Summary of Accounts Receivable (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Receivables [Abstract]
Customers	$ 22,920	$ 20,489
Joint interest partners	21,598	7,238
Other	670	3,789
Accounts Receivable, Gross, Current, Total	45,188	31,516
Less: Allowance for doubtful accounts	(2,381)	(2,421)
Accounts receivable, net of allowance for doubtful accounts	$ 42,807	$ 29,095