CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Income Statement [Abstract]
Revenues	$ 701.3	$ 674.9	$ 2,062.9	$ 1,999.4
Costs and expenses:
Direct costs, exclusive of depreciation and amortization	578.6	526.6	1,690.2	1,606.1
Selling, general and administrative expenses, exclusive of depreciation and amortization	106.8	136.3	353.4	412.6
Depreciation and amortization	19.6	21.2	58.7	64.5
Goodwill and other asset impairments	0.0	0.0	797.9	0.0
Restructuring and other charges	4.9	8.8	21.7	22.5
Total costs and expenses	709.9	692.9	2,921.9	2,105.7
Operating loss	(8.6)	(18.0)	(859.0)	(106.3)
Other income (expense):
Interest expense	(22.6)	(22.4)	(68.2)	(101.9)
Foreign exchange loss	(2.6)	(0.2)	(28.1)	(7.0)
Other, net	5.1	4.8	7.9	15.1
Loss from continuing operations before income taxes	(28.7)	(35.8)	(947.4)	(200.1)
Income tax (benefit) expense	(12.8)	(17.3)	6.3	(2.5)
Loss from continuing operations	(15.9)	(18.5)	(953.7)	(197.6)
Loss from discontinued operations, net of tax	0.0	(9.4)	0.0	(69.7)
Net loss	$ (15.9)	$ (27.9)	$ (953.7)	$ (267.3)
Earnings (loss) per common share
Basic earnings (loss) per share from continuing operations (in dollars per share)	$ (0.17)	$ (0.21)	$ (10.53)	$ (2.21)
Basic earnings (loss) per share form discontinued operations (in dollars per share)	0	(0.10)	0	(0.78)
Basic earnings (loss) per share (in dollars per share)	(0.17)	(0.31)	(10.53)	(2.99)
Diluted earnings (loss) per share continuing from operations (in dollars per share)	(0.17)	(0.21)	(10.53)	(2.21)
Diluted earnings (loss) per share from discontinued operations (in dollars per share)	0	(0.10)	0	(0.78)
Diluted earnings (loss) per share (in dollars per share)	$ (0.17)	$ (0.31)	$ (10.53)	$ (2.99)