Income Taxes (Schedule of Reconciliation of Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Balance at January 1,	$ 56	$ 145	$ 79
Additions based on tax positions related to the current year	10	10	71
Additions for tax positions of previous years	1	15	5
Reductions for tax positions of prior years	(2)	(94)	0
Reductions due to lapse of statute of limitations	(1)	(3)	(7)
Settlements	0	(19)	(4)
Other	(1)	2	1
Balance at December 31,	$ 63	$ 56	$ 145