PENSION AND OTHER POST-EMPLOYMENT BENEFITS (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
PENSIONS AND OTHER POSTRETIREMENT BENEFITS
Pension settlement charge	$ 1.6	$ 0.7
Pension Benefits
PENSIONS AND OTHER POSTRETIREMENT BENEFITS
Interest cost	1.1	1.5
Expected return on plan assets	(2.3)	(2.7)
Amortization of prior service credit	0.0	0.0
Recognized actuarial loss	0.4	0.3
Pension settlement charge	1.6	0.7
Net periodic benefit cost (credit)	0.8	(0.2)
Other Benefits
PENSIONS AND OTHER POSTRETIREMENT BENEFITS
Interest cost	0.1	0.0
Expected return on plan assets	0.0	0.0
Amortization of prior service credit	(0.1)	0.0
Recognized actuarial loss	0.0	0.0
Pension settlement charge	0.0	0.0
Net periodic benefit cost (credit)	$ 0.0	$ 0.0