DERIVATIVE INSTRUMENTS (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Derivative contracts not designated as hedging instruments and their balance sheet location
Derivative instruments, Current assets	$ 5,192	$ 40,190
Derivative instruments, Long-term assets	400	8,335
Derivative instruments, Current liabilities	4,542	9,347
Derivative instruments, Long-term liabilities	0	7,204
Not Designated as Hedging Instrument
Derivative contracts not designated as hedging instruments and their balance sheet location
Derivative instruments, Current assets	5,192	40,190
Derivative instruments, Long-term assets	400	8,335
Not Designated as Hedging Instrument \| Commodity
Derivative contracts not designated as hedging instruments and their balance sheet location
Derivative instruments, Current assets	5,192	28,690
Derivative instruments, Long-term assets	400	6,775
Derivative instruments, Current liabilities	4,542	9,347
Derivative instruments, Long-term liabilities	0	7,204
Not Designated as Hedging Instrument \| Interest rate
Derivative contracts not designated as hedging instruments and their balance sheet location
Derivative instruments, Current assets	0	11,500
Derivative instruments, Long-term assets	$ 0	$ 1,560

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References+ Details

- Definition

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References+ Details

- Definition

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References+ Details