-year presentation. We have updated our consolidated balance sheet at December 31, 2022, to disaggregate “current maturities of other long-term debt,” which had previously been included in “other current liabilities,” to conform to our current-year presentation.

DERIVATIVE FINANCIAL INSTRUME_2

DERIVATIVE FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS (Policies)	6 Months Ended
	Jun. 30, 2023
Accounting Policies [Abstract]
Derivatives	Accounting Treatment - 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 requirements impose 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. We have not elected to designate any of our derivative instruments as hedges. 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 - 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
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.

REVENUE (Tables)

REVENUE (Tables)	6 Months Ended
	Jun. 30, 2023
Revenues Disaggregated by Source [Table]	The following table sets forth our revenues disaggregated by source for the periods indicated: Three Months Ended Six Months Ended June 30, June 30, 2023 2022 2023 2022 (Thousands of dollars) Natural gas sales to customers $ 346,734 $ 393,292 $ 1,313,093 $ 1,318,449 Transportation revenues 29,022 28,000 67,549 64,316 Securitization customer charges (Note 14) 11,807 — 23,740 — Miscellaneous revenues 6,313 5,128 12,211 9,624 Total revenues from contracts with customers 393,876 426,420 1,416,593 1,392,389 Other revenues - natural gas sales related 1,614 (115) 7,404 2,231 Other revenues 2,624 2,670 6,260 5,814 Total other revenues 4,238 2,555 13,664 8,045 Total revenues $ 398,114 $ 428,975 $ 1,430,257 $ 1,400,434

REGULATORY ASSETS AND LIABILI_2

REGULATORY ASSETS AND LIABILITIES (Tables)	6 Months Ended
	Jun. 30, 2023
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES	The tables below present a summary of regulatory assets and liabilities, net of amortization, for the periods indicated: June 30, 2023 Current Noncurrent Total ( Thousands of dollars ) Winter weather event costs $ 22,633 $ 26,117 $ 48,750 Pension and postemployment benefit costs 4,603 239,975 244,578 Reacquired debt costs 812 2,985 3,797 MGP remediation costs 98 31,891 31,989 Ad-valorem tax 12,125 — 12,125 WNA 7,809 — 7,809 Customer credit deferrals 13,820 — 13,820 Other 3,012 3,646 6,658 Total regulatory assets, net of amortization 64,912 304,614 369,526 Income tax rate changes — (512,633) (512,633) Over-recovered purchased-gas costs (79,686) — (79,686) Total regulatory liabilities (79,686) (512,633) (592,319) Net regulatory assets and liabilities $ (14,774) $ (208,019) $ (222,793) December 31, 2022 Current Noncurrent Total ( Thousands of dollars ) Winter weather event costs $ 221,926 $ 36,291 $ 258,217 Under-recovered purchased-gas costs 19,755 — 19,755 Pension and postemployment benefit costs — 258,257 258,257 Reacquired debt costs 812 3,347 4,159 MGP remediation costs 98 29,743 29,841 Ad-valorem tax 13,359 — 13,359 WNA 8,474 — 8,474 Customer credit deferrals 9,504 — 9,504 Other 1,644 3,193 4,837 Total regulatory assets, net of amortization 275,572 330,831 606,403 Pension and other postemployment benefit costs (8,228) — (8,228) Income tax rate changes — (529,441) (529,441) Over-recovered purchased-gas costs (39,639) — (39,639) Total regulatory liabilities (47,867) (529,441) (577,308) Net regulatory assets and liabilities $ 227,705 $ (198,610) $ 29,095

LONG-TERM DEBT (Tables)

LONG-TERM DEBT (Tables)	6 Months Ended
	Jun. 30, 2023
Long-Term Debt, Unclassified [Abstract]
Schedule of Long-Term Debt Instruments	The table below presents a summary of our long-term debt outstanding for the periods indicated: Interest rate at June 30, 2023 June 30, 2023 December 31, 2022 ( Thousands of dollars ) Senior Notes due: February 2024 3.610% $ 300,000 $ 300,000 March 2024 1.100% 473,000 473,000 May 2030 2.000% 300,000 300,000 September 2032 4.250% 300,000 300,000 February 2044 4.658% 600,000 600,000 November 2048 4.500% 400,000 400,000 Total Senior Notes 2,373,000 2,373,000 KGSS-I Securitized Utility Tariff Bonds 5.486% 336,000 336,000 Other 8.000% 1,244 1,250 Unamortized discounts on long-term debt (7,422) (7,636) Debt issuance costs (a) (19,571) (20,143) Total long-term debt, net 2,683,251 2,682,471 Less: current maturities of securitized utility tariff bonds 34,201 20,716 Less: current maturities of other long-term debt, net 772,838 12 Noncurrent portion of long-term debt, net $ 1,876,212 $ 2,661,743

Equity (Tables)

Equity (Tables)	6 Months Ended
	Jun. 30, 2023
Equity [Abstract]
Schedule of Forward Contracts Indexed to Issuer's Equity	The following table summarizes all of our outstanding forward sale agreements at June 30, 2023: Maturity Shares Sold Net Proceeds Available Forward Price At-the-Market Equity Program December 29, 2023 289,403 $ 21,780 $ 75.26 December 31, 2024 926,465 73,906 $ 79.77 Total At-the-Market Equity Program 1,215,868 95,686 $ 78.70 Equity Forward Agreement December 29, 2023 1,400,000 107,095 $ 76.50 December 31, 2024 600,000 45,898 $ 76.50 Total Equity Forward Agreement 2,000,000 152,993 $ 76.50 Total forward sale agreements 3,215,868 $ 248,679 $ 77.33

ACCUMULATED OTHER COMPREHENSI_2

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Tables)	6 Months Ended
	Jun. 30, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]	The following table sets forth the effect of reclassifications from accumulated other comprehensive loss in our consolidated statements of income for the periods indicated: Three Months Ended Six Months Ended Affected Line Item in the Details About Accumulated Other June 30, June 30, Consolidated Statements Comprehensive Loss Components 2023 2022 2023 2022 of Income ( Thousands of dollars ) Pension and other postemployment benefit plan obligations (a) Amortization of net loss $ 490 $ 4,252 $ 980 $ 12,453 Amortization of unrecognized prior service cost (credit) 131 72 262 82 621 4,324 1,242 12,535 Regulatory adjustments (b) (621) (4,265) (1,242) (12,388) — 59 — 147 Income before income taxes — (15) — (34) Income tax expense Total reclassifications for the period $ — $ 44 $ — $ 113 Net income (a) These components of accumulated other comprehensive loss are included in the computation of net periodic benefit cost. See Note 9 for additional detail of 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 3 for additional disclosures of regulatory assets and liabilities.

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	6 Months Ended
	Jun. 30, 2023
EARNINGS PER SHARE [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: Three Months Ended June 30, 2023 Income Shares Per Share ( Thousands, except per share amounts ) Basic EPS Calculation Net income available for common stock $ 32,689 55,566 $ 0.59 Diluted EPS Calculation Effect of dilutive securities — 348 Net income available for common stock and common stock equivalents $ 32,689 55,914 $ 0.58 Three Months Ended June 30, 2022 Income Shares Per Share ( Thousands, except per share amounts ) Basic EPS Calculation Net income available for common stock $ 32,075 54,262 $ 0.59 Diluted EPS Calculation Effect of dilutive securities — 73 Net income available for common stock and common stock equivalents $ 32,075 54,335 $ 0.59 Six Months Ended June 30, 2023 Income Shares Per Share ( Thousands, except per share amounts ) Basic EPS Calculation Net income available for common stock $ 135,310 55,552 $ 2.43 Diluted EPS Calculation Effect of dilutive securities — 305 Net income available for common stock and common stock equivalents $ 135,310 55,857 $ 2.42 Six Months Ended June 30, 2022 Income Shares Per Share ( Thousands, except per share amounts ) Basic EPS Calculation Net income available for common stock $ 131,009 54,092 $ 2.42 Diluted EPS Calculation Effect of dilutive securities — 91 Net income available for common stock and common stock equivalents $ 131,009 54,183 $ 2.42

EMPLOYEE BENEFIT PLANS (Tables)

EMPLOYEE BENEFIT PLANS (Tables)	6 Months Ended
	Jun. 30, 2023
Employee Benefit Plans [Line Items]
Schedule of Net Benefit Costs [Table Text Block]	The following tables set forth the components of net periodic benefit cost for our pension and other postemployment benefit plans for the periods indicated: Pension Benefits Three Months Ended Six Months Ended June 30, June 30, 2023 2022 2023 2022 (Thousands of dollars) Components of net periodic benefit cost (credit) Service cost $ 1,811 $ 2,592 $ 3,622 $ 5,686 Interest cost 10,607 9,037 21,214 16,841 Expected return on assets (14,879) (14,632) (29,758) (29,245) Amortization of unrecognized prior service cost 93 62 186 62 Amortization of net loss 502 4,198 1,004 12,345 Net periodic benefit cost (credit) $ (1,866) $ 1,257 $ (3,732) $ 5,689 Other Postemployment Benefits Three Months Ended Six Months Ended June 30, June 30, 2023 2022 2023 2022 ( Thousands of dollars ) Components of net periodic benefit cost (credit) Service cost $ 183 $ 318 $ 366 $ 636 Interest cost 2,288 1,612 4,576 3,224 Expected return on assets (2,432) (3,295) (4,864) (6,590) Amortization of unrecognized prior service cost 38 10 76 20 Amortization of net (gain) loss (12) 54 (24) 108 Net periodic benefit cost (credit) $ 65 $ (1,301) $ 130 $ (2,602)

OTHER INCOME AND OTHER EXPENS_2

OTHER INCOME AND OTHER EXPENSE (Tables)	6 Months Ended
	Jun. 30, 2023
Schedule of Other Nonoperating Income (Expense)	The following table sets forth the components of other income and other expense for the periods indicated: Three Months Ended Six Months Ended June 30, June 30, 2023 2022 2023 2022 ( Thousands of dollars ) Net periodic benefit credit other than service cost $ 963 $ 1,366 $ 1,871 $ 778 Earnings (losses) on investments associated with nonqualified employee benefit plans 1,274 (4,619) 2,887 (7,452) Other, net (63) (730) (3) (1,454) Total other income (expense), net $ 2,174 $ (3,983) $ 4,755 $ (8,128)

DERIVATIVE FINANCIAL INSTRUME_3

DERIVATIVE FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS (Tables)	6 Months Ended
	Jun. 30, 2023
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair Value Measurements, Recurring and Nonrecurring	The following tables summarize, by level within the fair value hierarchy, our derivative and other assets and liabilities that were accounted for at fair value on a recurring basis at June 30, 2023 and December 31, 2022: June 30, 2023 Level 1 Level 2 Netting (c) Total (Thousands of dollars) Assets: Derivative instruments - swaps (a) $ — $ 616 $ (616) $ — Derivative instruments - options (a) — 452 — 452 United States treasury notes (b) 4,020 — — 4,020 Corporate bonds (b) — 9,544 — 9,544 Total assets $ 4,020 $ 10,612 $ (616) $ 14,016 Liabilities: Derivative instruments - swaps (a) $ — $ 3,747 $ (616) $ 3,131 December 31, 2022 Level 1 Level 2 Total (Thousands of dollars) Assets: United States treasury notes (b) $ 4,695 $ — $ 4,695 Corporate bonds (b) — 9,710 9,710 Total assets $ 4,695 $ 9,710 $ 14,405

VARIABLE INTEREST ENTITES (Tabl

VARIABLE INTEREST ENTITES (Tables)	6 Months Ended
	Jun. 30, 2023
Kansas Gas Service Securitization I LLC
Variable Interest Entity [Line Items]
Schedule of Variable Interest Entities	The following table summarizes the impact of KGSS-I on our consolidated balance sheets, for the periods indicated: June 30, December 31, 2023 2022 (Thousands of dollars) Restricted cash and cash equivalents $ 32,006 $ 8,446 Accounts receivable 3,157 4,862 Securitized intangible asset, net 309,569 323,838 Current maturities of securitized utility tariff bonds 34,201 20,716 Accounts payable 1,483 3,204 Accrued interest 11,418 2,202 Securitized utility tariff bonds, excluding current maturities, net of $5.9 million of discounts and issuance costs 295,949 309,343 Equity 1,681 1,681 The following table summarizes the impact of KGSS-I on our consolidated statements of income, for the period indicated: Three Months Ended Six Months Ended June 30, 2023 June 30, 2023 (Thousands of dollars) Operating revenues $ 11,807 $ 23,740 Operating expense (109) (219) Amortization expense (7,180) (14,269) Interest income 226 301 Interest expense (4,744) (9,553) Income before income taxes $ — $ —

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) number in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Significant Accounting Policies [Line Items]
Number of natural gas distribution services customers	2.3
Segment Reporting, Disclosure of Major Customers	no	no
Capital Expenditures Incurred but Not yet Paid	$ 7.9	$ 7.8
Allowance for Doubtful Accounts, Premiums and Other Receivables	$ 17		$ 16.7

REVENUE (Details)

REVENUE (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Regulated Operating Revenue, Gas	$ 393,876	$ 426,420	$ 1,416,593	$ 1,392,389
Regulated Operating Revenue, Other	4,238	2,555	13,664	8,045
Regulated Operating Revenue	398,114	428,975	1,430,257	1,400,434
Unbilled Receivables, Current	64,500		64,500		$ 269,500
Natural gas sales to customers [Member]
Regulated Operating Revenue, Gas	346,734	393,292	1,313,093	1,318,449
Transportation revenues [Member]
Regulated Operating Revenue, Gas	29,022	28,000	67,549	64,316
Securitization Customer Charges
Regulated Operating Revenue, Gas	11,807	0	23,740	0
Miscellaneous revenues [Member]
Regulated Operating Revenue, Gas	6,313	5,128	12,211	9,624
Other revenues - natural gas sales related [Member]
Regulated Operating Revenue, Other	1,614	(115)	7,404	2,231
Other revenues [Member]
Regulated Operating Revenue, Other	$ 2,624	$ 2,670	$ 6,260	$ 5,814

REGULATORY ASSETS AND LIABILI_3

REGULATORY ASSETS AND LIABILITIES (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022	Feb. 28, 2021
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	$ 64,912		$ 64,912		$ 275,572
Regulatory Assets, Noncurrent	304,614		304,614		330,831
Regulatory Assets	369,526		369,526		606,403
Regulatory Liability, Current	(79,686)		(79,686)		(47,867)
Regulatory Liability, Noncurrent	(512,633)		(512,633)		(529,441)
Regulatory Liabilities	(592,319)		(592,319)		(577,308)
Net regulatory assets (liabilities), current	(14,774)		(14,774)		227,705
Net regulatory assets (liabilities), noncurrent	(208,019)		(208,019)		(198,610)
Net Regulatory Assets	(222,793)		(222,793)		29,095
February 2021 Natural Gas Purchases						$ 2,100,000
TGS Proceeds from Securitization Bonds			197,000
Amortization of Rate Deferral	2,500	$ 1,600	9,500	$ 6,000
West Texas Service Area
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
TGS Deferred Extraordinary Costs from 2021 Winter Storm Uri	31,200		31,200
Pension and postretirement benefit costs [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Liability, Current					(8,228)
Regulatory Liability, Noncurrent					0
Regulatory Liabilities					(8,228)
Income tax rate changes [Member] [Domain]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Liability, Current	0		0		0
Regulatory Liability, Noncurrent	(512,633)		(512,633)		(529,441)
Regulatory Liabilities	(512,633)		(512,633)		(529,441)
Over-recovered purchased-gas costs [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Liability, Current	(79,686)		(79,686)		(39,639)
Regulatory Liability, Noncurrent	0		0		0
Regulatory Liabilities	(79,686)		(79,686)		(39,639)
Winter weather event costs
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	22,633		22,633		221,926
Regulatory Assets, Noncurrent	26,117		26,117		36,291
Regulatory Assets	48,750		48,750		258,217
Under-recovered purchased-gas costs [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current					19,755
Regulatory Assets, Noncurrent					0
Regulatory Assets					19,755
Pension and postretirement benefit costs [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	4,603		4,603		0
Regulatory Assets, Noncurrent	239,975		239,975		258,257
Regulatory Assets	244,578		244,578		258,257
Reacquired debt costs [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	812		812		812
Regulatory Assets, Noncurrent	2,985		2,985		3,347
Regulatory Assets	3,797		3,797		4,159
MGP Costs [Member] [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	98		98		98
Regulatory Assets, Noncurrent	31,891		31,891		29,743
Regulatory Assets	31,989		31,989		29,841
Ad valorem tax [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	12,125		12,125		13,359
Regulatory Assets, Noncurrent	0		0		0
Regulatory Assets	12,125		12,125		13,359
Weather normalization [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	7,809		7,809		8,474
Regulatory Assets, Noncurrent	0		0		0
Regulatory Assets	7,809		7,809		8,474
Customer credit deferrals
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	13,820		13,820		9,504
Regulatory Assets, Noncurrent	0		0		0
Regulatory Assets	13,820		13,820		9,504
Other regulatory assets [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	3,012		3,012		1,644
Regulatory Assets, Noncurrent	3,646		3,646		3,193
Regulatory Assets	$ 6,658		$ 6,658		$ 4,837

CREDIT FACILITIES (Details)

CREDIT FACILITIES (Details) $ in Thousands	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,000,000
Line of Credit Facility Sublimit	20,000
Line of Credit Facility Option to Increase Borrowing Capacity	$ 500,000
Approved Debt to Capital Ratio	0.70
Ratio of Indebtedness to Net Capital	0.52
Commercial paper maximum borrowing capacity	$ 1,000,000
Commercial Paper	$ 217,100	$ 552,000
Short-Term Debt, Weighted Average Interest Rate, at Point in Time	5.43%	4.75%
Letters of Credit Outstanding, Amount	$ 1,200
Line of Credit Facility, Remaining Borrowing Capacity	$ 998,800

LONG-TERM DEBT (Details)

LONG-TERM DEBT (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount	$ (7,422)	$ (7,636)
Debt Issuance Costs, Net	(19,571)	(20,143)
Long-Term Debt and Lease Obligation, Including Current Maturities	2,683,251	2,682,471
Current maturities of securitized utility tariff bonds	34,201	20,716
Long-term Debt, Current Maturities	772,838	12
Long-term Debt, excluding current maturities	1,876,212	2,661,743
Debt Instrument, Covenant Compliance, Default Provision, Indebtnedness Threshold	$ 100,000
Debt Instrument, Covenant Compliance, Default Provision, Debt Holders	25%
Debt Instrument, Redemption Price, Percentage	100%
3.61% Senior Unsecured Notes Due 2024
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.61%
Long-term Debt, Gross	$ 300,000	300,000
1.10% Senior Unsecured Notes Due 2024
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.10%
Long-term Debt, Gross	$ 473,000	473,000
2.00% Senior Unsecured Notes Due 2024
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2%
Long-term Debt, Gross	$ 300,000	300,000
4.25% Senior Unsecured Notes Due 2032
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.25%
Long-term Debt, Gross	$ 300,000	300,000
4.658% Senior Unsecured Notes Due 2044
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.658%
Long-term Debt, Gross	$ 600,000	600,000
4.50% Senior Unsecured Notes Due 2048
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.50%
Long-term Debt, Gross	$ 400,000	400,000
Total Senior Unsecured Notes
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 2,373,000	2,373,000
5.486% KGSS-I Securitized Utility Tariff Bonds Due 2032
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.486%
Long-term Debt, Gross	$ 336,000	336,000
Debt Issuance Costs, Net	(5,800)
Current maturities of securitized utility tariff bonds	$ 34,201	20,716
8.00% Other Long Term Debt
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	8%
Long-term Debt, Gross	$ 1,244	$ 1,250

EQUITY (Details)

EQUITY (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended					6 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Common stock issued, value		$ 6,661	$ 435	$ 5,636	$ 34,140
Proceeds from Issuance of Common Stock						$ 3,175	$ 37,104
Forward Contract Indexed to Issuer's Equity, Indexed Shares		3,215,868				3,215,868
Forward Contract Indexed to Equity, Settlement, Cash, Amount		$ 248,679				$ 248,679
Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share						$ 77.33
Common Stock, Dividends, Per Share, Declared		$ 0.65		$ 0.62		$ 1.30	$ 1.24
Subsequent Event [Member]
Common Stock, Dividends, Per Share, Declared	$ 0.65
Common Stock, Dividends, Declared, Annualized Basis	$ 2.60
Dividends Payable, Date of Record	Aug. 16, 2023
Dividends Payable, Date to be Paid	Sep. 01, 2023
At-The-Market Program
Aggregate Offering Price Limit		$ 300,000				$ 300,000
Common stock issued, shares							403,792
Common stock issued, value							$ 35,000
Proceeds from Issuance of Common Stock							$ 34,700
Equity Available for Issuance		$ 226,100				$ 226,100
Forward Contract Indexed to Issuer's Equity, Indexed Shares		1,215,868				1,215,868
Forward Contract Indexed to Equity, Settlement, Cash, Amount		$ 95,686				$ 95,686
Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share						$ 78.70
At-The-Market Program | December 29, 2023
Forward Contract Indexed to Issuer's Equity, Indexed Shares		289,403				289,403
Forward Contract Indexed to Equity, Settlement, Cash, Amount		$ 21,780				$ 21,780
Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share						$ 75.26
At-The-Market Program | December 31, 2024
Forward Contract Indexed to Issuer's Equity, Indexed Shares		926,465				926,465
Forward Contract Indexed to Equity, Settlement, Cash, Amount		$ 73,906				$ 73,906
Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share						$ 79.77
At-The-Market Program | December 30, 2022
Common stock issued, shares							591,736
Proceeds from Issuance of Common Stock							$ 48,000
March 2023 Equity Forward Agreement
Forward Contract Indexed to Issuer's Equity, Indexed Shares		2,000,000				2,000,000
Forward Contract Indexed to Equity, Settlement, Cash, Amount		$ 152,993				$ 152,993
Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share						$ 76.50
March 2023 Equity Forward Agreement | December 29, 2023
Forward Contract Indexed to Issuer's Equity, Indexed Shares		1,400,000				1,400,000
Forward Contract Indexed to Equity, Settlement, Cash, Amount		$ 107,095				$ 107,095
Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share						$ 76.50
March 2023 Equity Forward Agreement | December 31, 2024
Forward Contract Indexed to Issuer's Equity, Indexed Shares		600,000				600,000
Forward Contract Indexed to Equity, Settlement, Cash, Amount		$ 45,898				$ 45,898
Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share						$ 76.50

ACCUMULATED OTHER COMPREHENSI_3

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of net (gain) loss	$ 490	$ 4,252	$ 980	$ 12,453
Amortization of unrecognized prior service cost	131	72	262	82
Reclassification adjustment, before tax and regulatory adjustments	621	4,324	1,242	12,535
Regulatory adjustments	(621)	(4,265)	(1,242)	(12,388)
Reclassification adjustment, before tax	0	59	0	147
Reclassification adjustment, Tax	0	(15)	0	(34)
Reclassification adjustment, net of tax	$ 0	$ 44	$ 0	$ 113

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Basic EPS Calculation
Net income available for common stock	$ 32,689	$ 102,621	$ 32,075	$ 98,934	$ 135,310	$ 131,009
Weighted Average Number of Shares Outstanding, Basic	55,566		54,262		55,552	54,092
Earnings Per Share, Basic	$ 0.59		$ 0.59		$ 2.43	$ 2.42
Diluted EPS Calculation
Net Income (Loss) Available to Common Stockholders, Diluted	$ 32,689		$ 32,075		$ 135,310	$ 131,009
Effect of dilutive securities on shares	348		73		305	91
Weighted Average Number of Shares Outstanding, Diluted	55,914		54,335		55,857	54,183
Earnings Per Share, Diluted	$ 0.58		$ 0.59		$ 2.42	$ 2.42

EMPLOYEE BENEFIT PLANS (Details

EMPLOYEE BENEFIT PLANS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Components of net periodic benefit cost:
Amortization of unrecognized prior service cost	$ (131)	$ (72)	$ (262)	$ (82)
Amortization of net (gain) loss	(490)	(4,252)	(980)	(12,453)
Capitalized non-service cost components as a regulatory asset					$ 2,800
ONE Gas Pension Plans [Member]
Components of net periodic benefit cost:
Service cost	1,811	2,592	3,622	5,686
Interest cost	10,607	9,037	21,214	16,841
Expected return on assets	(14,879)	(14,632)	(29,758)	(29,245)
Amortization of unrecognized prior service cost	93	62	186	62
Amortization of net (gain) loss	502	4,198	1,004	12,345
Net periodic benefit cost	(1,866)	1,257	(3,732)	5,689
ONE Gas Postretirement Benefit Plans [Member]
Components of net periodic benefit cost:
Service cost	183	318	366	636
Interest cost	2,288	1,612	4,576	3,224
Expected return on assets	(2,432)	(3,295)	(4,864)	(6,590)
Amortization of unrecognized prior service cost	38	10	76	20
Amortization of net (gain) loss	(12)	54	(24)	108
Net periodic benefit cost	$ 65	$ (1,301)	$ 130	$ (2,602)

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Reduction in income tax expense for the amortization of the regulatory liability associated with excess ADIT that was returned to customers	$ 3.1	$ 3	$ 13	$ 10.9

OTHER INCOME AND OTHER EXPENS_3

OTHER INCOME AND OTHER EXPENSE (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Other Nonoperating Income (Expense)	$ 2,174	$ (3,983)	$ 4,755	$ (8,128)
Net periodic cost other than service cost [Member]
Other Nonoperating Income (Expense)	963	1,366	1,871	778
Earnings (losses) on investments associated with nonqualified employee benefit plans [Member]
Other Nonoperating Income (Expense)	1,274	(4,619)	2,887	(7,452)
Other, net [Member]
Other Nonoperating Income (Expense)	$ (63)	$ (730)	$ (3)	$ (1,454)

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES (Details) $ in Millions	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Commitments and Contingencies [Line Items]
Number Of Former Manufactured Gas Sites Where We Own Or Retain Legal Responsibility For Environmental Conditions	12
Number of sites where regulatory closure has been achieved	5
Deferred MGP Costs, Maximum	$ 15
Regulatory Asset for Costs Associated with Manufactured Gas Sites	$ 32	$ 32
Number of sites with ongoing groundwater monitoring	7
Accrual for Environmental Loss Contingencies	$ 14.8	$ 12.7

DERIVATIVE FINANCIAL INSTRUME_4

DERIVATIVE FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS (Details) Table - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Other Current Assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	$ 14,016	$ 14,405
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	(616)
Other Current Assets | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	4,020	4,695
Other Current Assets | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	10,612	9,710
Other Current Assets | Swap
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	0
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	(616)
Other Current Assets | Swap | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	0
Other Current Assets | Swap | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	616
Other Current Assets | Commodity Option
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	452
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	0
Other Current Assets | Commodity Option | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	0
Other Current Assets | Commodity Option | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	452
Other Assets | US Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	4,020	4,695
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	0
Other Assets | US Treasury Securities | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	4,020	4,695
Other Assets | US Treasury Securities | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	0	0
Other Assets | Corporate Bond Securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	9,544	9,710
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	0
Other Assets | Corporate Bond Securities | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	0	0
Other Assets | Corporate Bond Securities | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	9,544	$ 9,710
Other Current Liabilities | Swap
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Financial Instruments, Owned, at Fair Value	3,131
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	(616)
Other Current Liabilities | Swap | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Financial Instruments, Owned, at Fair Value	0
Other Current Liabilities | Swap | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Financial Instruments, Owned, at Fair Value	$ 3,747

DERIVATIVE FINANCIAL INSTRUME_5

DERIVATIVE FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS (Details) Note $ in Millions	6 Months Ended
	Jun. 30, 2023 USD ($) Bcf	Dec. 31, 2022 USD ($) Bcf
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Premiums recorded in other current assets on natural gas contracts held	$ 0.8	$ 14.1
Fair Value Assets, Transfers between Levels	$ 0
Swap
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative, Nonmonetary Notional Amount | Bcf	7.7
Commodity Option
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative, Nonmonetary Notional Amount | Bcf	0.7	19.4
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Long-term Debt, Fair Value	$ 2,500

VARIABLE INTEREST ENTITES (Deta

VARIABLE INTEREST ENTITES (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Variable Interest Entity [Line Items]
Restricted Cash and Cash Equivalents	$ 32,006	$ 32,006		$ 8,446
Accounts receivable, net	234,409	234,409		553,834
Current maturities of securitized utility tariff bonds	34,201	34,201		20,716
Accounts payable	154,121	154,121		360,493
Stockholders' Equity Attributable to Parent	2,654,826	2,654,826	$ 2,651,480	2,584,426	$ 2,453,596	$ 2,449,390	$ 2,349,532
Kansas Gas Service Securitization I LLC
Variable Interest Entity [Line Items]
Restricted Cash and Cash Equivalents	32,006	32,006		8,446
Accounts receivable, net	3,157	3,157		4,862
Finite-Lived Intangible Assets, Net	309,569	309,569		323,838
Current maturities of securitized utility tariff bonds	34,201	34,201		20,716
Accounts payable	1,483	1,483		3,204
Interest Payable	11,418	11,418		2,202
Securitized utility tariff bonds	295,949	295,949		309,343
Stockholders' Equity Attributable to Parent	1,681	1,681		$ 1,681
Forward Contract Indexed to Equity, Settlement, Cash, Amount	11,807	23,740
Utilities Operating Expense	(109)	(219)
Depreciation and amortization	(7,180)	(14,269)
Interest Income, Other	226	301
Interest Expense	(4,744)	(9,553)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	$ 0	$ 0