Asset Retirement Obligations (Details) - USD ($) |
12 Months Ended | |
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Dec. 31, 2018 |
Dec. 31, 2017 |
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| Change in estimated liability | $ 2,840,000 | $ 448,000 |
| Lost Creek Project | ||
| Estimated Future Cash Undiscounted Amount | 18,400,000 | |
| Change in estimated liability | $ 2,500,000 | $ 613,000 |
| Lost Creek Project | Minimum | ||
| Discount Rate Of Asset Retirement Obligations | 0.10% | |
| Lost Creek Project | Maximum | ||
| Discount Rate Of Asset Retirement Obligations | 3.20% | |
| Pathfinder properties | ||
| Estimated Future Cash Undiscounted Amount | $ 12,000,000 | |
| Pathfinder properties | Minimum | ||
| Discount Rate Of Asset Retirement Obligations | 2.16% | |
| Pathfinder properties | Maximum | ||
| Discount Rate Of Asset Retirement Obligations | 3.00% | |
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- Definition Discount Rate Of Asset Retirement Obligations No definition available.
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- Definition Amount of estimated future cash undiscounted amount. No definition available.
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- Definition Amount of increase (decrease) in the asset retirement obligation from changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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