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Commitments and Contingencies - Additional Information (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Commitments And Contingencies Disclosure [Abstract]      
Rent expense under noncancelable operating leases $ 1.5 $ 1.5 $ 1.5
Commitments for contracted drilling services $ 2.8    
Contract term related to drilling rigs through April 2017    
Natural gas transportation and treating agreements through July 2019    
Maximum commitments under natural gas transportation and treating agreements $ 4.2