| **INCOME TAXES Income Taxes (Tables)**                                    | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
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| **Income Tax Disclosure [Abstract]**                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] | The table below presents the components of our provision for income taxes from continuing operations for the years presented: Year Ended December 31, 2015 2014 2013 (in thousands)Current:     Federal$(2,944) $(1,514) $1,355State(163) 966 199Total current income taxes(3,107) (548) 1,554Deferred:     Federal37,352 (60,698) 8,238State4,063 (8,721) 2,060Total deferred income taxes41,415 (69,419) 10,298Income tax benefit (expense) from continuing operations$38,308 $(69,967) $11,852                                                                                                                                                                                                                                                                                                         |
| Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]   | The following table presents a reconciliation of the statutory rate to the effective tax rate related to our provision for income taxes from continuing operations: Year Ended December, 31, 2015 2014 2013      Statutory tax rate35.0 % 35.0 % 35.0 %State income tax, net2.4 2.8 4.0Percentage depletion0.3 (0.3) 2.2Non-deductible compensation(1.2) 0.7 (4.2)Other(0.6) 1.3 (1.0)Effective tax rate35.9 % 39.5 % 36.0 %                                                                                                                                                                                                                                                                                                                                                                                   |
| Schedule of Deferred Tax Assets and Liabilities [Table Text Block]        | The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities at December 31, 2015 and 2014 are presented below:  As of December 31, 2015 2014 (in thousands)Deferred tax assets:   Deferred compensation$13,104 $10,459Asset retirement obligations34,101 28,051State NOL and tax credit carryforwards, net3,376 3,761Alternative minimum tax - credit carryforward2,812 2,906Settlement of class action litigation— 12,259Other3,412 3,144Deferred tax assets56,805 60,580    Deferred tax liabilities:   Properties and equipment99,191 130,155Net change in fair value of unsettled derivatives100,369 113,007Convertible debt697 2,285Total gross deferred tax liabilities200,257 245,447Net deferred tax liability$143,452 $184,867     |

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| - Definition
Tabular disclosure of the components of income tax expense attributable to continuing operations for each year presented including, but not limited to: current tax expense (benefit), deferred tax expense (benefit), investment tax credits, government grants, the benefits of operating loss carryforwards, tax expense that results from allocating certain tax benefits either directly to contributed capital or to reduce goodwill or other noncurrent intangible assets of an acquired entity, adjustments of a deferred tax liability or asset for enacted changes in tax laws or rates or a change in the tax status of the entity, and adjustments of the beginning-of-the-year balances of a valuation allowance because of a change in circumstances that causes a change in judgment about the realizability of the related deferred tax asset in future years.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319
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| - Definition
Tabular disclosure of the components of net deferred tax asset or liability recognized in an entity's statement of financial position, including the following: the total of all deferred tax liabilities, the total of all deferred tax assets, the total valuation allowance recognized for deferred tax assets.
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Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319
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| - Definition
Tabular disclosure of the reconciliation using percentage or dollar amounts of the reported amount of income tax expense attributable to continuing operations for the year to the amount of income tax expense that would result from applying domestic federal statutory tax rates to pretax income from continuing operations.
+ References
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