| **DIVESTITURES AND DISCONTINUED OPERATIONS**                                | 6 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
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| **DIVESTITURE AND DISCONTINUED OPERATIONS [Abstract]**                      | Â                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] | DIVESTITURES AND DISCONTINUED OPERATIONSNorth Dakota.During the fourth quarter of 2010, we developed a plan to divest our North Dakota assets. The plan included 100% of our North Dakota assets, consisting of producing wells, undeveloped leaseholds and related facilities primarily located in Burke County. The plan received our Board of Directors' (the "Board") approval and, in December 2010, we effected a letter of intent with an unrelated third party. Following the sale to the unrelated party, we do not have significant continuing involvement in the operations of or cash flows from these assets; accordingly, the North Dakota assets were reclassified as held for sale as of December 31, 2010, and the results of operations related to those assets have been separately reported as discontinued operations in the accompanying financial statements for all periods presented. In February 2011, we executed a purchase and sale agreement and subsequently closed with the same unrelated party. Proceeds from the sale were $9.5 million, net of non-affiliated investor partners' share of $3.8 million, resulting in a pretax gain on sale of $3.9 million.Selected financial information related to divested and discontinued operations. The table below presents selected operational information related to discontinued operations. While the reclassification of revenues and expenses related to discontinued operations for prior period had no impact upon previously reported net earnings, the statement of operations and operational data present the revenues, expenses and production volumes that were reclassified from the specified statement of operations line items to discontinued operations.The following table presents statement of operations data related to our discontinued operations. There was no activity recorded for discontinued operations for the three months ended 2011. The three and six months ended 2010, in addition to the discontinued operations data of our North Dakota assets, includes operations data related to the July 2010 divestiture of our Michigan assets.  Three Months EndedJune 30, Six Months EndedJune 30,Statement of Operations - Discontinued Operations 2010 2011 2010  (dollars in thousands)Revenues      Natural gas, NGL and crude oil sales $1,995 $447 $4,536Sales from natural gas marketing 1,136 — 2,760Well operations, pipeline income and other 146 10 402Total revenues 3,277 457 7,698       Costs, expenses and other      Production costs 864 132 1,579Cost of natural gas marketing 1,197 — 2,728Impairment of proved natural gas and oil properties 4,506 — 4,506Depreciation, depletion and amortization 533 — 1,464Gain on sale of properties and equipment — (3,854) —Total costs, expenses and other 7,100 (3,722) 10,277       Income (loss) from discontinued operations (3,823) 4,179 (2,579)Provision (benefit) for income taxes (1,510) 1,559 (1,063)Income (loss) from discontinued operations, net of tax $(2,313) $2,620 $(1,516)       Operational Data             Production      Natural gas (MMcf) 354.3 8.7 722.8Crude oil (MBbls) 10.6 3.9 22.6Natural gas equivalent (MMcfe) 417.6 32.1 858.0 |

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DIVESTITURE AND DISCONTINUED OPERATIONS [Abstract]
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The entire disclosure for the facts and circumstances leading to the completed or expected disposal, manner and timing of disposal, the gain (loss) recognized in the income statement and the income statement caption that includes that gain (loss), amounts of revenues and pretax profit or loss reported in discontinued operations, the segment in which the disposal group was reported, and the classification (whether sold or classified as held for sale) and carrying value of the assets and liabilities comprising the disposal group. Includes all disposal groups, including those classified as components of the entity (discontinued operations).
+ References
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