Selected Quarterly Financial Data (Unaudited) - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Selected Quarterly Financial Information [Line Items]
Goodwill impairment expense	$ 1,641,197	$ 0	$ 0	$ 0					$ 1,641,197	$ 0	$ 0
Unproved impairment expense	441,750	6,549	54,922	11,773	$ 217,544	$ 42,568	$ 5,193	$ 4,420	514,994	269,725	30,076
Impairment of proved properties and other	$ 0	$ 0	$ 15,302	$ 7,312	$ 0	63,679	$ 0	$ 0	$ 22,614	$ 63,679	$ 43,040
Oklahoma and Texas Properties
Selected Quarterly Financial Information [Line Items]
Impairment of proved properties and other						$ 63,700

The adjustment to expense previously capitalized costs of drilling exploratory wells when proved reserves are not found or when the entity obtains information that raises substantial doubt about the economic or operational viability of the project.

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