DERIVATIVE FINANCIAL INSTRUMENTS (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Amount of gains (losses) recognized in income from derivative instruments not designated as hedging instruments
Total	$ (2,975)	$ (2,726)	$ 1,528
Commodity derivatives \| Not designated as hedging instruments
Amount of gains (losses) recognized in income from derivative instruments not designated as hedging instruments
Realized cash settlements on hedges	(2,780)	(12,216)	2,745
Unrealized gain (loss) on hedges	(195)	9,490	(1,217)
Total	$ (2,975)	$ (2,726)	$ 1,528

The difference between the book value and the sale price of options, swaps, futures, forward contracts, and other derivative instruments. This element refers to the gain (loss) included in earnings.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.13(h))

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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