Discontinued Operations and Assets Held for Sale - Summary of Income (loss) from Discontinued Operations on Condensed Consolidated Statements of Comprehensive Income (loss) (Details) - Professional Service Segment And Payroll And HCM Outsourcisg Business - Discontinued Operations, Held-for-Sale - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	$ 249	$ 245	$ 506	$ 490
Cost of services, exclusive of depreciation and amortization	167	172	354	345
Depreciation and amortization	0	3	3	5
Gross Profit	82	70	149	140
Operating Expenses
Selling, general and administrative	52	44	89	78
Depreciation and intangible amortization	0	11	8	20
Total Operating Expenses	52	55	97	98
Income (loss) from Discontinued Operations	30	15	52	42
Interest expense	0	0	0	0
Other (income) expense, net	0	4	2	6
Income (Loss) from Discontinued Operations Before Income Taxes	30	11	50	36
Income tax expense (benefit)	3	11	18	26
Net Income (Loss) from Discontinued Operations, Net of Tax	$ 27	$ 0	$ 32	$ 10