CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' DEFICIT (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit	Treasury Stock, at Cost
Beginning balance (in shares) at Dec. 31, 2023		220.5
Beginning balance at Dec. 31, 2023	$ (154.5)	$ 2.2	$ 2,638.2	$ 60.3	$ (2,824.2)	$ (31.0)
Beginning balance (in shares) at Dec. 31, 2023						3.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and release of stock awards, net of shares withheld (in shares)		9.9
Exercise of stock options and release of stock awards, net of shares withheld	(4.3)	$ 0.1	(4.4)
Issuance of shares from Employee Stock Purchase Plans (in shares)		0.3
Issuance of shares from Employee Stock Purchase Plan	0.4		0.4
Share-based compensation expense for equity classified awards	37.8		37.8
Net loss	(802.2)				(802.2)
Other comprehensive loss	(26.9)			(26.9)
Ending balance (in shares) at Sep. 30, 2024		230.7
Ending balance at Sep. 30, 2024	(949.7)	$ 2.3	2,672.0	33.4	(3,626.4)	$ (31.0)
Ending balance (in shares) at Sep. 30, 2024						3.1
Beginning balance (in shares) at Jun. 30, 2024		228.7
Beginning balance at Jun. 30, 2024	(756.2)	$ 2.3	2,661.1	51.2	(3,439.8)	$ (31.0)
Beginning balance (in shares) at Jun. 30, 2024						3.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and release of stock awards, net of shares withheld (in shares)		2.0
Exercise of stock options and release of stock awards, net of shares withheld	(0.9)		(0.9)
Share-based compensation expense for equity classified awards	11.8		11.8
Net loss	(186.6)				(186.6)
Other comprehensive loss	(17.8)			(17.8)
Ending balance (in shares) at Sep. 30, 2024		230.7
Ending balance at Sep. 30, 2024	$ (949.7)	$ 2.3	2,672.0	33.4	(3,626.4)	$ (31.0)
Ending balance (in shares) at Sep. 30, 2024						3.1
Beginning balance (in shares) at Dec. 31, 2024	229.1	232.2
Beginning balance at Dec. 31, 2024	$ (1,004.2)	$ 2.3	2,682.8	24.1	(3,682.4)	$ (31.0)
Beginning balance (in shares) at Dec. 31, 2024	3.1					3.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and release of stock awards, net of shares withheld (in shares)		14.2
Exercise of stock options and release of stock awards, net of shares withheld	$ (2.0)	$ 0.2	(2.2)
Issuance of shares from Employee Stock Purchase Plans (in shares)		0.3
Issuance of shares from Employee Stock Purchase Plan	0.3		0.3
Share-based compensation expense for equity classified awards	24.3		24.3
Net loss	(193.1)				(193.1)
Other comprehensive loss	$ (12.5)			(12.5)
Ending balance (in shares) at Sep. 30, 2025	243.6	246.7
Ending balance at Sep. 30, 2025	$ (1,187.2)	$ 2.5	2,705.2	11.6	(3,875.5)	$ (31.0)
Ending balance (in shares) at Sep. 30, 2025	3.1					3.1
Beginning balance (in shares) at Jun. 30, 2025		242.1
Beginning balance at Jun. 30, 2025	$ (1,119.0)	$ 2.4	2,696.7	21.3	(3,808.4)	$ (31.0)
Beginning balance (in shares) at Jun. 30, 2025						3.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and release of stock awards, net of shares withheld (in shares)		4.6
Exercise of stock options and release of stock awards, net of shares withheld	(1.2)	$ 0.1	(1.3)
Share-based compensation expense for equity classified awards	9.8		9.8
Net loss	(67.1)				(67.1)
Other comprehensive loss	$ (9.7)			(9.7)
Ending balance (in shares) at Sep. 30, 2025	243.6	246.7
Ending balance at Sep. 30, 2025	$ (1,187.2)	$ 2.5	$ 2,705.2	$ 11.6	$ (3,875.5)	$ (31.0)
Ending balance (in shares) at Sep. 30, 2025	3.1					3.1