ENVIRONMENTAL (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Environmental Remediation Obligations [Abstract]
Provisions charged to income	$ 2.5	$ 2.6
Recoveries for costs incurred and expensed	(2.2)	0.0
Environmental expense	0.3	2.6
Reserves for future environmental expenditures - total	147.2	139.1	$ 147.2
Reserves for future environmental expenditures - noncurrent	$ 128.2	$ 122.1	$ 128.2