LEASES - LEASE EXPENSE AND SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Lease expense
Operating lease expense	$ 1.3	$ 1.4	$ 4.1	$ 4.2
Short-term lease expense	0.1	0.1	0.2	0.8
Lease expense	3.5	3.5	10.5	10.8
Amortization of finance lease right of use assets	1.3		3.6
Interest on finance lease liabilities	$ 0.8		2.6
Other information
Operating cash flows from finance/capital leases			2.6	5.8
Operating cash flows from operating leases			4.9	4.9
Financing cash flows from finance leases			3.6	0.0
Right-of-use asset obtained in exchange for finance lease liabilities			28.7
Right of use assets obtained in exchange for operating lease liabilities			$ 49.0
Weighted average remaining lease term - finance leases	31 years 6 months		31 years 6 months
Weighted average remaining lease term - operating leases	13 years		13 years
Weighted average discount rate - finance leases	6.80%		6.80%
Weighted average discount rate - operating leases	4.40%		4.40%
Finance and capital leases
Lease expense
Lease expense	$ 2.1	$ 2.0	$ 6.2	$ 5.8