Organization and Summary of Significant Accounting Policies - Components of Inventories (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Tubular goods and equipment	$ 15,633	$ 15,659
Crude oil	78,518	86,520
Total	$ 94,151	$ 102,179