Consolidated Statements of Stockholders' Equity - USD ($) $ 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 income (loss)	Treasury stock
Beginning balance (shares) at Dec. 31, 2018			42,331,900
Beginning balance at Dec. 31, 2018	$ 338.7		$ 0.4	$ 98.3	$ 313.5		$ (17.7)	$ (55.8)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	183.7				183.7
Other comprehensive income (loss)	12.7						12.7
Common stock issued (shares)			283,300
Exercise of stock options, net (shares)			60,000.0
Exercise of stock options, net	1.7			1.7
Tax payments related to vested restricted stock units	(14.3)							(14.3)
Share repurchase program	(6.4)							(6.4)
Share-based compensation plans	14.7			12.8				1.9
Ending balance (shares) at Dec. 31, 2019			42,675,200
Ending balance at Dec. 31, 2019	530.8	$ (0.6)	$ 0.4	112.8	497.2	$ (0.6)	(5.0)	(74.6)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	181.4				181.4
Other comprehensive income (loss)	9.7						9.7
Common stock issued (shares)			174,600
Exercise of stock options, net (shares)			63,000.0
Exercise of stock options, net	1.9			1.9
Tax payments related to vested restricted stock units	(3.2)							(3.2)
Share repurchase program	(88.0)							(88.0)
Share-based compensation plans	$ 10.1			6.6				3.5
Ending balance (shares) at Dec. 31, 2020	40,509,997		42,912,800
Ending balance at Dec. 31, 2020	$ 642.1		$ 0.4	121.3	678.0		4.7	(162.3)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	118.1				118.1
Other comprehensive income (loss)	$ 8.4						8.4
Common stock issued (shares)			121,400
Exercise of stock options, net (shares)	59,000		67,800
Exercise of stock options, net	$ 3.0			3.0
Tax payments related to vested restricted stock units	(2.4)							(2.4)
Share repurchase program	(109.4)							(109.4)
Share-based compensation plans	$ 14.0			12.0				2.0
Ending balance (shares) at Dec. 31, 2021	39,269,399		43,102,000
Ending balance at Dec. 31, 2021	$ 673.8		$ 0.4	$ 136.3	$ 796.1		$ 13.1	$ (272.1)