LOSS PER SHARE - Computation of Basic and Diluted Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				6 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2022	Sep. 30, 2022	Dec. 31, 2022		Dec. 31, 2021		Dec. 31, 2020
Earnings Per Share [Abstract]
Net loss	$ (58.3)	$ (66.4)	$ (95.5)	$ (77.5)	$ (173.0)	$ (239.4)	$ (297.7)		$ (521.1)		$ (363.0)
Weighted-average common shares outstanding: basic (both Class A and B) (in shares)	14.1	14.1	14.1	14.0	14.0	14.0	14.1	[1]	13.8	[1]	4.2	[1]
Weighted-average common shares outstanding: diluted (both Class A and B) (in shares)	14.1	14.1	14.1	14.0	14.0	14.0	14.1	[1]	13.8	[1]	4.2	[1]
Loss per common share: basic (both Class A and B) (in dollars per share)	$ (4.13)	$ (4.71)	$ (6.77)	$ (5.54)	$ (12.36)	$ (17.10)	$ (21.11)	[1]	$ (37.76)	[1]	$ (86.43)	[1]
Loss per common share: diluted (both Class A and B) (in dollars per share)	$ (4.13)	$ (4.71)	$ (6.77)	$ (5.54)	$ (12.36)	$ (17.10)	$ (21.11)	[1]	$ (37.76)	[1]	$ (86.43)	[1]

[1] Reflects the 1-for-18 reverse stock split that became effective August 12, 2022. Refer to Note 2, “Basis of Presentation and Summary of Significant Accounting Policies.”