LEASES AND PROPERTY, PLANT AND EQUIPMENT - Lease Cost and Other Information (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Finance Lease Cost:
Amortization of ROU assets	$ 0.1	$ 0.0
Interest on lease liabilities	0.0	0.0
Operating Lease Cost	13.0	10.6
Total Lease Cost	13.1	10.6
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from finance leases	0.0	0.0
Operating cash flows from operating leases	9.9	11.0
Financing cash flows from finance leases	0.1	$ 0.2
ROU assets for finance leases	0.9		$ 1.0
ROU assets for operating leases	90.8		91.4
Accumulated amortization on ROU assets for finance leases	0.4		0.3
Accumulated amortization on ROU assets for operating leases	$ 26.3		$ 23.2
Weighted-average remaining lease term - finance leases	2 years 7 months 6 days		2 years 9 months 18 days
Weighted-average remaining lease term - operating leases	6 years		6 years 2 months 12 days
Weighted-average discount rate - finance leases	15.00%		15.60%
Weighted-average discount rate - operating leases	15.70%		15.80%