LEASES - LEASE EXPENSE AND SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Lease expense
Operating lease expense	$ 1.4	$ 1.4
Short-term lease expense	0.0	0.1
Lease expense	3.4	3.4
Amortization of finance lease right of use assets	1.1
Interest on finance lease liabilities	0.9
Other information
Operating cash flows from finance/capital lease	0.9	1.9
Operating cash flows from operating leases	1.7	1.7
Financing cash flows from finance lease	1.2	0.0
Noncash activity - right of use assets obtained in exchange for new operating lease liabilities	$ 49.0
Remaining lease term - finance lease	3 years 2 months
Weighted average remaining lease term - operating leases	13 years 2 months
Discount rate - finance lease	15.80%
Weighted average discount rate - operating leases	4.60%
Finance and capital leases
Lease expense
Lease expense	$ 2.0	$ 1.9