Derivative Instruments - Notional Amount of Derivatives Outstanding (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 6,566	$ 4,459
Foreign Exchange Contract | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,027	2,276
Cash Flow Hedging | Foreign Exchange Contract | Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,305	1,983
Cash Flow Hedging | Interest Rate Contract | Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,100	0
Net Investment Hedging | Foreign Exchange Contract | Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 134	$ 200