LONG-TERM DEBT AND FINANCING ARRANGEMENTS (Financing arrangements - Notes payable & Capital leases) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2017
Revenue equipment and software \| Notes payable
Financing Arrangements
Equipment financed during the period under notes payable	$ 23.0	$ 61.6

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