Derivative Instruments - Realized and Unrealized Gains and Losses on Derivative Instruments (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Non-cash gain (loss) on derivatives:
Non-cash gain (loss) on derivatives, net	$ 0	$ (14,186)
Loss on natural gas derivatives, net	0	(1,124)
Swap [Member] | Natural Gas [Member]
Cash received on derivatives:
Cash received (paid) on derivatives, net	0	7,645
Non-cash gain (loss) on derivatives:
Non-cash gain (loss) on derivatives, net	0	(8,704)
Collars | Natural Gas [Member]
Cash received on derivatives:
Cash received (paid) on derivatives, net	0	5,417
Non-cash gain (loss) on derivatives:
Non-cash gain (loss) on derivatives, net	0	(5,482)
Crude Oil and Natural Gas [Member]
Cash received on derivatives:
Cash received (paid) on derivatives, net	0	13,062
Non-cash gain (loss) on derivatives:
Non-cash gain (loss) on derivatives, net	0	(14,186)
Loss on natural gas derivatives, net	$ 0	$ (1,124)