Fair Value Measurement - Summary of Changes in Deferred Contingent Consideration Liabilities (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Business Acquisition, Contingent Consideration [Line Items]
Beginning balance	$ 32		$ 33
Measurement period adjustments			(2)
Accretion of contingent consideration			1
Remeasurement of acquisition-related contingent consideration	(7)		(7)
Ending Balance	$ 25		$ 25
Alight Holdings
Business Acquisition, Contingent Consideration [Line Items]
Beginning balance		$ 28		$ 26
Measurement period adjustments				2
Accretion of contingent consideration		1		1
Ending Balance		$ 29		$ 29