PROPERTY, PLANT AND EQUIPMENT - Lease Disclosure (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finance Lease Cost:
Amortization of ROU assets	$ 0.3	$ 0.3
Interest on lease liabilities	0.1	0.2
Operating Lease Cost	38.9	41.7
Total Lease Cost	39.3	42.2
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from finance leases	0.1	0.2
Operating cash flows from operating leases	36.3	39.4
Financing cash flows from finance leases	0.2	0.8
ROU assets for finance leases	0.6	1.0
ROU assets for operating leases	86.3	91.4
Accumulated amortization on ROU assets for finance leases	0.6	0.3
Accumulated amortization on ROU assets for operating leases	$ 39.9	$ 23.2
Weighted-average remaining lease term - finance leases	2 years 1 month 6 days	2 years 9 months 18 days
Weighted-average remaining lease term - operating leases	6 years 6 months	6 years 2 months 12 days
Weighted-average discount rate - finance leases	15.00%	15.60%
Weighted-average discount rate - operating leases	15.80%	15.80%