Derivative Financial Instruments - Schedule of Notional Amounts and Estimated Fair Values of Commodity Derivative Positions (Detail) bbl in Thousands, MMBTU in Thousands, $ in Thousands	Jun. 30, 2021 USD ($) MMBTU bbl	Dec. 31, 2020 USD ($) MMBTU bbl
Financial Institution Counterparties [Member] | Oil Commodity Derivative [Member]
Derivative Instruments [Line Items]
Oil/Natural Gas Derivative Assets, Notional Amount | bbl	4,404	3,056
Oil/Natural Gas Derivative Liabilities, Notional Amount | bbl	10,187	6,391
Oil/Natural Gas Derivative Assets, Estimated Fair Value	$ 8,102	$ 8,341
Oil/Natural Gas Derivative Liabilities, Estimated Fair Value	$ (133,830)	$ (32,112)
Financial Institution Counterparties [Member] | Natural Gas Commodity Derivative [Member]
Derivative Instruments [Line Items]
Oil/Natural Gas Derivative Assets, Notional Amount | MMBTU	15,562	9,281
Oil/Natural Gas Derivative Liabilities, Notional Amount | MMBTU	37,124	15,079
Oil/Natural Gas Derivative Assets, Estimated Fair Value	$ 2,715	$ 1,529
Oil/Natural Gas Derivative Liabilities, Estimated Fair Value	$ (18,752)	$ (3,265)
Customer Counterparties [Member] | Oil Commodity Derivative [Member]
Derivative Instruments [Line Items]
Oil/Natural Gas Derivative Assets, Notional Amount | bbl	10,258	6,391
Oil/Natural Gas Derivative Liabilities, Notional Amount | bbl	4,333	3,056
Oil/Natural Gas Derivative Assets, Estimated Fair Value	$ 134,834	$ 32,670
Oil/Natural Gas Derivative Liabilities, Estimated Fair Value	$ (8,094)	$ (8,264)
Customer Counterparties [Member] | Natural Gas Commodity Derivative [Member]
Derivative Instruments [Line Items]
Oil/Natural Gas Derivative Assets, Notional Amount | MMBTU	37,124	17,636
Oil/Natural Gas Derivative Liabilities, Notional Amount | MMBTU	15,562	6,724
Oil/Natural Gas Derivative Assets, Estimated Fair Value	$ 19,065	$ 3,451
Oil/Natural Gas Derivative Liabilities, Estimated Fair Value	$ (2,711)	$ (1,458)