Summary of Significant Accounting Policies - Summary of Revenue Disaggregated by Type (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation Of Revenue [Line Items]
Total revenues	$ 163,295	$ 130,123	$ 460,332	$ 343,938
Natural Gas Sales [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	87,841	65,756	264,030	178,648
NGL Sales [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	20,200	25,074	60,841	63,520
Oil Sales [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	44,980	36,349	103,407	98,452
Brokered Natural Gas and Marketing Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	10,228	$ 2,944	31,747	$ 3,318
Other Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	$ 46		$ 307