|**PROPERTIES AND EQUIPMENT**                                                           | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
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|**PROPERTIES AND EQUIPMENT [Abstract]**                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Capitalized Costs Relating to Oil and Gas Producing Activities Disclosure [Text Block] | PROPERTIES AND EQUIPMENTThe following table presents the components of properties and equipment, net of depreciation and assets held-for-sale.March 31, 2012December 31, 2011(in thousands)Properties and equipment, net:Natural gas and crude oil propertiesProved$1,738,596$1,694,694Unproved132,499102,466Total natural gas and crude oil properties1,871,0951,797,160Pipelines and related facilities42,06240,721Transportation and other equipment32,87832,475Land and buildings13,87214,572Construction in progress61,58469,633Gross properties and equipment2,021,4911,954,561Accumulated DD&A(692,031)(652,845)Properties and equipment, net$1,329,460$1,301,716
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|                                                                                       | March 31, 2012                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|                                                                                       | (in thousands)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|Properties and equipment, net:                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Natural gas and crude oil properties                                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Proved                                                                                 | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
|Unproved                                                                               | 132,499                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Total natural gas and crude oil properties                                             | 1,871,095                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Pipelines and related facilities                                                       | 42,062                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
|Transportation and other equipment                                                     | 32,878                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
|Land and buildings                                                                     | 13,872                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
|Construction in progress                                                               | 61,584                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
|Gross properties and equipment                                                         | 2,021,491                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Accumulated DD&A                                                                       | (692,031                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
|Properties and equipment, net                                                          | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
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                    duration X- DefinitionTabular disclosure of aggregate capitalized costs relating to an enterprise's oil and gas producing activities and the aggregate related accumulated depreciation, depletion, amortization, and valuation allowances.+ ReferencesReference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=6821537&loc=d3e61926-109447Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=6821537&loc=d3e61929-109447Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 19 -Paragraph 59M -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 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=6821537&loc=d3e61901-109447Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 55 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6822203&loc=d3e63019-109448+ Details**Name:**
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