Condensed Consolidated Statements of Comprehensive Loss (unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (26.0)	$ (54.7)
Change in unrealized loss on available-for-sale debt securities, net of tax	0.1	1.2
Change in foreign currency translation adjustment, net of tax	(1.3)	0.3
Reclassification of cumulative translation adjustment to income upon liquidation of an investment in a foreign entity, net of tax	0.7	0.0
Comprehensive loss	$ (26.5)	$ (53.2)