Supplemental Oil and Natural Gas Information (unaudited) - Standardized Measure of Discounted Net Future Cash Flows (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Net Cash Flows [Abstract]
Future cash inflows (total revenues)	$ 8,212,521	$ 6,730,000	$ 4,750,238
Future production costs	(3,867,182)	(2,964,098)	(2,332,310)
Future development costs (capital costs)	(982,321)	(855,932)	(879,399)
Future income tax expense	(633,086)	(136,472)
Future net cash flows	2,729,932	2,773,498	1,538,529
10% annual discount for estimated timing of cash flows	(1,534,108)	(1,444,188)	(808,843)
Standardized measure of Discounted Future Net Cash Flow	$ 1,195,824	$ 1,329,310	$ 729,686	$ 205,981