LEASES - Balance Sheet Classification (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
ASSETS
Operating lease assets	$ 69.8
Finance lease assets	91.5
Capital leased assets, net		$ 85.4
Total lease assets	161.3
Current liabilities:
Operating	12.9
Finance	24.2
Finance		20.2
Long-term liabilities:
Operating	59.7
Finance	43.1
Finance		51.0
Present value of lease liabilities	139.9	71.2
Finance lease assets, accumulated amortization	$ 29.4
Capital leased assets, gross		103.2
Capital leased assets, accumulated amortization		236.1
Capital Lease Obligations
Long-term liabilities:
Capital leased assets, accumulated amortization		$ 17.8