LEASES (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year,	$ 1.9
Finance Lease, Liability, Payments, Remainder of Fiscal Year	$ 5.9
Finance Lease, Weighted Average Remaining Lease Term	5 years
Finance Lease, Interest Payment on Liability	$ 0.2
Finance Lease, Right-of-Use Asset, Amortization	1.7
Capital Lease Obligations	29.0	[1]
Operating Lease, Right-of-Use Asset	19.0	[2]
Operating and Finance lease Right of Use Asset	48.0
Operating Lease, Liability, Current	2.0	[3]
Operating Lease, Liability, Noncurrent	15.0	[4]
Finance Lease, Liability, Current	7.0	[5]
Finance Lease, Liability, Noncurrent	22.0	[6]
Operating and Finance Lease Liability	46.0
Finance Lease, Interest Expense	0.2
Operating Lease, Cost	0.8
Short-term Lease, Cost	0.4
Lease, Cost	3.0
Operating Lease, Payments	0.7
Finance Lease, Principal Payments	$ 1.7
Operating Lease, Weighted Average Remaining Lease Term	23 years
Finance Lease, Weighted Average Discount Rate, Percent	2.91%
Operating Lease, Weighted Average Discount Rate, Percent	4.22%
Lessee, Operating Lease, Liability, Payments, Due Year Two	$ 1.4
Finance Lease, Liability, Payments, Due Year Two	7.4
Lessee, Operating Lease, Liability, Payments, Due Year Three	1.1
Finance Lease, Liability, Payments, Due Year Three	5.7
Lessee, Operating Lease, Liability, Payments, Due Year Four	1.0
Finance Lease, Liability, Payments, Due Year Four	4.4
Operating Leases, Future Minimum Payments Receivable, in Five Years	1.0
Finance Lease, Liability, Payments, Due Year Five	3.1
Lessee, Operating Lease, Liability, Payments, Due after Year Five	22.7
Finance Lease, Liability, Payments, Due in Rolling after Year Five	4.7
Lessee, Operating Lease, Liability, Payments, Due	29.0
Finance Lease, Liability, Payments, Due	31.0
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(12.4)
Finance Lease, Liability, Undiscounted Excess Amount	(2.2)
Operating Lease, Liability	17.0
Finance Lease, Liability	$ 29.0

[1] Included in utility plant, net, in the Consolidated Balance Sheets, net of $18 million of accumulated amortization at March 31, 2019.

[2] Included in other deferred debits and other assets in the Consolidated Balance Sheets.

[3] Included in other current liabilities in the Consolidated Balance Sheets.

[4] Included in other deferred credits and other liabilities in the Consolidated Balance Sheet

[5] Included in current portion of long-term debt in the Consolidated Balance Sheets.

[6] Included in long-term debt in the Consolidated Balance Sheets.