Accumulated other comprehensive income (loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of period	$ 666
Balance at the end of period	761	$ 666
Accumulated other comprehensive income (loss)
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of period	82	113	$ 123
Other comprehensive (loss) income	(24)	(33)	(4)
Tax expense	1	2	(6)
Balance at the end of period	59	82	113
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of period	111	130	123
Other comprehensive (loss) income	14	(19)	7
Tax expense	1
Balance at the end of period	126	111	130
Net (Loss) Income Hedge Investments in Foreign Operations
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of period	51
Balance at the end of period		51
Unrecognized (Loss) Gain on Derivative Instruments
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of period		7	10
Other comprehensive (loss) income	(12)	(10)	(3)
Tax expense		3
Balance at the end of period	(12)		7
Pension Adjustments
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of period	(29)	(24)	(10)
Other comprehensive (loss) income	(26)	(4)	(8)
Tax expense		(1)	(6)
Balance at the end of period	$ (55)	$ (29)	$ (24)