Summary of Significant Accounting Policies - Summary of Revenue Disaggregated by Type (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation Of Revenue [Line Items]
Total revenues	$ 155,540	$ 103,622	$ 297,037	$ 213,814
Natural Gas Sales [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	94,364	54,409	176,189	112,892
NGL Sales [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	19,393	18,702	40,641	38,446
Oil Sales [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	29,672	30,146	58,427	62,103
Brokered Natural Gas and Marketing Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	11,989	$ 365	21,519	$ 373
Other Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	$ 122		$ 261