Consolidated Statement of Shareholders' Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjustment Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2018		147.7
Beginning balance at Dec. 31, 2018	$ 975.2	$ 1.5	$ 2,996.9	$ (1,892.6)	$ (130.6)
Shareholders' Equity (Deficit) [Roll Forward]
Net income	152.9			152.9
Equity-based compensation expense	12.2		12.2
Stock option exercises (in shares)		0.5
Stock option exercises	13.0		13.0
Coworker stock purchase plan	3.0		3.0
Repurchases of common stock (in shares)		(1.9)
Repurchases of common stock	(177.1)	$ 0.0		(177.1)
Dividends paid	(43.4)		0.2	(43.6)
Incentive compensation plan stock withheld for taxes	(11.6)			(11.6)
Foreign currency translation	9.9				9.9
Unrealized (loss) gain from hedge accounting	(8.3)				(8.3)
Realized gain from hedge accounting	(1.5)				1.5
Ending balance (in shares) at Mar. 31, 2019		146.3
Ending balance at Mar. 31, 2019	927.3	$ 1.5	3,025.3	(1,972.0)	(127.5)
Beginning balance (in shares) at Dec. 31, 2019		143.0
Beginning balance at Dec. 31, 2019	960.3	$ 1.4	3,095.3	(2,018.6)	(117.8)	$ 0.5	$ 0.5
Shareholders' Equity (Deficit) [Roll Forward]
Net income	167.9			167.9
Equity-based compensation expense	8.8		8.8
Stock option exercises (in shares)		0.4
Stock option exercises	7.1		7.1
Coworker stock purchase plan	3.5		3.5
Repurchases of common stock (in shares)		(1.1)
Repurchases of common stock	(140.8)	$ 0.0		(140.8)
Dividends paid	(54.2)		0.2	(54.4)
Incentive compensation plan stock withheld for taxes	(21.9)			(21.9)
Foreign currency translation	(42.4)				(42.4)
Unrealized (loss) gain from hedge accounting	(0.2)				(0.2)
Realized gain from hedge accounting	(1.1)				1.1
Ending balance (in shares) at Mar. 31, 2020		142.3
Ending balance at Mar. 31, 2020	$ 889.7	$ 1.4	$ 3,114.9	$ (2,067.3)	$ (159.3)