Derivative Instruments - Notional Amounts of Derivatives Outstanding (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative, notional amount	$ 5,917	$ 4,622
Foreign Exchange Contract | Designated as Hedging Instrument | Cash Flow Hedging
Derivatives, Fair Value [Line Items]
Derivative, notional amount	2,022	1,983
Foreign Exchange Contract | Designated as Hedging Instrument | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Derivative, notional amount	165	200
Foreign Exchange Contract | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, notional amount	2,630	2,439
Interest Rate Contract | Designated as Hedging Instrument | Cash Flow Hedging
Derivatives, Fair Value [Line Items]
Derivative, notional amount	$ 1,100	$ 0