Financial Instruments - Derivatives and Hedging (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Assets	$ 61	$ 58
(Liabilities)	(36)	(27)
Currency exchange contracts | Derivatives accounted for as hedges
Derivatives, Fair Value [Line Items]
Assets	1	11
(Liabilities)	(1)	0
Currency exchange contracts | Derivatives not accounted for as hedges
Derivatives, Fair Value [Line Items]
Assets	60	47
(Liabilities)	$ (35)	$ (27)