Income Taxes - Schedule of Provision For Income Taxes (Details) - USD ($) $ in Millions	6 Months Ended		12 Months Ended
	Dec. 31, 2021	Jun. 30, 2021	Dec. 31, 2023	Dec. 31, 2022
Current
Federal	$ 17		$ (10)	$ (10)
State	3		11	5
Foreign	6		4	10
Total current tax expense (benefit)	26		5	5
Deferred tax expense (benefit):
Federal			(3)	18
State			(8)	6
Foreign	(1)		2	2
Total deferred tax (benefit) expense	(1)		(9)	26
Total income tax expense (benefit)	$ 25		$ (4)	$ 31
Alight Holdings
Current
Federal		$ 1
Foreign		(5)
Total current tax expense (benefit)		(4)
Deferred tax expense (benefit):
Foreign		(1)
Total deferred tax (benefit) expense		(1)
Total income tax expense (benefit)		$ (5)