Summary of Significant Accounting Policies - Other Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Prepaid drilling liability	$ 21,595	$ 12,683
Interest payable	5,445	8,606
Lease operating expense payable	13,857	14,100
Ad valorem taxes payable	776	518
Current portion of asset retirement obligations	1,288	193	$ 39
Other	12,369	8,193
Total other accrued liabilities	$ 55,330	$ 44,293