Commitments and Contingencies - Additional Information (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2017 USD ($)
Commitments And Contingencies Disclosure [Abstract]
Natural gas transportation and treating agreements	through July 2019
Maximum commitments under natural gas transportation and treating agreements	$ 3.3
Contract term related to drilling rigs	through April 2018
Commitments for contracted drilling services	$ 9.9