Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ (24.5)	$ (23.0)
Other comprehensive income (loss), net of tax:
Change in foreign currency translation adjustment	(31.2)	(15.5)
Net change in unrealized gains (losses) on available-for-sale marketable debt securities		(0.1)
Other comprehensive income (loss), net of tax	(31.2)	(15.6)
Comprehensive income (loss)	$ (55.7)	$ (38.6)