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LONG-TERM DEBT AND FINANCING ARRANGEMENTS (Financing arrangements - Notes payable & Capital leases) (Details) - Notes payable - USD ($) $ in Millions		3 Months Ended	6 Months Ended
	Aug. 01, 2018	Jun. 30, 2018	Jun. 30, 2018
Revenue equipment, other equipment and software
Financing Arrangements
Equipment financed during the period under notes payable		$ 14.3	$ 14.4
Subsequent Event \| Revenue equipment
Financing Arrangements
Equipment financed during the period under notes payable	$ 19.9