CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Treasury Stock, at Cost
Beginning balance (in shares) at Dec. 31, 2020		201.8
Beginning balance at Dec. 31, 2020	$ 1,383.7	$ 2.0	$ 2,363.6	$ (18.6)	$ (963.3)	$ 0.0
Beginning balance (in shares) at Dec. 31, 2020						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)		5.0
Exercise of stock options and release of stock awards	45.8	$ 0.1	45.7
Issuance of shares from Employee Stock Purchase Plans (in shares)		0.4
Issuance of shares from Employee Stock Purchase Plans	6.3		6.3
Share-based compensation expense	56.7		56.7
Net loss	(135.4)				(135.4)
Other comprehensive income (loss)	13.9			13.9
Ending balance (in shares) at Sep. 30, 2021		209.9
Ending balance at Sep. 30, 2021	1,371.0	$ 2.1	2,472.3	(4.7)	(1,098.7)	$ 0.0
Ending balance (in shares) at Sep. 30, 2021						0.0
Beginning balance (in shares) at Jun. 30, 2021		209.0
Beginning balance at Jun. 30, 2021	1,382.5	$ 2.1	2,445.3	(1.0)	(1,063.9)	$ 0.0
Beginning balance (in shares) at Jun. 30, 2021						0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and release of stock awards (in shares)		0.9
Exercise of stock options and release of stock awards	7.9		7.9
Share-based compensation expense	19.1		19.1
Net loss	(34.8)				(34.8)
Other comprehensive income (loss)	(3.7)			(3.7)
Ending balance (in shares) at Sep. 30, 2021		209.9
Ending balance at Sep. 30, 2021	$ 1,371.0	$ 2.1	2,472.3	(4.7)	(1,098.7)	$ 0.0
Ending balance (in shares) at Sep. 30, 2021						0.0
Beginning balance (in shares) at Dec. 31, 2021	211.2	211.2
Beginning balance at Dec. 31, 2021	$ 1,327.4	$ 2.1	2,500.0	6.9	(1,181.6)	$ 0.0
Beginning balance (in shares) at Dec. 31, 2021						0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and release of stock awards (in shares)		2.7
Exercise of stock options and release of stock awards	0.7		0.7
Issuance of shares from Employee Stock Purchase Plans (in shares)		0.3
Issuance of shares from Employee Stock Purchase Plans	2.1		2.1
Share-based compensation expense	59.5		59.5
Net loss	(590.8)				(590.8)	$ 0.0
Other comprehensive income (loss)	47.7			47.7
Repurchase of common stock (in shares)						3.1
Repurchase of common stock	$ (31.0)					$ (31.0)
Ending balance (in shares) at Sep. 30, 2022	211.1	214.2
Ending balance at Sep. 30, 2022	$ 815.6	$ 2.1	2,562.3	54.6	(1,772.4)	$ (31.0)
Ending balance (in shares) at Sep. 30, 2022						3.1
Beginning balance (in shares) at Jun. 30, 2022		213.5
Beginning balance at Jun. 30, 2022	1,298.4	$ 2.1	2,542.9	45.1	(1,260.7)	$ (31.0)
Beginning balance (in shares) at Jun. 30, 2022						3.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and release of stock awards (in shares)		0.7
Exercise of stock options and release of stock awards	0.0		0.0
Share-based compensation expense	19.4		19.4
Net loss	(511.7)				(511.7)	$ 0.0
Other comprehensive income (loss)	$ 9.5			9.5
Ending balance (in shares) at Sep. 30, 2022	211.1	214.2
Ending balance at Sep. 30, 2022	$ 815.6	$ 2.1	$ 2,562.3	$ 54.6	$ (1,772.4)	$ (31.0)
Ending balance (in shares) at Sep. 30, 2022						3.1