Employee Benefit Plan, Description of Plan (Details) - EBP 002	12 Months Ended
Dec. 31, 2025 USD ($) Integer
EBP, Description of Plan and Accounting Change [Abstract]
EBP, Employer Contribution, Participant Compensation Matched, Percentage	6.00%
EBP, Contribution, Combined Employee and Employer, Maximum, Percentage	100.00%
EBP, Contribution, Combined Employee and Employer, Maximum, Amount	$ 70,000
EBP, Eligible Compensation, Maximum, Amount	$ 350,000
EBP, Investment, Employer, Common Stock, to Total Asset, Percentage	20.00%
EBP, Description of Plan [Line Items]
EBP, Participant Contribution, Pretax, Maximum Annual Compensation to Total Compensation, Percentage	75.00%
EBP, Participant Contribution, Pretax, Maximum Annual Compensation, Amount	$ 23,500
EBP, Investment, Employer, Common Stock, to Total Asset, Percentage	20.00%
EBP, Eligible Compensation, Maximum, Amount	$ 350,000
EBP, Contribution, Combined Employee and Employer, Maximum, Amount	$ 70,000
EBP, Contribution, Combined Employee and Employer, Maximum, Percentage	100.00%
EBP, Employer Contribution, Participant Compensation Matched, Percentage	6.00%
EBP, Participant Contribution, After-tax Maximum Annual Compensation To Total Compensation, Percentage	6.00%
EBP, Participant Contribution, Pre-tax Maximum Annual Catch-Up Compensation, Amount	$ 7,500
EBP, Participant Contribution, Pre-tax Maximum Annual Super Catch-Up Compensation, Amount	$ 11,250
EBP, Vesting Description	All contributions to the account of an eligible participant and income and earnings, if any, attributable to the account of the participant are immediately and fully vested for the benefit of that participant upon receipt by the Plan Trustee (subject to subsequent loss, if any, through a decline in the market value of investments).
EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount	$ 1,000
EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount	$ 50,000
EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage	50.00%
EBP, Participant Contribution, Automatic, Deferral Rate	6.00%
EBP, Participant Contribution, Minimum Age For Voluntary Catchup Contributions \| Integer	50
Minimum
EBP, Description of Plan [Line Items]
EBP, Asset Held for Investment, Participant Loan, Interest Rate	3.25%
Maximum
EBP, Description of Plan [Line Items]
EBP, Asset Held for Investment, Participant Loan, Interest Rate	8.50%
Participant Contributions \| Fully Corrected
EBP, Description of Plan [Line Items]
EBP, Schedule of Delinquent Participant Contribution, Transferred Late to Plan	$ 650,256
Late Contribution Interest Adjustment \| Fully Corrected
EBP, Description of Plan [Line Items]
EBP, Schedule of Delinquent Participant Contribution, Transferred Late to Plan	$ 883

EBP, Contribution, Combined Employee and Employer, Maximum, Amount

No definition available.

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- Definition

EBP, Contribution, Combined Employee and Employer, Maximum, Percentage

+ References

No definition available.

+ Details

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- Definition

Annual IRS compensation limit amount that is eligible to calculate contributions.

+ References

No definition available.

+ Details

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- Definition

EBP, Participant Contribution, After-tax Maximum Annual Compensation To Total Compensation, Percentage

+ References

No definition available.

+ Details

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- Definition

EBP, Participant Contribution, Minimum Age For Voluntary Catchup Contributions

+ References

No definition available.

+ Details

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- Definition

EBP, Participant Contribution, Pre-tax Maximum Annual Catch-Up Compensation, Amount

+ References

No definition available.

+ Details

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Namespace Prefix:	ogs_
Data Type:	xbrli:monetaryItemType
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Period Type:	duration

- Definition

EBP, Participant Contribution, Pre-tax Maximum Annual Super Catch-Up Compensation, Amount

+ References

No definition available.

+ Details

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Namespace Prefix:	ogs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

EBP, Vesting Description

+ References

No definition available.

+ Details

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- Definition

Schedule of Delinquent Participant Contribution, Transferred Late to Plan

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-SubTopic 205
-Topic 962
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

+ Details

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Period Type:	duration

- Definition

Percentage of participant compensation eligible for employer matching contribution for participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478873/962-325-55-17

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Percentage of investment in common stock of employer of participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)), to total plan assets.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-04(2)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of maximum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of maximum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow to total participant account balance.

+ References

+ Details

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- Definition

Amount of minimum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of eligible compensation contributed for participant automatically enrolled in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

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Namespace Prefix:	us-gaap-ebp_
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Balance Type:	na
Period Type:	duration

- Definition

Amount of maximum pretax annual compensation that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)), is permitted to contribute.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage of maximum pretax annual compensation that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)), is permitted to contribute to total pretax annual compensation.

+ References

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Interest rate on participant loan in schedule of asset held for investment of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-05(a)(Schedule I))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Employee Retirement Income Security Act of 1974
-Number 2520
-Section 103
-Subsection 10
-Paragraph b
-Subparagraph (1)(i)(D)
-Publisher DOL-EBSA

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