Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Retained Earnings	Treasury stock common member
Balance at beginning of period at Dec. 31, 2020		$ 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
Common stock repurchases						0.0
Stock-based compensation expense			7.1
Other comprehensive income (loss)				(4.9)
Net income (loss)	$ 11.0				11.0
Balance at end of period at Dec. 31, 2021	662.4	0.4	602.4	(102.4)	227.9	(65.9)
Increase (Decrease) in Stockholders' Equity
Stock options exercised and issuance of other stock awards			(4.2)			3.2
Common stock repurchases						(3.0)
Stock-based compensation expense			8.5
Other comprehensive income (loss)				(5.5)
Net income (loss)	(123.6)				(123.6)
Balance at end of period at Dec. 31, 2022	537.8	0.4	606.7	(107.9)	104.3	(65.7)
Increase (Decrease) in Stockholders' Equity
Stock options exercised and issuance of other stock awards			(5.1)			3.9
Common stock repurchases						(5.5)
Stock-based compensation expense			11.5
Other comprehensive income (loss)				21.5
Net income (loss)	39.2				39.2
Balance at end of period at Dec. 31, 2023	$ 603.3	$ 0.4	$ 613.1	$ (86.4)	$ 143.5	$ (67.3)