Supplemental Crude Oil and Natural Gas Information - Standardized Measure of Discounted Future Net Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Supplemental Crude Oil and Natural Gas Information [Abstract]
Discount factor utilized as standardized measure for future net cash flows	10.00%
Future cash inflows	$ 49,893,470	$ 61,510,432	$ 42,574,897
Future production costs	(15,309,672)	(16,139,001)	(11,159,362)
Future development and abandonment costs	(10,033,887)	(9,706,114)	(6,487,097)
Future income taxes	(3,351,657)	(6,012,439)	(3,488,755)
Future net cash flows	21,198,254	29,652,878	21,439,683
10% annual discount for estimated timing of cash flows	(10,736,613)	(13,968,061)	(10,969,506)
Standardized measure of discounted future net cash flows	$ 10,461,641	$ 15,684,817	$ 10,470,177	$ 5,510,223