Consolidated Condensed Statements of Stockholders’ Equity - USD ($) $ in Millions	Total	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Common Class A Common Stock	Common Class B Common Stock
Beginning balance (in shares) at Dec. 31, 2021					162,789,591	74,937,945
Beginning balance at Dec. 31, 2021	$ 698.9	$ 1,072.5	$ (373.6)	$ 0.0	$ 0.0	$ 0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of Class B common stock to Class A common stock (in shares)					1,757,980	(1,757,980)
Issuance of restricted stock units and restricted stock expense (in shares)					300,014
Issuance of restricted stock units and restricted stock expense	16.0	16.0
Exercise of stock options (in shares)					353,640	399,621
Exercise of stock options	0.1	0.1
Issuance of warrants and warrant expense	1.2	1.2
Stock-based compensation	6.7	6.7
Net loss	(59.2)		(59.2)
Ending balance (in shares) at Mar. 31, 2022					165,201,225	73,579,586
Ending balance at Mar. 31, 2022	663.7	1,096.5	(432.8)	0.0	$ 0.0	$ 0.0
Beginning balance (in shares) at Dec. 31, 2021					162,789,591	74,937,945
Beginning balance at Dec. 31, 2021	698.9	1,072.5	(373.6)	0.0	$ 0.0	$ 0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(130.9)
Other comprehensive income	0.0
Ending balance (in shares) at Jun. 30, 2022					170,725,779	65,729,445
Ending balance at Jun. 30, 2022	618.2	1,122.7	(504.5)	0.0	$ 0.0	$ 0.0
Beginning balance (in shares) at Mar. 31, 2022					165,201,225	73,579,586
Beginning balance at Mar. 31, 2022	663.7	1,096.5	(432.8)	0.0	$ 0.0	$ 0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of Class B common stock to Class A common stock (in shares)					4,190,561	(4,190,561)
Issuance of restricted stock units and restricted stock expense (in shares)					992,006
Issuance of restricted stock units and restricted stock expense	17.9	17.9
Exercise of stock options (in shares)					341,987	1,342,726
Exercise of stock options	0.2	0.2	0.0	0.0
Issuance of warrants and warrant expense	1.6	1.6
Cancellation of Class B common stock (Note 9) (in shares)						(5,002,306)
Stock-based compensation	6.5	6.5
Net loss	(71.7)		(71.7)
Other comprehensive income	0.0
Ending balance (in shares) at Jun. 30, 2022					170,725,779	65,729,445
Ending balance at Jun. 30, 2022	618.2	1,122.7	(504.5)	0.0	$ 0.0	$ 0.0
Beginning balance (in shares) at Dec. 31, 2022					177,900,738	63,738,197
Beginning balance at Dec. 31, 2022	493.3	1,185.0	(690.9)	(0.8)	$ 0.0	$ 0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of Class B common stock to Class A common stock (in shares)					2,250,000	(2,250,000)
Issuance of restricted stock units and restricted stock expense (in shares)					2,191,898
Issuance of restricted stock units and restricted stock expense	18.8	18.8
Exercise of stock options (in shares)					316,116	233,190
Exercise of stock options	0.1	0.1
Issuance of warrants and warrant expense	6.3	6.3
Common stock withheld related to net share settlement of equity awards (in shares)					(786,342)
Common stock withheld related to net share settlement of equity awards	(2.3)	(2.3)
Stock-based compensation	6.3	6.3
Net loss	(113.1)		(113.1)
Other comprehensive income	0.7			0.7
Ending balance (in shares) at Mar. 31, 2023					181,872,410	61,721,387
Ending balance at Mar. 31, 2023	410.1	1,214.2	(804.0)	(0.1)	$ 0.0	$ 0.0
Beginning balance (in shares) at Dec. 31, 2022					177,900,738	63,738,197
Beginning balance at Dec. 31, 2022	$ 493.3	1,185.0	(690.9)	(0.8)	$ 0.0	$ 0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	1,088,501
Net loss	$ (297.2)
Other comprehensive income	0.8
Ending balance (in shares) at Jun. 30, 2023					204,468,116	47,845,269
Ending balance at Jun. 30, 2023	276.3	1,264.4	(988.1)	0.0	$ 0.0	$ 0.0
Beginning balance (in shares) at Mar. 31, 2023					181,872,410	61,721,387
Beginning balance at Mar. 31, 2023	410.1	1,214.2	(804.0)	(0.1)	$ 0.0	$ 0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of Class B common stock to Class A common stock (in shares)					14,109,310	(14,109,310)
Issuance of restricted stock units and restricted stock expense (in shares)					1,834,274
Issuance of restricted stock units and restricted stock expense	16.2	16.2
Exercise of stock options (in shares)					306,003	233,192
Exercise of stock options	0.1	0.1
Issuance of warrants and warrant expense	4.5	4.5
Common stock withheld related to net share settlement of equity awards (in shares)					(592,025)
Common stock withheld related to net share settlement of equity awards	(1.2)	(1.2)
Common stock issued under employee stock purchase plan (in shares)					601,105
Common stock issued under employee stock purchase plan	1.3	1.3
Common stock issued under stock purchase agreement (in shares)					6,337,039
Common stock issued under stock purchase agreement	21.4	21.4
Stock-based compensation	7.9	7.9
Net loss	(184.1)		(184.1)
Other comprehensive income	0.1			0.1
Ending balance (in shares) at Jun. 30, 2023					204,468,116	47,845,269
Ending balance at Jun. 30, 2023	$ 276.3	$ 1,264.4	$ (988.1)	$ 0.0	$ 0.0	$ 0.0