Derivative Instruments - Pre-tax Gains (Losses) on Cash Flow Hedges (Details) - Designated as hedging instrument - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Foreign exchange forward contracts | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Accumulated Other Comprehensive Loss (effective portion)	$ (2)	$ 2	$ 0
Foreign exchange forward contracts | Revenue, Selling and general expenses | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Income (effective portion)	5	(4)	9
Cross currency swap | Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Accumulated Other Comprehensive Loss (effective portion)	(10)	0	0
Cross currency swap | Revenue, Selling and general expenses | Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Income (effective portion)	$ 0	$ 0	$ 0