DERIVATIVE FINANCIAL INSTRUMENTS (Details 2) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Derivatives, Fair Value [Line Items]
Asset derivatives	$ 7.0	$ 15.9	$ 9.4
Liability derivatives	16.7	10.2	19.3
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives	0	7.5	0
Liability derivatives	16.5	10.2	18.3
Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives	0	0	0
Designated as Hedging Instrument [Member] | Interest Rate Contract Loss [Member] | Long-term Debt [Member]
Derivatives, Fair Value [Line Items]
Liability derivatives	8.8	10.2	11.6
Designated as Hedging Instrument [Member] | Commodity Contracts Gains [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability derivatives	(1.5)	0	(2.0)
Designated as Hedging Instrument [Member] | Commodity Contracts Gains [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives	0	9.6	0
Designated as Hedging Instrument [Member] | Commodity Contracts Losses [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability derivatives	9.2	0	8.7
Designated as Hedging Instrument [Member] | Commodity Contracts Losses [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives	0	(2.1)	0
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives	7.0	8.4	9.4
Liability derivatives	0.2	0	1.0
Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives	8.5	11.9	12.1
Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability derivatives	0	0	0
Not Designated as Hedging Instrument [Member] | Interest Rate Contract Loss [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives	(1.5)	(3.6)	(2.7)
Not Designated as Hedging Instrument [Member] | Interest Rate Contract Loss [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability derivatives	0	0	0
Not Designated as Hedging Instrument [Member] | Commodity Contracts Gains [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability derivatives	(0.1)	0	(0.1)
Not Designated as Hedging Instrument [Member] | Commodity Contracts Gains [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives	0	0.1	0
Not Designated as Hedging Instrument [Member] | Commodity Contracts Losses [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability derivatives	0.3	0	1.1
Not Designated as Hedging Instrument [Member] | Commodity Contracts Losses [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives	$ 0	$ 0	$ 0