Derivative Instruments (Hedges of Net Investments in Foreign Operations) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivatives, Fair Value [Line Items]
Net Derivatives Gains (Losses) Deferred in AOCI	$ (40)	$ (8)	$ 55	$ (34)
Currency Swap [Member]
Derivatives, Fair Value [Line Items]
Net Derivatives Gains (Losses) Deferred in AOCI	(6)	(2)	9	(10)
Foreign Exchange Forward [Member]
Derivatives, Fair Value [Line Items]
Net Derivatives Gains (Losses) Deferred in AOCI	$ (34)	$ (6)	$ 46	$ (24)