Summary of Significant Accounting Policies - Summary of Revenue Disaggregated by Type (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation Of Revenue [Line Items]
Total revenues	$ 174,109	$ 163,295	$ 155,540	$ 141,497	$ 171,208	$ 130,123	$ 103,622	$ 110,192	$ 634,441	$ 515,145	$ 383,659
Natural Gas Sales [Member]
Disaggregation Of Revenue [Line Items]
Total revenues									361,318	274,239	241,379
NGL Sales [Member]
Disaggregation Of Revenue [Line Items]
Total revenues									84,552	86,152	64,109
Oil Sales [Member]
Disaggregation Of Revenue [Line Items]
Total revenues									145,829	138,202	74,690
Brokered Natural Gas and Marketing Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total revenues									42,274	$ 16,552	$ 3,481
Other Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total revenues									$ 468