FLOOR PLAN NOTES PAYABLE - Schedule of Floor Plan Notes Payable (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Debt Disclosure [Abstract]
Floor plan notes payable—trade	$ 31.7	$ 39.3
Floor plan notes payable offset account	(4.0)	(2.0)
Floor plan notes payable—trade, net	27.7	37.3
Floor plan notes payable—non-trade	317.0	314.7
Floor plan notes payable—used non-trade	0.0	294.0
Floor plan notes payable offset account	(300.3)	(81.5)
Floor plan notes payable—non-trade, net	16.7	527.2
Floor plan notes payable—non-trade, liabilities associated with assets held for sale	$ 1.1	$ 9.1