CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Treasury Stock, at Cost
Beginning balance (in shares) at Dec. 31, 2020		201.8				0.0
Beginning balance at Dec. 31, 2020	$ 1,383.7	$ 2.0	$ 2,363.6	$ (18.6)	$ (963.3)	$ 0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)		2.7
Exercise of stock options and release of stock awards (in shares)		2.5
Exercise of stock options and release of stock awards	21.9	$ 0.1	21.8
Share-based compensation expense	17.2		17.2
Net loss	(64.0)				(64.0)
Other comprehensive income	16.4			16.4
Ending balance (in shares) at Mar. 31, 2021		207.0				0.0
Ending balance at Mar. 31, 2021	1,375.2	$ 2.1	2,402.6	(2.2)	(1,027.3)	$ 0.0
Beginning balance (in shares) at Dec. 31, 2021		211.2				0.0
Beginning balance at Dec. 31, 2021	1,327.4	$ 2.1	2,500.0	6.9	(1,181.6)	$ 0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and release of stock awards (in shares)		1.6
Exercise of stock options and release of stock awards	0.5		0.5
Share-based compensation expense	17.0		17.0
Net loss	(38.5)				(38.5)
Other comprehensive income	42.0			42.0
Repurchase of common stock (in shares)						0.4
Repurchase of common stock	(4.1)					$ (4.1)
Ending balance (in shares) at Mar. 31, 2022		212.8				0.4
Ending balance at Mar. 31, 2022	$ 1,344.3	$ 2.1	$ 2,517.5	$ 48.9	$ (1,220.1)	$ (4.1)