Income Taxes (Income Tax Components) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Payable related to accrued interest and penalties	$ 8	$ 10
Current income tax:
Federal	531	275	$ 468
State and local	80	45	58
Foreign	36	41	52
Total current income tax	647	361	578
Deferred income tax:
Federal	(297)	20	169
State and local	(13)	2	(5)
Foreign	2	3	(8)
Total deferred income tax	(308)	25	156
Total income tax provision	$ 339	386	734
Expense related to the enactment of the Tax Act			286
Remeasurement of deferred tax assets and liabilities to Tax Act's statutory 21%			221
Expense for the foreign provisions of the Tax Act			57
Remeasurement of tax contingencies related to the Tax Act			$ 8
Final adjustment related to Tax Act		$ 3