Income Taxes (Components of income tax expense and reconciliation of effective tax rate) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current
Federal	$ 290	$ 97	$ 47
Foreign	15	(6)	18
State and local	65	45	58
Current income tax expense	370	136	123
Deferred
Federal	(107)	185	243
Foreign	6	14	3
State and local	(20)	5	11
Deferred income tax expense (benefit)	(121)	204	257
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Computed tax at statutory tax rate	239	318	310
State income taxes, net of federal tax benefit	31	43	54
Other permanent items	(3)	(17)	(1)
Change in valuation allowance	(22)	(3)	7
Enactment of the Tax Act	0	0	6
Foreign tax rate differential	4	(1)	4
Total	$ 249	$ 340	$ 380