DERIVATIVE INSTRUMENTS 2 (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Fair value Derivative Assets	$ 71,319	$ 82,778
Fair value Derivative Liabilities	119,110	106,800
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Fair value Derivative Assets	71,319	82,778
Fair value Derivative Liabilities	119,110	106,800
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Derivatives-Energy Related-Current [Member]
Derivatives, Fair Value [Line Items]
Fair value Derivative Assets	58,213	56,327
Fair value Derivative Liabilities	93,123	77,993
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Derivatives-Energy Related-NonCurrent [Member]
Derivatives, Fair Value [Line Items]
Fair value Derivative Assets	13,106	26,451
Fair value Derivative Liabilities	17,247	22,131
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Derivatives-Other [Member]
Derivatives, Fair Value [Line Items]
Fair value Derivative Assets	0	0
Fair value Derivative Liabilities	$ 8,740	$ 6,676