| **ACQUISITIONS Additional Information (Details) (USD $)**                                                                                                                                                                                           | 12 Months Ended |               |        |             |     | 12 Months Ended |            |            | 12 Months Ended |             |            | 12 Months Ended |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|---------------|--------|-------------|-----|-----------------|------------|------------|-----------------|-------------|------------|-----------------|
||
| **Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]**                                                                                                                                          |            |          |   |        |     |            |       |       |            |        |       |            |   |   |   |   |   |   |   |   |   |
| Acquisition Costs, Cumulative                                                                                                                                                                                                                       |            |          |   |        |     |            |       |       |            |        |       | $ 139,200,000   |   |   |   |   |   |   |   |   |   |
| Aggregate purchase price                                                                                                                                                                                                                            |            |          |   | 304,643,000 | [1] | 69,618,000      | 29,960,000 | 43,015,000 | 34,768,000      | 114,273,000 | 69,618,000 |            |   |   | 36,500,000 |   | 39,400,000 |   |   |   |   |
| Title defect reimbursements                                                                                                                                                                                                                         | 14,469,000      | 0             | 0      |        |     |            |       |       |            |        |       | 28,900,000      |   |   |   |   |   |   |   |   |   |
| Draw on credit facility to purchase Permian Basin assets                                                                                                                                                                                            |            |          |   |        |     |            |       |       |            |        |       |            |   |   |   |   |   | 55,700,000 |   |   |   |
| Gain on sale of Michigan assets                                                                                                                                                                                                                     |            |          |   |        |     |            |       |       |            |        |       |            |   |   |   | 19,200,000 |   |   | (19,920,000) | (3,854,000) | 0 |
| Michigan Divestiture Tax Liability                                                                                                                                                                                                                  |            |          |   |        |     |            |       |       |            |        |       |            |   |   |   | 7,300,000 |   |   |   |   |   |
| Proceeds from Michigan Divestiture                                                                                                                                                                                                                  |            |          |   |        |     |            |       |       |            |        |       |            | 19,300,000 |   |   |   |   |   |   |   |   |
| Michigan Assets Deferred Tax Liabilities                                                                                                                                                                                                            | $ 112,276,000   | $ 191,446,000 |   |        |     |            |       |       |            |        |       |            |   | $ 6,500,000 |   |   |   |   |   |   |   |
|                                                                                                                                                                                                                                                     |
| [1]Assets acquired and liabilities assumed in the Merit Acquisition are subject to post-closing adjustments as more detailed analyses are completed and additional information is obtained about the acquired natural gas and crude oil properties. |

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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The capitalized costs incurred (excluded from amortization), as of the date of the balance sheet, to purchase, lease or otherwise acquire an unproved property, including costs of lease bonuses and options to purchase or lease properties, the portion of costs applicable to minerals when land including mineral rights is purchased in fee, brokers' fees, recording fees, legal costs, and other costs incurred in acquiring properties.
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| - Definition
Amount of cash paid to acquire the entity.
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| - Definition
The total purchase price of the acquired entity. This includes cash paid to equity interest holders of the acquired entity, fair value of debt and equity securities issued to equity holders of the acquired entity, and transaction costs paid to third parties to consummate the acquisition.
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| - Definition
Amount of deferred tax liability attributable to taxable temporary differences net of deferred tax asset attributable to deductible temporary differences and carryforwards after valuation allowances.
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of gain (loss), before tax expense or benefit and not previously recognized, resulting from the sale of a business component.
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Tax effect allocated to a disposal group that is classified as a component of the entity reported as a separate component of income before extraordinary items. Includes the tax effects of the following: income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The net cash inflow or outflow associated with the aggregate amount of adjustment to the purchase price of a previous acquisition.
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash inflow to dispose of long-lived, physical assets and mineral interests in oil and gas properties used for normal oil and gas operations.
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