Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Retained Earnings	Retained Earnings Cumulative Effect Period Of Adoption Adjustment	Treasury Stock
Balance at beginning of year at Dec. 31, 2018		$ 0.4	$ 584.8	$ (116.6)	$ 189.6		$ (56.9)
Increase (Decrease) in Stockholders' Equity
Stock options exercised and issuance of other stock awards			(2.1)				2.4
Common stock repurchases							(7.4)
Stock-based compensation			9.5
Other comprehensive income (loss)				(4.4)
Net income (loss)	$ 46.6				46.6
Balance at end of year at Dec. 31, 2019	645.9	0.4	592.2	(121.0)	236.2	$ (0.2)	(61.9)
Increase (Decrease) in Stockholders' Equity
Stock options exercised and issuance of other stock awards			(3.1)				2.5
Common stock repurchases							(12.0)
Stock-based compensation			6.0
Other comprehensive income (loss)				23.5
Net income (loss)	(19.1)				(19.1)
Balance at end of year at Dec. 31, 2020	643.5	0.4	595.1	(97.5)	216.9		(71.4)
Increase (Decrease) in Stockholders' Equity
Stock options exercised and issuance of other stock awards			0.2				5.5
Stock-based compensation			7.1
Other comprehensive income (loss)				(4.9)
Net income (loss)	11.0				11.0
Balance at end of year at Dec. 31, 2021	$ 662.4	$ 0.4	$ 602.4	$ (102.4)	$ 227.9		$ (65.9)