v3.26.1
Schedule H, Line 4i - Schedule of Assets (Held at End of Year) (Details) - EBP 002
$ in Thousands
12 Months Ended
Dec. 31, 2025
USD ($)
EBP, Schedule of Asset Held for Investment [Line Items]  
Entity tax identification number 73-1520922
Plan number 002
Participant loan, current value $ 28,038
Asset held for investment $ 1,722,913
Minimum  
EBP, Schedule of Asset Held for Investment [Line Items]  
Participant loan, interest rate 3.25%
Maximum  
EBP, Schedule of Asset Held for Investment [Line Items]  
Participant loan, interest rate 10.50%
Investment, Identifier [Axis]: Baird Core Plus Bond Fund Institutional Shares | Mutual Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments $ 17,111
Investment, Identifier [Axis]: Dodge & Cox International Stock Fund Class X | Mutual Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 30,026
Investment, Identifier [Axis]: Dodge & Cox Stock Fund Class X | Mutual Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 37,574
Investment, Identifier [Axis]: Fidelity Balanced K | Mutual Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 44,990
Investment, Identifier [Axis]: Fidelity Emerging Markets Index | Mutual Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 5,477
Investment, Identifier [Axis]: Invesco Stable Value Trust Class B1 | Collective Investment Trust  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 7,662
Investment, Identifier [Axis]: JPMorgan Large Cap Growth Fund Class R6 | Mutual Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 112,972
Investment, Identifier [Axis]: JPMorgan Small Cap Equity Fund Class R6 | Mutual Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 30,758
Investment, Identifier [Axis]: ONE Gas Inc. Stock | Common Stock  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 6,291
Investment, Identifier [Axis]: ONEOK, Inc. | Common Stock  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 220,727
Investment, Identifier [Axis]: Vanguard Cash Reserves Federal Money Market Fund Admiral Shares | Money Market Mutual Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 30,409
Investment, Identifier [Axis]: Vanguard Extended Market Index Fund Institutional Shares | Mutual Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 15,133
Investment, Identifier [Axis]: Vanguard FTSE All-World ex-US Index Fund Institutional Shares | Mutual Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 9,053
Investment, Identifier [Axis]: Vanguard Institutional Index Fund Plus | Mutual Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 162,374
Investment, Identifier [Axis]: Vanguard Primecap Fund Admiral Shares | Mutual Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 97,317
Investment, Identifier [Axis]: Vanguard Target Retirement 2020 Trust I | Collective Investment Trust  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 9,647
Investment, Identifier [Axis]: Vanguard Target Retirement 2025 Trust I | Collective Investment Trust  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 41,252
Investment, Identifier [Axis]: Vanguard Target Retirement 2030 Trust I | Collective Investment Trust  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 79,669
Investment, Identifier [Axis]: Vanguard Target Retirement 2035 Trust I | Collective Investment Trust  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 108,490
Investment, Identifier [Axis]: Vanguard Target Retirement 2040 Trust I | Collective Investment Trust  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 124,990
Investment, Identifier [Axis]: Vanguard Target Retirement 2045 Trust I | Collective Investment Trust  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 138,688
Investment, Identifier [Axis]: Vanguard Target Retirement 2050 Trust I | Collective Investment Trust  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 146,062
Investment, Identifier [Axis]: Vanguard Target Retirement 2055 Trust I | Collective Investment Trust  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 129,976
Investment, Identifier [Axis]: Vanguard Target Retirement 2060 Trust I | Collective Investment Trust  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 48,321
Investment, Identifier [Axis]: Vanguard Target Retirement 2065 Trust I | Collective Investment Trust  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 24,093
Investment, Identifier [Axis]: Vanguard Target Retirement 2070 Trust I | Collective Investment Trust  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 3,208
Investment, Identifier [Axis]: Vanguard Target Retirement Income Trust I | Collective Investment Trust  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments 3,237
Investment, Identifier [Axis]: Vanguard Total Bond Market Index Fund Institutional Shares | Mutual Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Total Investments $ 9,368