Income Taxes (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Undistributed earnings of foreign subsidiaries	$ 700,000,000
Effective tax rate	26.70%	27.30%	25.60%
Net increases in valuation allowances	$ 72,000,000	$ 60,000,000	$ 36,000,000
Decreased income tax expense due to adjustments to valuation allowance	$ (14,000,000)	0	1,000,000
Net operating loss carryforwards (as a percent)	58.00%
Tax Credit Carryforward [Line Items]
Differences related to non-U.S. operations	$ 569,000,000	400,000,000
Unrecognized tax benefits	90,000,000	75,000,000	64,000,000
Accrued interest and penalties, before any applicable federal benefit	40,000,000	$ 31,000,000	$ 15,000,000
Minimum
Tax Credit Carryforward [Line Items]
Reasonably possible decrease in unrecognized tax benefits	0
Maximum
Tax Credit Carryforward [Line Items]
Reasonably possible decrease in unrecognized tax benefits	33,000,000
Federal
Tax Credit Carryforward [Line Items]
Operating loss carryforwards tax benefits	24,000,000
State and Local
Tax Credit Carryforward [Line Items]
Differences related to non-U.S. operations	60,000,000
Operating loss carryforwards tax benefits	25,000,000
Non-U.S.
Tax Credit Carryforward [Line Items]
Operating loss carryforwards tax benefits	$ 94,000,000