Summary of Significant Accounting Policies - Summary of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accrued Liabilities Current [Abstract]
Ad valorem and production taxes	$ 4,299	$ 4,519
Employee compensation	8,667	4,257
Royalties	9,660	8,557
Short term derivatives	14,876	35,409
Other	4,160	2,302
Total accrued liabilities	$ 41,662	$ 55,044	$ 10,758