Supplemental Information on Oil and Gas Producing Activities (Unaudited) - Discounted future cash flows (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Oil and gas reserves
Future cash inflows computation period	12 months
Discount rate for annual net cash inflows (as a percent)	10.00%	10.00%	10.00%
Annual net cash inflows
Period of unweighted first day of the month average prices used to compute future cash inflows	12 months
Future cash inflows	$ 58,061	$ 109,052	$ 74,622
Future production costs	(41,887)	(39,378)	(34,665)
Future development costs	(2,027)	(2,073)	(1,704)
Future net cash flows before income tax	14,147	67,601	38,253
Future income tax expense	(2,178)	(13,692)	(7,813)
Future net cash flows	11,969	53,909	30,440
10% annual discount for estimated timing of cash flows	(6,874)	(30,345)	(17,007)
Standardized measure of discounted future net cash flows	5,095	23,564	13,433	$ 1,210
VIE, Martica
Annual net cash inflows
Standardized measure of discounted future net cash flows	$ 170	$ 458	$ 501