Derivative Financial Instruments (Schedule of Notional Amounts and Estimated Fair Values of Commodity Derivative Positions) (Detail) bbl in Thousands, MMBTU in Thousands, $ in Thousands	Dec. 31, 2021 USD ($) MMBTU bbl	Dec. 31, 2020 USD ($) bbl MMBTU
Financial Institution Counterparties [Member] | Oil Commodity Derivative [Member]
Derivative Instruments [Line Items]
Oil/Natural Gas Derivative Assets Notional Amount | bbl	4,809	3,056
Oil/Natural Gas Derivative Assets, Estimated Fair Value	$ 14,721	$ 8,341
Oil/Natural Gas Derivative Liabilities Notional Amount | bbl	7,032	6,391
Oil/Natural Gas Derivative Liabilities, Estimated Fair Value	$ (73,594)	$ (32,112)
Financial Institution Counterparties [Member] | Natural Gas Commodity Derivative [Member]
Derivative Instruments [Line Items]
Oil/Natural Gas Derivative Assets Notional Amount | MMBTU	15,947	9,281
Oil/Natural Gas Derivative Assets, Estimated Fair Value	$ 4,143	$ 1,529
Oil/Natural Gas Derivative Liabilities Notional Amount | MMBTU	29,446	15,079
Oil/Natural Gas Derivative Liabilities, Estimated Fair Value	$ (21,249)	$ (3,265)
Customer Counterparties [Member] | Oil Commodity Derivative [Member]
Derivative Instruments [Line Items]
Oil/Natural Gas Derivative Assets Notional Amount | bbl	7,046	6,391
Oil/Natural Gas Derivative Assets, Estimated Fair Value	$ 74,437	$ 32,670
Oil/Natural Gas Derivative Liabilities Notional Amount | bbl	4,796	3,056
Oil/Natural Gas Derivative Liabilities, Estimated Fair Value	$ (14,294)	$ (8,264)
Customer Counterparties [Member] | Natural Gas Commodity Derivative [Member]
Derivative Instruments [Line Items]
Oil/Natural Gas Derivative Assets Notional Amount | MMBTU	29,446	17,636
Oil/Natural Gas Derivative Assets, Estimated Fair Value	$ 21,456	$ 3,451
Oil/Natural Gas Derivative Liabilities Notional Amount | MMBTU	15,947	6,724
Oil/Natural Gas Derivative Liabilities, Estimated Fair Value	$ (4,124)	$ (1,458)