Income Taxes (Schedule of Unresolved Income Tax Positions) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning uncertain tax positions	$ 528	$ 540
Increases related to current year income tax positions	62	22
Increases related to prior year income tax positions	5	25
Settlements and resolutions of income tax audits	(78)	(37)
Statute of limitations expirations	(40)	(14)
Foreign currency translation	(5)	(8)
Ending uncertain tax positions	$ 472	$ 528