DERIVATIVE FINANCIAL INSTRUMENTS (Details Textuals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Jun. 30, 2012	Oct. 31, 2011	Dec. 22, 1997
Derivative [Line Items]
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net	$ 0.0	$ 0.0
CashCollateralProvidedByUsToCounterparties			$ 5.6
Cash flow hedges [Abstract]
Commodity forward contracts with Wells Fargo	35.0
Commodity forward contracts with Citibank	26.6
Cash Flow Hedges Derivative Instruments at Fair Value, Net	6.6
Cash Flow Hedge Gain (Loss) to be Reclassified wihtin Twelve Months	2.7
Fair value hedges [Abstract]
Amount of terminated interest rate swaps				$ 73.1
Gain on terminated interest rate swaps	0.3			$ 2.2
Series O Face Amount						$ 97.5
Series G Face Amount						$ 97.5
Interest Rate on SunBelt Notes						7.23%
Forward Contracts
Derivative [Line Items]
Notional amount	29.6	0.0	21.7
Forward Contracts Sell
Derivative [Line Items]
Notional amount	98.9	0.0	10.1
Variable Interest Rate Swaps $125M
Derivative [Line Items]
Notional amount	125.0
Deferred gain recognized	0.6				$ 11.0
Fixed Interest Rate Swaps $125M
Derivative [Line Items]
Notional amount	125.0
Interest Rate Swaps Designated As Fair Value Hedges
Derivative [Line Items]
Notional amount	$ 0.0	$ 0.0	$ 0.0