DERIVATIVES (Fair Value of Derivative Instruments) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Designated as Hedging Instrument [Member] | Inventory Supply Arrangement Obligation [Member] | Accrued Expenses [Member]
Derivatives, Fair Value [Line Items]
Fair Value Asset/(Liability)	$ 1,430	$ 4,251
Designated as Hedging Instrument [Member] | Inventory Intermediation Agreement Obligation [Member] | Accrued Expenses [Member]
Derivatives, Fair Value [Line Items]
Fair Value Asset/(Liability)	31,148	94,834
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Accrued Expenses [Member]
Derivatives, Fair Value [Line Items]
Fair Value Asset/(Liability)	(19,389)
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Accounts Receivable [Member]
Derivatives, Fair Value [Line Items]
Fair Value Asset/(Liability)	$ 14,005	$ 31,155