Derivatives and Hedging - Notional and fair values of derivative instruments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Other Current Assets
Derivative [Line Items]
Derivative assets	$ 11	$ 7
Other Noncurrent Assets
Derivative [Line Items]
Derivative assets	23	11
Other Current Liabilities
Derivative [Line Items]
Derivative liabilities	1	1
Accounted for as hedges | Gross foreign exchange contracts
Derivative [Line Items]
Derivative, Notional Amount	633	579
Derivative assets	33	16
Derivative liabilities	0	1
Not accounted for as hedges
Derivative [Line Items]
Derivative, Notional Amount	1,000	876
Derivative assets	34	18
Derivative liabilities	1	1
Not accounted for as hedges | Gross foreign exchange contracts
Derivative [Line Items]
Derivative, Notional Amount	367	297
Derivative assets	1	2
Derivative liabilities	$ 1	$ 0
Derivative term of contract	90 days