SUPPLEMENTAL CASH FLOW INFORMATION (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Supplemental Cash Flow Information [Abstract]
Interest payments made including amounts capitalized	$ 91.2	$ 82.5	$ 76.0
Cash paid during the period related to floor plan interest	38.6	31.2	22.3
Income taxes paid	48.4	40.4	102.7
Loaner vehicles transferred from other current assets to inventory	141.0	$ 193.9	$ 156.2
Non cash investing and financing activities on previously leased real estate	$ 4.1