PENSION AND POST-RETIREMENT BENEFITS - Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Net periodic benefit costs:
Total net periodic benefit costs	$ 1.1	$ 1.3	$ 4.8
Pension Plans
Net periodic benefit costs:
Service cost	0.3	0.3
Interest cost	2.7	2.3
Expected return on plan assets	(4.9)	(4.9)
Amortization of actuarial loss	2.8	3.4
Total net periodic benefit costs	0.9	1.1
Other Post-Retirement Benefit Plans
Net periodic benefit costs:
Service cost	0.0	0.0
Interest cost	0.1	0.0
Expected return on plan assets	0.0	0.0
Amortization of actuarial loss	0.1	0.2
Total net periodic benefit costs	$ 0.2	$ 0.2