Summary of Significant Accounting Policies - Changes in Company's Asset Retirement Obligation Liability (Detail) $ in Thousands	9 Months Ended
Sep. 30, 2020 USD ($)
Asset Retirement Obligation [Abstract]
Asset retirement obligations, beginning of period	$ 31,841
Accretion	2,245
Additional liabilities incurred	15
Obligation for wells drilled	181
Liabilities settled via plugging	(178)
Liabilities sold/disposed	(901)
Less: current ARO portion	(2,867)
Asset retirement obligations, end of period	$ 30,336

Asset retirement obligation liabilities, sold or disposed.

No definition available.

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- Definition

Asset Retirement Obligation Liability Wells Drilled

+ References

No definition available.

+ Details

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- Definition

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

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- Definition

Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848

+ Details

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Balance Type:	debit
Period Type:	duration

- Definition

Current portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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+ Details

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Period Type:	instant

- Definition

Amount of asset retirement obligations incurred during the period.

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+ Details

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- Definition

Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset.

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+ Details

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