ENVIRONMENTAL (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Environmental Remediation Obligations [Abstract]
Reserves for future environmental expenditures - total	$ 135.3	$ 137.5	$ 135.3	$ 137.5	$ 137.3
Reserves for environmental expenditures - noncurrent	118.3	118.5	118.3	118.5	$ 120.3
Environmental Remediation Expense	$ 1.8	$ 0.4	$ 6.2	$ 5.5