Summary of Significant Accounting Policies - Summary of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Accrued Liabilities, Current [Abstract]
Accrued drilling costs	$ 4,492	$ 26,269
Accrued interest	23,796	9,011
Accrued ad valorem taxes	4,500
Current deferred income taxes payable	460
Accrued rig termination fees		2,600
Other accrued liabilities	6,516	6,962
Total accrued expenses	$ 39,764	$ 44,842