ACCRUED LIABILITIES (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Accrued Liabilities, Current [Abstract]
Acquisition-related accruals	$ 90.2	$ 0.0
Accrued compensation and payroll taxes	53.4	40.4
Accrued interest	35.0	4.7
Legal and professional costs	32.0	26.3
Accrued employee benefits	24.4	41.5
Environmental (current portion only)	19.0	19.0
Asset retirement obligation (current portion only)	7.3	10.2
Other	66.8	72.2
Accrued liabilities	$ 328.1	$ 214.3