Accumulated Other Comprehensive Income - Summary of Changes in Balances for Each Component of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	$ 1,643	$ 1,615	$ 1,370	$ (818)	$ 1,615	$ (818)
Other comprehensive income (loss)	(1)	3	1	(2)
Ending balance	1,676	1,643	1,484	1,370	1,676	1,484
Currency Translation Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Balance as of beginning of period	(6)	(6)	(8)	(6)	(6)	(6)
Currency translation adjustments			1			(1)
Other comprehensive income (loss)			1			(1)
Balance as of end of period	(6)	(6)	(7)	(8)	(6)	(7)
Employee Benefit Plans
Accumulated Other Comprehensive Income Loss [Line Items]
Balance as of beginning of period	8	8	11	11	8	11
Balance as of end of period	8	8	11	11	8	11
Interest Rate Derivatives
Accumulated Other Comprehensive Income Loss [Line Items]
Balance as of beginning of period	2	(1)			(1)
(Loss) income arising during period	(1)				2
Other comprehensive income (loss)	(1)				2
Balance as of end of period	1	2			1
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	4	1	3	5	1	5
Other comprehensive income (loss)	(1)	3	1	(2)	2	(1)
Ending balance	$ 3	$ 4	$ 4	$ 3	$ 3	$ 4