Supplemental Information on Oil and Gas Producing Activities (Unaudited) - Changes in standardized measure of discounted future net cash flow (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) $ / Mcfe	Dec. 31, 2022 USD ($) $ / Mcfe	Dec. 31, 2021 USD ($) $ / Mcfe
Oil and gas reserves
12-month weighted average price (in dollars per Mcfe | $ / Mcfe	3.20	6.14	4.21
Changes in Standardized Measure of Discounted Future Net Cash Flow
Sales of oil and gas, net of productions costs	$ (1,357)	$ (5,302)	$ (2,917)
Net changes in prices and production costs	(25,672)	13,793	14,099
Development costs incurred during the period	637	448	454
Net changes in future development costs	(96)	(289)	(117)
Extensions, discoveries and other additions	69	1,068	504
Divestitures			(125)
Revisions of previous quantity estimates	190	1,475	2,543
Accretion of discount	2,947	1,655	121
Net change in income taxes	5,069	(2,787)	(3,115)
Changes in timing and other	(256)	70	776
Net increase (decrease)	(18,469)	10,131	12,223
Beginning of year	23,564	13,433	1,210
End of year	5,095	23,564	13,433
Future income tax expense included in Standardized Measure	2,200	13,700	7,800
VIE, Martica
Changes in Standardized Measure of Discounted Future Net Cash Flow
Beginning of year	458	501
End of year	$ 170	$ 458	$ 501