Income Taxes (Reconciliation of Beginning and Ending Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Reconciliation of Unrecognized Tax Benefits
Balance at beginning of year	$ 69	$ 53	$ 74
Additions based on tax positions related to the current year	1,548	1	0
Additions for tax positions of prior years	0	16	40
Reductions for tax positions due to lapse of statutes of limitations	0	0	(5)
Reductions for tax positions of prior years	(6)	0	(23)
Tax settlements	(3)	(1)	(33)
Balance at end of year	$ 1,608	$ 69	$ 53