Asset Retirement Obligations (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Change in estimated liability | $ (534) | $ 2,101 |
| Lost Creek Property | ||
| Estimated Future Cash Undiscounted Amount | 15,000 | |
| Change in estimated liability | $ 338 | 2,391 |
| Lost Creek Property | Minimum | ||
| Discount Rate Of Asset Retirement Obligations | 0.10% | |
| Lost Creek Property | Maximum | ||
| Discount Rate Of Asset Retirement Obligations | 3.20% | |
| Path Finder Mines [Member] | ||
| Estimated Future Cash Undiscounted Amount | $ 11,500 | |
| Change in estimated liability | $ (872) | $ (290) |
| Path Finder Mines [Member] | Minimum | ||
| Discount Rate Of Asset Retirement Obligations | 2.16% | |
| Path Finder Mines [Member] | Maximum | ||
| Discount Rate Of Asset Retirement Obligations | 3.00% | |
| X | ||||||||||
- Definition Discount Rate Of Asset Retirement Obligations No definition available.
|
| X | ||||||||||
- Definition Amount of estimated future cash undiscounted amount. No definition available.
|
| X | ||||||||||
- Definition Amount of the Increase or Decrease in the amount of the asset retirement obligation during the current period for 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
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|