ENVIRONMENTAL (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Environmental Remediation Obligations [Abstract]
Reserves for future environmental expenditures - total	$ 131.2	$ 136.6	$ 131.6
Reserves for future environmental expenditures - noncurrent	111.2	119.6	$ 111.6
Environmental Remediation Expense	$ 2.3	$ 2.6