Income Taxes (Components of income tax expense and reconciliation of effective tax rate) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current
Federal	$ 97	$ 47	$ 190
Foreign	(6)	18	15
State and local	45	58	30
Current income tax expense	136	123	235
Deferred
Federal	185	243	(580)
Foreign	14	3	(2)
State and local	5	11	49
Deferred income tax expense (benefit)	204	257	(533)
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Computed tax at statutory tax rate	318	310	367
State income taxes, net of federal tax benefit	43	54	34
Other permanent items	(20)	6	(3)
Enactment of the Tax Act	0	6	(689)
Foreign tax rate differential	(1)	4	(7)
Total	$ 340	$ 380	$ (298)