SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Supplemental Cash Flow Information [Abstract]
Interest payments made including amounts capitalized	$ 14,100,000	$ 10,100,000
Cash paid during the period related to floor plan interest	9,800,000	6,300,000
Income taxes paid, net	0	200,000
Loaner vehicles transferred from other current assets to inventory	$ 37,000,000	$ 44,700,000