| **LONG-TERM DEBT LONG-TERM DEBT (Tables)**                | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
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| **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, 2015 2014 (in thousands)Senior notes:   3.25% Convertible senior notes due 2016:   Principal amount$115,000 $115,000Unamortized discount(1,852) (6,077)Unamortized debt issuance costs(208) (765)3.25% Convertible senior notes due 2016, net of discount and unamortized debt issuance costs112,940 108,158    7.75% Senior notes due 2022:   Principal amount500,000 500,000Unamortized debt issuance costs(7,563) (8,683)7.75% Senior notes due 2022, net of unamortized debt issuance costs492,437 491,317Total senior notes605,377 599,475    Revolving credit facility37,000 56,000Total debt, net of discount and unamortized debt issuance costs642,377 655,475Less current portion of long-term debt112,940 —Long-term debt$529,437 $655,475 |

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No definition available.
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| - Definition
Tabular 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.
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