Income Taxes (Schedule of Effective Income Tax Rate Reconciliation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Statutory U.S. federal tax expense	$ 227	$ 492	$ 810
Tax credits, excluding expirations	(133)	(73)	(58)
Valuation allowance change, excluding expirations	(91)	54	(78)
Nondeductible expenses	44	31	30
Unrecognized tax benefits	38	(4)	0
Tax law enactment	(18)	0	(1)
State and local income taxes, net of federal income tax benefit	(4)	77	106
Settlement of qualified defined benefit pension plan	0	61	0
Other, net	(2)	(11)	(19)
Total income tax expense from continuing operations	$ 61	$ 627	$ 790