Supplemental Oil and Gas Disclosures (Unaudited) (Schedule of Analysis of Changes in Standardized Measure) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Standardized measure, beginning of year	$ 1,847	$ 3,700	$ 5,999
Sales and transfers of natural gas and oil produced, net of production costs	(3,332)	(478)	(923)
Net changes in prices and production costs	10,417	(2,720)	(3,510)
Extensions, discoveries, and other additions, net of future production and development costs	3,183	81	234
Increase Due to Purchases of Minerals in Place	6,499	443	0
Sales of reserves in place	(1)	0	(2)
Revisions of previous quantity estimates	596	(987)	152
Net change in income taxes	(3,689)	35	491
Changes in estimated future development costs	137	1,241	621
Previously estimated development costs incurred during the year	419	624	704
Changes in production rates (timing) and other	2,470	(466)	(718)
Accretion of discount	185	374	652
Standardized measure, end of year	$ 18,731	$ 1,847	$ 3,700