RESTRUCTURING, CONTRACT EXIT AND PLANT CONVERSION EXPENSES - Additional Information (Details) - Selling, general and administrative expenses - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017
Restructuring Cost And Reserve [Line Items]
Restructuring expenses	$ 5.9	$ 6.6
Employee severance costs	2.0	2.6
Long-lived assets and operating permits impairment charges	3.6	3.6
Other related costs	0.3	0.4
Expenses to exit certain of patient transportation services	1.1	2.5
Plant conversion and other related expenses	7.2	8.0
Operating permits and customer relationships impairment charges	5.5	5.9
Restructuring settlement other costs	$ 1.7	$ 2.1