Mineral Properties - rollforward (Details) - USD ($) $ in Thousands |
6 Months Ended | 12 Months Ended |
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Jun. 30, 2017 |
Dec. 31, 2016 |
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Balance at beginning of period | $ 47,029 | |
Increase in reclamation costs | 816 | |
Change in estimated reclamation costs (Note 13) | 815 | $ (534) |
Amortization | (1,515) | |
Balance at end of period | 46,336 | 47,029 |
Lost Creek Property | ||
Balance at beginning of period | 14,016 | |
Increase in reclamation costs | 614 | |
Amortization | (1,515) | |
Balance at end of period | 13,115 | 14,016 |
Path Finder Mines [Member] | ||
Balance at beginning of period | 19,866 | |
Increase in reclamation costs | 202 | |
Balance at end of period | 20,068 | 19,866 |
Other U.S. Properties [Member] | ||
Balance at beginning of period | 13,147 | |
Balance at end of period | $ 13,153 | $ 13,147 |
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- Definition The assumption amount in estimated asset reclamation obligation. No definition available.
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- Definition The aggregate amount of recurring noncash expense charged against earnings in the period to allocate the cost of assets over their estimated remaining economic lives. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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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- Definition Mineral properties, net of adjustments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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