ENVIRONMENTAL (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Environmental Remediation Obligations [Abstract]
Provisions charged to income	$ 3.6	$ 12.5	$ 10.8	$ 17.9
Recoveries for costs incurred and expensed	0.0	0.0	(2.2)	0.0
Environmental expense	3.6	12.5	8.6	17.9
Reserves for future environmental expenditures - total	147.7	146.7	147.7	146.7	$ 147.2
Reserves for future environmental expenditures - noncurrent	$ 128.7	$ 129.7	$ 128.7	$ 129.7	$ 128.2