FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Impact of Interest Rate Derivative Instruments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Derivative
Amount of Unrealized Income (Loss), Net of Tax, Recognized in Other Comprehensive Income (Loss)	$ 15.1	$ 31.9	$ 27.3	$ 84.8
Amount Reclassified from Other Comprehensive Income (Loss) into Statements of Operations	6.7	1.4	18.6	(1.6)
Floorplan interest expense
Derivative
Amount Reclassified from Other Comprehensive Income (Loss) into Statements of Operations	4.1	0.7	11.2	(1.4)
Other interest expense, net
Derivative
Amount Reclassified from Other Comprehensive Income (Loss) into Statements of Operations	$ 4.7	$ 1.2	$ 13.2	$ (0.7)