Supplemental Oil and Gas Information (Unaudited) - Schedule of Changes in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Reserves (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Extractive Industries [Abstract]
Beginning of year	$ 589,554	$ 2,911,987	$ 1,718,204
Sale of oil and natural gas produced, net of production costs	(107,357)	(128,382)	(354,932)
Purchase of minerals in place	0	75,998	1,489,477
Sale of minerals in place	(28,277)	(45,100)
Extensions and discoveries	2,016	18,582	44,843
Changes in income taxes, net	0	63,180	(63,180)
Changes in prices and costs	(404,870)	(2,764,481)	(170,682)
Previously estimated development costs incurred	89,748	322,446	275,078
Net changes in future development costs	254,043	448,089	(133,098)
Revisions of previous quantities	14,414	(344,775)	(48,087)
Accretion of discount	58,956	297,517	171,820
Change in production rates and other	(72,386)	(265,507)	(17,456)
End of year	$ 395,841	$ 589,554	$ 2,911,987