Objectives and Strategies for Using Derivatives (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Foreign Exchange Contract \| Not Designated as Hedging Instrument
Aggregate notional value	$ 1,900
Gains (Losses) on undesignated foreign exchange hedging instruments	(17)	$ 52	$ (37)
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 2
Derivative Assets	34	30
Derivative Liability	44	$ 18
Net Investment Hedging \| Foreign Exchange Contract
Aggregate notional value	1,500
Fair Value Hedging \| Interest Rate Contract
Aggregate notional value	300
Long-term Debt, Fair Value	308
Cash Flow Hedging \| Foreign Exchange Contract
Aggregate notional value	$ 652

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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