|**LONG-TERM DEBT LONG-TERM DEBT (Tables)**                                | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
|**Long-term Debt, Unclassified [Abstract]**                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Schedule of Long-term Debt Instruments [Table Text Block]                 | Long-term debt consists of the following:As of December 31,20142013(in thousands)Senior notes:3.25% Convertible senior notes due 2016:Principal amount$115,000$115,000Unamortized discount(6,077)(10,010)3.25% Convertible senior notes due 2016, net of discount108,923104,9907.75% Senior notes due 2022500,000500,000Total senior notes608,923604,990Revolving credit facility56,000—Long-term debt664,923604,990PDCM credit facility—37,000PDCM second lien term loan—15,000PDCM long-term debt (included in liabilities held for sale - non-current)—52,000Total debt$664,923$656,990
|                                                                         
|                                                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|                                                                          | As of December 31,                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
|                                                                          | 2014                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|                                                                          | (in thousands)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
|Senior notes:                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|3.25% Convertible senior notes due 2016:                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Principal amount                                                          | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Unamortized discount                                                      | (6,077                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
|3.25% Convertible senior notes due 2016, net of discount                  | 108,923                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|7.75% Senior notes due 2022                                               | 500,000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Total senior notes                                                        | 608,923                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Revolving credit facility                                                 | 56,000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
|Long-term debt                                                            | 664,923                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|                                                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|PDCM credit facility                                                      | —                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|PDCM second lien term loan                                                | —                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|PDCM long-term debt (included in liabilities held for sale - non-current) | —                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Total debt                                                                | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         

X- Details**Name:**
                    us-gaap_LongTermDebtAbstract**Namespace Prefix:**
                    us-gaap_**Data Type:**
                    xbrli:stringItemType**Balance Type:**
                    na**Period Type:**
                    duration X- DefinitionTabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.+ ReferencesReference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(e),(f)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21521-112644Reference 10: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21538-112644Reference 11: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823+ Details**Name:**
                    us-gaap_ScheduleOfDebtInstrumentsTextBlock**Namespace Prefix:**
                    us-gaap_**Data Type:**
                    nonnum:textBlockItemType**Balance Type:**
                    na**Period Type:**
                    duration