Segment Information - Segment Reconciliation (Details) $ in Millions	3 Months Ended
	Mar. 31, 2025 USD ($) segment	Mar. 31, 2024 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment	3
Segment Reporting Information [Line Items]
Total Revenue	$ 1,193	$ 1,358
Other Expense, Net	(20)	(22)
Depreciation and Amortization	(62)	(85)
Share-based Compensation	(7)	(13)
Restructuring Charges	(29)	(3)
Other Charges	(13)	(2)
Operating Income	142	233
Operating Segments | DRE
Segment Reporting Information [Line Items]
Total Revenue	350	422
Direct Costs	(226)	(239)
Other Expense, Net	(50)	(53)
Adjusted EBITDA	74	130
Depreciation and Amortization	(19)	(28)
Restructuring Charges	(8)	0
Operating Segments | WCC
Segment Reporting Information [Line Items]
Total Revenue	441	458
Direct Costs	(258)	(276)
Other Expense, Net	(55)	(62)
Adjusted EBITDA	128	120
Depreciation and Amortization	(12)	(23)
Restructuring Charges	(7)	(1)
Operating Segments | PRI
Segment Reporting Information [Line Items]
Total Revenue	334	348
Direct Costs	(230)	(231)
Other Expense, Net	(42)	(44)
Adjusted EBITDA	62	73
Depreciation and Amortization	(18)	(22)
Restructuring Charges	(8)	(1)
All Other
Segment Reporting Information [Line Items]
Total Revenue	68	130
Adjusted EBITDA	4	27
Corporate
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ (15)	$ (14)