Commitments and Contingencies - Additional Information (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2019 USD ($) integer agreement
Contingencies And Commitments [Line Items]
Reimbursement Obligation To Construct Gas Gathering And Processing Facilities | $	$ 4.7
Minimum Volume Commitment	1
Number of Firm Transportation Contracts | agreement	2
Number Of GTP Reimbursement Obligations	1
Number Of Other Commitments	1
Reimbursement Obligation, Reimbursement Period	1 year
Number Of Firm Pipeline Transportation Contracts	1