Name:	ogs_Otherrevenuesnaturalgassalesrelated
Namespace Prefix:	ogs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The total amount of regulated operating revenues recognized during the period.

No definition available.

Name:	us-gaap_RegulatedOperatingRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The amount of regulated gas operating revenues recognized during the period.

No definition available.

Name:	us-gaap_RegulatedOperatingRevenueGas
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The amount of regulated other operating revenues recognized during the period.

No definition available.

Name:	us-gaap_RegulatedOperatingRevenueOther
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Amount received for services rendered and products shipped, but not yet billed, for non-contractual agreements due within one year or the normal operating cycle, if longer.

No definition available.

Name:	us-gaap_UnbilledReceivablesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Name:	ogs_REVENUEAxis=ogs_NaturalgassalestocustomersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ogs_REVENUEAxis=ogs_TransportationrevenuesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ogs_REVENUEAxis=ogs_MiscellaneousrevenuesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ogs_REVENUEAxis=ogs_OtherrevenuesnaturalgassalesrelatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: