Risk concentrations (Details)	9 Months Ended
Sep. 30, 2022
Risk concentrations
Percentage of partnership wells operated by third party operating partners	100.00%

Percentage of partnership wells operated by third party operating partners.

No definition available.

Name:	grnt_PercentageOfPartnershipWellsOperatedByThirdPartyOperatingPartners
Namespace Prefix:	grnt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration