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Divestitures and Assets Held for Sale Fair Value of Acquired Properties (Tables) | 12 Months Ended
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Dec. 31, 2014
Fair Value Disclosures [Abstract] |
Schedule of Fair Value of Net Assets Acquired [Table Text Block] |
| As of September 24, 2014 |  | As of October 15, 2014
Purchase Price | (in thousands)
Cash consideration | $ | 325,230 |  |  | $ | 84,836 |
Fair value of assets acquired: |  |  |
Proved oil and gas properties | $ | 203,493 |  |  | $ | 54,360 |
Unproved oil and gas properties | 126,622 |  |  | 29,469 |
Total fair value of oil and gas properties acquired | 330,115 |  |  | 83,829 |
Working capital | (2,772 | ) |  | 2,625 |
Asset retirement obligation | (2,113 | ) |  | (1,618 | )
Total fair value of net assets acquired | $ | 325,230 |  |  | $ | 84,836 |

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