PENSION AND OTHER POST-EMPLOYMENT BENEFITS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Sep. 30, 2020	Sep. 30, 2019
PENSIONS AND OTHER POSTRETIREMENT BENEFITS
Pension settlement charge				$ 2.8	$ 10.4
Weighted-average expected long-term rate of return on plan assets	5.75%		6.40%
Pension Benefits
PENSIONS AND OTHER POSTRETIREMENT BENEFITS
Interest cost	$ 1.2	$ 2.5		4.3	7.4
Expected return on plan assets	(2.5)	(3.9)		(7.8)	(11.9)
Amortization of prior service credit	0.0	0.0		0.0	0.0
Recognized actuarial loss	0.4	0.1		1.0	0.4
Pension settlement charge	1.3	9.8		2.8	10.4
Net periodic benefit cost (credit)	0.4	8.5		0.3	6.3
Other Benefits
PENSIONS AND OTHER POSTRETIREMENT BENEFITS
Interest cost	0.0	(0.1)		0.1	0.1
Expected return on plan assets	0.0	0.0		0.0	0.0
Amortization of prior service credit	0.0	(0.1)		(0.2)	(0.5)
Recognized actuarial loss	0.0	0.0		0.0	0.0
Pension settlement charge	0.0	0.0		0.0	0.0
Net periodic benefit cost (credit)	$ 0.0	$ (0.2)		$ (0.1)	$ (0.4)