Condensed Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Revenue	$ 2,331.0	$ 1,923.8
Costs and expenses:
Costs of services (exclusive of depreciation and amortization)	1,860.5	1,589.5
Operating, administrative and other	293.4	280.8
Depreciation and amortization	40.6	43.1
Restructuring, impairment and related charges	1.2	17.6
Total costs and expenses	2,195.7	1,931.0
Operating income (loss)	135.3	(7.2)
Interest expense, net of interest income	(43.2)	(42.4)
Earnings from equity method investments	16.9	2.4
Other (expense) income, net	(32.9)	2.0
Earnings (loss) before income taxes	76.1	(45.2)
Provision for (benefit from) income taxes	30.6	(28.0)
Net income (loss)	$ 45.5	$ (17.2)
Basic earnings (loss) per share:
Earnings (loss) per share attributable to common shareholders, basic (in dollars per share)	$ 0.20	$ (0.08)
Weighted average shares outstanding for basic earnings (loss) per share	224.7	222.3
Diluted earnings (loss) per share:
Earnings (loss) per share attributable to common shareholders, diluted (in dollars per share)	$ 0.20	$ (0.08)
Weighted average shares outstanding for diluted earnings (loss) per share	229.1	222.3