Related Party Transactions - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Former Chairman, President and Chief Executive Officer [Member]
Related Party Transaction [Line Items]
Flight charter services fees	$ 0	$ 200,000		$ 300,000
Maximum [Member] | Former Chairman, President and Chief Executive Officer [Member]
Related Party Transaction [Line Items]
Flight charter services fees			$ 100,000
EnCap and Affiliates [Member] | Montage Resources Corporation [Member]
Related Party Transaction [Line Items]
Percentage of ownership interest	40.00%		40.00%