XML 43 R31.htm IDEA: XBRL DOCUMENT v3.23.1

Organization and nature of operations (Details) - USD ($)		1 Months Ended
	Oct. 24, 2022	Jan. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Basin acquisition that met the definition of a business combination
Common stock, shares authorized (in shares)			431,000,000	431,000,000
ENPC Common Class A
Basin acquisition that met the definition of a business combination
Common stock shares converted (in shares)	1
ENPC Common Class F
Basin acquisition that met the definition of a business combination
Common stock to be converted (in shares)	1
Executive Network Partnering Corporation
Basin acquisition that met the definition of a business combination
Business acquisition, cash consideration transferred	$ 396,100,000
Warrants to be converted (in shares)	1
Total aggregate investment by ENPC	$ 6,800,000
Executive Network Partnering Corporation | ENPC Common Class A
Basin acquisition that met the definition of a business combination
Common stock, shares authorized (in shares)	41,400,000
Common stock, shares outstanding (in shares)	39,343,496
Business acquisition, redemption price per share (in dollars per share)	$ 10.07
Executive Network Partnering Corporation | ENPC Common Class A | ENPC Conversion Activity, Effective Time of Merger
Basin acquisition that met the definition of a business combination
Shares converted during merger (in shares)	1,238,393
Converted shares subject to certain vesting provisions, forfeitures		$ 220,348
Converted shares subject to certain vesting provisions (in shares)				371,518
Executive Network Partnering Corporation | Common Class A
Basin acquisition that met the definition of a business combination
Shares issues to existing GREP members upon business combination closing (in shares)	130,000,000
Executive Network Partnering Corporation | ENPC Common Class F | ENPC Conversion Activity, Effective Time of Merger
Basin acquisition that met the definition of a business combination
Shares to-be converted during merger (in shares)	495,357
Shares forfeited (in shares)	220,348

X

- Definition

Number of shares of common stock converted from one class to another.

+ References

No definition available.

+ Details

Name:	grnt_CommonStockSharesConverted
Namespace Prefix:	grnt_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of shares of common stock converted from one class to another.

+ References

No definition available.

+ Details

Name:	grnt_CommonStockToBeConverted
Namespace Prefix:	grnt_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Number of shares of common stock converted from one class to another at the effective time of merger between GREP and ENCP, and are subject to certain vesting and forfeiture provisions set forth in the Company's Sponsor Agreement.

+ References

No definition available.

+ Details

Name:	grnt_ConvertedSharesSubjectToCertainVestingProvisions
Namespace Prefix:	grnt_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Number of shares of common stock converted from one class to another at the effective time of merger between GREP and ENCP.

+ References

No definition available.

+ Details

Name:	grnt_SharesConvertedDuringMerger
Namespace Prefix:	grnt_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Number of shares of common stock to be converted from one class to another at the effective time of merger between GREP and ENCP.

+ References

No definition available.

+ Details

Name:	grnt_SharesToBeConvertedDuringMerger
Namespace Prefix:	grnt_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Represents the information pertaining to Executive Network Partnering Corporation warrants.

+ References

No definition available.

+ Details

Name:	grnt_WarrantsToBeConverted
Namespace Prefix:	grnt_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- 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

No definition available.

+ Details

Name:	us-gaap_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessAcquisitionSharePrice
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_CommonStockSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21463-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_CommonStockSharesOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Amount of investment in equity method investee and investment in and advance to affiliate.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(18))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

X

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-URI https://asc.fasb.org/extlink&oid=126975305&loc=d3e6927-128479

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3213-108585

+ Details

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

X

- Definition

Value of forfeited shares granted under share-based payment arrangement. Excludes employee stock ownership plan (ESOP).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph c(2)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

Name:	us-gaap_StockGrantedDuringPeriodValueSharebasedCompensationForfeited
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Number of shares of stock issued during the period pursuant to acquisitions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI https://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesAcquisitions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of shares (or other type of equity) forfeited during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_StatementClassOfStockAxis=grnt_EnpcCommonClassMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementClassOfStockAxis=grnt_EnpcCommonClassFMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_BusinessAcquisitionAxis=grnt_ExecutiveNetworkPartneringCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ConversionOfStockByUniqueDescriptionAxis=grnt_CommonShareConversionActivityAtEffectiveTimeOfMergerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: