Financial Instruments - Derivatives and Hedging (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Assets	$ 109	$ 58
(Liabilities)	(63)	(27)
Currency exchange contracts | Derivatives accounted for as hedges
Derivatives, Fair Value [Line Items]
Assets	4	11
(Liabilities)	0	0
Currency exchange contracts | Derivatives not accounted for as hedges
Derivatives, Fair Value [Line Items]
Assets	105	47
(Liabilities)	$ (63)	$ (27)