Consolidated Condensed Statements of Comprehensive Loss - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Net loss	$ (184.1)	$ (71.7)	$ (297.2)	$ (130.9)
Other comprehensive income:
Unrealized gain on available-for-sale securities, net of tax	0.1	0.0	0.8	0.0
Comprehensive loss	$ (184.0)	$ (71.7)	$ (296.4)	$ (130.9)