Income Taxes (Income Tax Components) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current income tax:
Federal	$ 527	$ 531	$ 275
State and local	63	80	45
Foreign	28	36	41
Total current income tax	618	647	361
Deferred income tax:
Federal	(309)	(297)	20
State and local	(16)	(13)	2
Foreign	4	2	3
Total deferred income tax	(321)	(308)	25
Total income tax provision	$ 297	$ 339	386
Final adjustment related to Tax Act			$ 3