EBP Income Taxes EBP Income Taxes [Policy Text Block] EBP Income Taxes Statistical Measurement [Domain] Statistical Measurement [Domain] Party-in-Interest Transactions EBP, Related Party and Party-in-Interest Transactions [Text Block] Interest on notes receivable from participants EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Document Information [Line Items] Document Information [Line Items] EBP, Contribution, Combined Employee and Employer, Maximum, Percentage EBP, Contribution, Combined Employee and Employer, Maximum, Percentage EBP, Contribution, Combined Employee and Employer, Maximum, Percentage EBP, Schedule of Delinquent Participant Contribution, Corrected EBP, Schedule of Delinquent Participant Contribution, Corrected EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] EBP, Participant Contribution, After-tax Maximum Annual Compensation To Total Compensation, Percentage EBP, Participant Contribution, After-tax Maximum Annual Compensation To Total Compensation, Percentage EBP, Participant Contribution, After-tax Maximum Annual Compensation To Total Compensation, Percentage EBP, Participant Contribution, Receivable EBP, Participant Contribution, Receivable EBP, Description of Plan and Accounting Change [Abstract] Investment Type [Axis] Investment Type [Axis] Rollovers EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage EBP, Vesting Description EBP, Vesting Description EBP, Vesting Description EBP, Description of Plan [Line Items] EBP, Description of Plan [Line Items] EBP, Eligible Compensation, Maximum, Amount EBP, Eligible Compensation, Maximum, Amount Annual IRS compensation limit amount that is eligible to calculate contributions. EBP, Schedule of Asset Held for Investment [Table] EBP, Schedule of Asset Held for Investment [Table] EBP, Asset Held for Investment, Participant Loan, after Deemed Distribution EBP, Asset Held for Investment, Participant Loan, after Deemed Distribution Investments EBP, Investment, Fair Value and NAV [Text Block] Document Information, Document [Axis] Document Information, Document [Axis] EBP, Investment, Fair Value and NAV [Table] EBP, Investment, Fair Value and NAV [Table] EBP, Schedule of Delinquent Participant Contribution, Corrected Outside VFCP EBP, Schedule of Delinquent Participant Contribution, Corrected Outside VFCP EBP, Expense EBP, Expense [Policy Text Block] Total contributions EBP, Change in Net Asset Available for Benefit, Increase from Contribution EBP, Schedule of Asset Held for Investment EBP, Schedule of Asset Held for Investment [Text Block] EBP, Schedule of Asset Held for Investment Entity Registrant Plan Name Entity Registrant Plan Name Entity Registrant Plan Name EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount EBP, Contribution, Combined Employee and Employer, Maximum, Amount EBP, Contribution, Combined Employee and Employer, Maximum, Amount EBP, Contribution, Combined Employee and Employer, Maximum, Amount Money Market Funds [Member] Money Market Funds [Member] EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant Employer contributions EBP, Employer Contribution, Receivable Participants EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover EBP, Investment, Current Value, Type [Extensible Enumeration] EBP, Investment, Current Value, Type [Extensible Enumeration] EBP, Payment to Participant EBP, Payment to Participant [Policy Text Block] EBP, Net Asset Available for Benefit Net assets available for benefits, beginning of period EBP, Net Asset Available for Benefit Delinquent Participant Contributions [Domain] Delinquent Participant Contributions [Domain] Delinquent Participant Contributions [Domain] EBP Fair Value of Plan Assets EBP Fair Value of Plan Assets [Policy Text Block] EBP Fair Value of Plan Assets Participant Contributions Delinquent Participant Contributions [Member] Delinquent Participant Contributions EBP, Schedule of Asset Held for Investment [Line Items] EBP, Schedule of Asset Held for Investment [Line Items] EBP, Accounting Policy [Line Items] EBP, Accounting Policy [Line Items] EBP, Participant Contribution, Minimum Age For Voluntary Catchup Contributions EBP, Participant Contribution, Minimum Age For Voluntary Catchup Contributions EBP, Participant Contribution, Minimum Age For Voluntary Catchup Contributions Delinquent Participant Contributions [Axis] Delinquent Participant Contributions [Axis] Delinquent Participant Contributions EBP, Schedule of Delinquent Participant Contribution [Abstract] EBP, Participant Contribution, Pretax, Maximum Annual Compensation, Amount EBP, Participant Contribution, Pretax, Maximum Annual Compensation, Amount EBP, Participant Contribution, Automatic, Deferral Rate EBP, Participant Contribution, Automatic, Deferral Rate Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Net increase in net assets available for benefits EBP, Change in Net Asset Available for Benefit, Increase (Decrease) Cover [Abstract] Cover [Abstract] Maximum Maximum [Member] Employer EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash EBP, Schedule of Delinquent Participant Contribution, Pending Correction in VFCP EBP, Schedule of Delinquent Participant Contribution, Pending Correction in VFCP EBP, Participant Contribution, Pretax, Maximum Annual Compensation to Total Compensation, Percentage EBP, Participant Contribution, Pretax, Maximum Annual Compensation to Total Compensation, Percentage Minimum Minimum [Member] EBP, Schedule of Asset Held for Investment [Abstract] EBP, Schedule of Asset Held for Investment [Abstract] Dividends EBP, Change in Net Asset Available for Benefit, Increase from Dividend Income on Investment Entity [Domain] Entity [Domain] EBP, Schedule of Delinquent Participant Contribution EBP, Schedule of Delinquent Participant Contribution [Table Text Block] EBP, Asset Held for Investment EBP, Asset Held for Investment Investment, Identifier [Axis] Investment, Identifier [Axis] EBP, Schedule of Delinquent Participant Contribution, Not Corrected EBP, Schedule of Delinquent Participant Contribution, Not Corrected Delinquent Participant Contributions Correction Status [Axis] Delinquent Participant Contributions Correction Status [Axis] Delinquent Participant Contributions Correction Status EBP, Schedule of Delinquent Participant Contribution [Line Items] EBP, Schedule of Delinquent Participant Contribution [Line Items] EBP, Investment, Fair Value and NAV [Abstract] EBP, Basis of Accounting EBP, Basis of Accounting [Policy Text Block] Schedule H, Line 4a EBP, Schedule of Delinquent Participant Contribution [Text Block] EBP, Schedule of Delinquent Participant Contribution Document [Domain] Document [Domain] EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Statement of Change in Net Asset Available for Benefit [Table] Mutual Fund [Member] Mutual Fund [Member] EBP, Description of Plan [Table] EBP, Description of Plan [Table] EBP, Asset Held for Investment, Party-in-Interest [true false] EBP, Asset Held for Investment, Party-in-Interest [true false] EBP, Investment EBP, Investment [Policy Text Block] Amendment Flag Amendment Flag EBP 002 EBP 002 [Member] EBP 002 EBP, Participant Contribution, Pre-tax Maximum Annual Catch-Up Compensation, Amount EBP, Participant Contribution, Pre-tax Maximum Annual Catch-Up Compensation, Amount EBP, Participant Contribution, Pre-tax Maximum Annual Catch-Up Compensation, Amount EBP, Investment, Fair Value and NAV EBP, Investment, Fair Value and NAV [Table Text Block] EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Current Value EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Current Value EBP, Statement of Change in Net Asset Available for Benefit [Abstract] EBP, Related Party and Party-in-Interest Transactions [Abstract] EBP, Related Party and Party-in-Interest Transactions [Line Items] EBP, Related Party and Party-in-Interest Transactions [Line Items] Fully Corrected Fully Corrected [Member] Fully Corrected EBP, Schedule of Delinquent Participant Contribution, Transferred Late to Plan Schedule of Delinquent Participant Contribution, Transferred Late to Plan Schedule of Delinquent Participant Contribution, Transferred Late to Plan EBP, Statement of Net Asset Available for Benefit [Abstract] Description of Plan EBP, Description of Plan [Text Block] Summary of Significant Accounting Policies EBP, Summary of Accounting Policy [Text Block] Document Period End Date Document Period End Date EBP, Statement of Net Asset Available for Benefit [Line Items] EBP, Statement of Net Asset Available for Benefit [Line Items] Entity Central Index Key Entity Central Index Key Common Stock - ONE Gas, Inc. [Member] Common Stock - ONE Gas, Inc. [Member] Common Stock - ONE Gas, Inc. EBP, Asset Held for Investment, Participant Loan, Interest Rate EBP, Asset Held for Investment, Participant Loan, Interest Rate EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value Legal Entity [Axis] Legal Entity [Axis] Net investment income EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment Scenario [Domain] Scenario [Domain] Delinquent Participant Contributions Correction Status [Domain] Delinquent Participant Contributions Correction Status [Domain] Delinquent Participant Contributions Correction Status [Domain] EBP, Accounting Policy, Accounting Standard Update, and Change in Accounting Principle [Abstract] Scenario [Axis] Scenario [Axis] Contributions: EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] EBP, Investment, Issuer Name [Extensible Enumeration] EBP, Investment, Issuer Name [Extensible Enumeration] Document Type Document Type Fair Value, Inputs, Level 3 [Member] Fair Value, Inputs, Level 3 [Member] EBP, Statement of Net Asset Available for Benefit [Table] EBP, Statement of Net Asset Available for Benefit [Table] EBP, Investment, Fair Value and NAV [Line Items] EBP, Investment, Fair Value and NAV [Line Items] EBP, Use of Estimate EBP, Use of Estimate [Policy Text Block] Statistical Measurement [Axis] Statistical Measurement [Axis] Deductions to net assets attributed to: EBP, Change in Net Asset Available for Benefit, Decrease [Abstract] Notes receivable from participants EBP, Note Receivable from Participant Fair Value, Inputs, Level 2 Fair Value, Inputs, Level 2 [Member] EBP, Schedule of Asset Held for Investment EBP, Schedule of Asset Held for Investment [Table Text Block] EBP, Participant Contribution, Pre-tax Maximum Annual Super Catch-Up Compensation, Amount EBP, Participant Contribution, Pre-tax Maximum Annual Super Catch-Up Compensation, Amount EBP, Participant Contribution, Pre-tax Maximum Annual Super Catch-Up Compensation, Amount Net appreciation in fair value of investments EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Gain (Loss) on Investment EBP, Accounting Policy [Table] EBP, Accounting Policy [Table] Investments [Domain] Investments [Domain] Document Information [Table] Document Information [Table] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] Late Contribution Interest Adjustment Delinquent Contribution Interest Adjustment [Member] Delinquent Contribution Interest Adjustment Common Stock - ONEOK, Inc. [Member] Common Stock - ONEOK, Inc. [Member] Common Stock - ONEOK, Inc. Fair Value, Inputs, Level 1 Fair Value, Inputs, Level 1 [Member] Entity Registrant Name Entity Registrant Name Employee contributions EBP, Schedule of Delinquent Participant Contribution, Transferred Late to Plan Investment income: EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment [Abstract] EBP, Investment, Employer, Common Stock, to Total Asset, Percentage EBP, Investment, Employer, Common Stock, to Total Asset, Percentage EBP, Schedule of Delinquent Participant Contribution [Table] EBP, Schedule of Delinquent Participant Contribution [Table] Receivables: EBP, Receivable [Abstract] Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] EBP, Receivable EBP, Receivable EBP, Employer Contribution, Participant Compensation Matched, Percentage EBP, Employer Contribution, Participant Compensation Matched, Percentage Federated Hermes Government Obligations Fund [Member] Federated Hermes Government Obligations Fund Invesco Short-Term Investments Trust Government & Agency Portfolio Institutional Class [Member] Invesco Short-Term Investments Trust Government & Agency Portfolio Institutional Class American Funds 2010 Target Date Retirement Fund Class R6 [Member] American Funds 2010 Target Date Retirement Fund Class R6 American Funds 2015 Target Date Retirement Fund Class R6 [Member] American Funds 2015 Target Date Retirement Fund Class R6 American Funds 2020 Target Date Retirement Fund Class R6 [Member] American Funds 2020 Target Date Retirement Fund Class R6 American Funds 2025 Target Date Retirement Fund Class R6 [Member] American Funds 2025 Target Date Retirement Fund Class R6 American Funds 2030 Target Date Retirement Fund Class R6 [Member] American Funds 2030 Target Date Retirement Fund Class R6 American Funds 2035 Target Date Retirement Fund Class R6 [Member] American Funds 2035 Target Date Retirement Fund Class R6 American Funds 2040 Target Date Retirement Fund Class R6 [Member] American Funds 2040 Target Date Retirement Fund Class R6 American Funds 2045 Target Date Retirement Fund Class R6 [Member] American Funds 2045 Target Date Retirement Fund Class R6 American Funds 2050 Target Date Retirement Fund Class R6 [Member] American Funds 2050 Target Date Retirement Fund Class R6 American Funds 2055 Target Date Retirement Fund Class R6 [Member] American Funds 2055 Target Date Retirement Fund Class R6 American Funds 2060 Target Date Retirement Fund Class R6 [Member] American Funds 2060 Target Date Retirement Fund Class R6 American Funds 2065 Target Date Retirement Fund Class R6 [Member] American Funds 2065 Target Date Retirement Fund Class R6 Eaton Vance Atlanta Capital SMID-Cap Fund Class R6 [Member] Eaton Vance Atlanta Capital SMID-Cap Fund Class R6 American Funds American Mutual Fund Class R5E [Member] American Funds American Mutual Fund Class R5E Fidelity Balanced [Member] Fidelity Balanced Vanguard Primecap Fund Admiral Share [Member] Vanguard Primecap Fund Admiral Share JPMorgan Large Cap Growth Fund Class R6 [Member] JPMorgan Large Cap Growth Fund Class R6 Nomura Small Cap Value Fund Institutional Class [Member] Nomura Small Cap Value Fund Institutional Class MFS International Diversification Fund Class R3 [Member] MFS International Diversification Fund Class R3 Fidelity U.S. Bond Index Fund [Member] Fidelity U.S. Bond Index Fund Fidelity 500 Index Fund [Member] Fidelity 500 Index Fund Fidelity Global ex U.S. Index Fund [Member] Fidelity Global ex U.S. Index Fund Fidelity Mid Cap Index Fund [Member] Fidelity Mid Cap Index Fund Fidelity Small Cap Index Fund [Member] Fidelity Small Cap Index Fund JPMorgan Small Cap Equity Fund Class R5 [Member] JPMorgan Small Cap Equity Fund Class R5 Loomis Sayles Investment Grade Bond Fund Class A [Member] Loomis Sayles Investment Grade Bond Fund Class A ONE Gas, Inc. [Member] ONE Gas, Inc. Common Stock [Member] ONEOK, Inc. [Member] ONEOK, Inc.