CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) shares in Millions, $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-In Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Loss	Noncontrolling Interests
Beginning Balance at Dec. 31, 2019	$ 2,334.7	$ (2.5)	$ 0.9	$ 1,205.7	$ 1,442.4	$ (2.5)	$ (318.1)	$ 3.8
Beginning Balance (in shares) at Dec. 31, 2019			91.2
Net (loss) income	(104.9)				(105.8)			0.9
Currency translation adjustments	1.5						1.3	0.2
Cumulative currency translation loss realized through disposition of operations	87.2						87.2
Issuance of common stock for incentive stock programs, net of (payments of) taxes from withheld shares	2.2			2.2
Issuance of common stock for incentive stock programs, net of (payments of) taxes from withheld shares (in shares)			0.3
Stock-based compensation expense	20.3			20.3
Ending Balance at Sep. 30, 2020	2,338.5		$ 0.9	1,228.2	1,334.1		(229.6)	4.9
Ending Balance (in shares) at Sep. 30, 2020			91.5
Beginning Balance at Jun. 30, 2020	2,296.1		$ 0.9	1,222.4	1,415.3		(347.0)	4.5
Beginning Balance (in shares) at Jun. 30, 2020			91.5
Net (loss) income	(80.9)				(81.2)			0.3
Currency translation adjustments	30.3						30.2	0.1
Cumulative currency translation loss realized through disposition of operations	87.2						87.2
Issuance of common stock for incentive stock programs, net of (payments of) taxes from withheld shares	(1.6)			(1.6)
Stock-based compensation expense	7.4			7.4
Ending Balance at Sep. 30, 2020	2,338.5		$ 0.9	1,228.2	1,334.1		(229.6)	4.9
Ending Balance (in shares) at Sep. 30, 2020			91.5
Beginning Balance at Dec. 31, 2020	2,434.4		$ 0.9	1,234.0	1,382.6		(187.4)	4.3
Beginning Balance (in shares) at Dec. 31, 2020			91.6
Net (loss) income	(10.4)				(10.6)			0.2
Currency translation adjustments	(24.6)						(24.4)	(0.2)
Cumulative currency translation loss realized through disposition of operations	3.8						3.8
Issuance of common stock for incentive stock programs, net of (payments of) taxes from withheld shares	0.8			0.8
Issuance of common stock for incentive stock programs, net of (payments of) taxes from withheld shares (in shares)			0.2
Stock-based compensation expense	18.8			18.8
Changes to noncontrolling interest	(0.6)							(0.6)
Ending Balance at Sep. 30, 2021	2,422.2		$ 0.9	1,253.6	1,372.0		(208.0)	3.7
Ending Balance (in shares) at Sep. 30, 2021			91.8
Beginning Balance at Jun. 30, 2021	2,493.5		$ 0.9	1,244.6	1,438.0		(193.7)	3.7
Beginning Balance (in shares) at Jun. 30, 2021			91.8
Net (loss) income	(65.9)				(66.0)			0.1
Currency translation adjustments	(18.2)						(18.1)	(0.1)
Cumulative currency translation loss realized through disposition of operations	3.8						3.8
Issuance of common stock for incentive stock programs, net of (payments of) taxes from withheld shares	2.3			2.3
Stock-based compensation expense	6.7			6.7
Ending Balance at Sep. 30, 2021	$ 2,422.2		$ 0.9	$ 1,253.6	$ 1,372.0		$ (208.0)	$ 3.7
Ending Balance (in shares) at Sep. 30, 2021			91.8