Summary of Significant Accounting Policies - Summary of Revenue Disaggregated by Type (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation Of Revenue [Line Items]
Total revenues	$ 90,684	$ 155,540	$ 224,108	$ 297,037
Natural Gas Sales [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	65,586	94,364	144,678	176,189
NGL Sales [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	7,962	19,393	26,510	40,641
Oil Sales [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	9,534	29,672	35,765	58,427
Brokered Natural Gas and Marketing Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	7,540	11,989	17,028	21,519
Other Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	$ 62	$ 122	$ 127	$ 261