Derivative Instruments (Hedges of Net Investments in Foreign Operations) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Derivatives, Fair Value [Line Items]
Net Derivatives Gains (Losses) Deferred in AOCI	$ (12)	$ (40)	$ (27)	$ 55
Currency Swap [Member]
Derivatives, Fair Value [Line Items]
Net Derivatives Gains (Losses) Deferred in AOCI	(2)	(6)	(3)	9
Foreign Currency Forwards
Derivatives, Fair Value [Line Items]
Net Derivatives Gains (Losses) Deferred in AOCI	$ (10)	$ (34)	$ (24)	$ 46