XML 47 R35.htm IDEA: XBRL DOCUMENT
v3.23.1

Summary of Significant Accounting Policies - Oil and natural gas properties (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2023 | Mar. 31, 2022
Accounting Policies [Abstract] |  |
Depletion and accretion recognized | $ 33.8 | $ 16.1

X
- Definition The noncash expense charged against earnings to recognize the consumption of oil and gas reserves that are part of an entities' assets. + References No definition available. + Details
Name: | grnt_DepletionAndAccretionRecognized
Namespace Prefix: | grnt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration