Commitments and Contingencies - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($)
Commitments And Contingencies Disclosure [Abstract]
Commitments for contracted drilling services	$ 1.3
Contract term related to drilling services	through November 2015
Natural gas transportation and treating agreements	through July 2019
Maximum commitments under natural gas transportation and treating agreements	$ 7.1