LEASES - Components of assets and liabilities (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Components of assets and liabilities for operating and finance leases
Right-of-use assets	$ 95.9
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Right-of-use assets
Finance lease right-of-use assets	$ 25.3
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other Assets, Noncurrent
Total lease assets	$ 121.2
Current	$ 27.3
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other Liabilities, Current
Non-current	$ 77.8
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other Liabilities, Noncurrent
Present value of lease liabilities	$ 105.1
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesCurrent us-gaap:OtherLiabilitiesNoncurrent
Current	$ 6.2
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Long-term Debt, Current Maturities
Non-current	$ 19.3
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Long Term Debt Excluding Line Of Credit Noncurrent
Total finance lease liabilities	$ 25.5
Total lease liabilities	130.6
Operating cash flows from capitalized operating leases	(35.6)
Operating cash flows from finance leases	(0.9)
Financing cash flows from finance leases	(5.9)
Capitalized operating lease right-of-use assets	39.2
Finance lease right-of-use assets	$ 13.1