Other Financial Data - Additional Information (Details) - USD ($)	3 Months Ended			6 Months Ended	9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Sep. 30, 2021	Jun. 30, 2021	Sep. 30, 2022	Dec. 31, 2021
Other Financial Data [Line Items]
Contract with customer, liability, revenue recognized			$ 22,000,000		$ 108,000,000
Unrecognized tax benefits recognition of benefits					29,000,000
Deferred consideration payments, Paid		$ 81,000,000			81,000,000
Alight Holdings
Other Financial Data [Line Items]
Contract with customer, liability, revenue recognized				$ 101,000,000
Deferred consideration payments, Paid				1,000,000
Interest Rate Swaps
Other Financial Data [Line Items]
Derivative asset, current	$ 60,000,000				60,000,000	$ 1,000,000
Derivative asset, noncurrent	82,000,000				82,000,000	16,000,000
Derivative liability, current	0				0	8,000,000
Derivative liability, noncurrent	0				0	1,000,000
Other Current Liabilities
Other Financial Data [Line Items]
Tax receivable agreement liability	6,000,000				6,000,000
Deferred compensation liability						$ 83,000,000
Cost of Services, Exclusive of Depreciation and Amortization
Other Financial Data [Line Items]
Amortization expense	$ 12,000,000				$ 37,000,000
Cost of Services, Exclusive of Depreciation and Amortization | Alight Holdings
Other Financial Data [Line Items]
Amortization expense			$ 17,000,000	$ 33,000,000