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Note 4 - Environmental and Reclamation Activities (Details) - USD ($) $ in Thousands | 1 Months Ended | 12 Months Ended |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Oct. 31, 2013 | Oct. 31, 2012 | Oct. 31, 2011 | Dec. 31, 2015 | Dec. 31, 2014 | Jun. 30, 2015 | Jun. 15, 2015 | Aug. 31, 2014 | Jul. 30, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Note 4 - Environmental and Reclamation Activities (Details) [Line Items] |  |  |  |  |  |  |  |  |  |  |
Other Accrued Liabilities |  |  |  | $ 264,400 |  |  |  |  |  |  |
Payments for Legal Settlements | $ 15,000 | $ 25,000 | $ 168,000 |  |  |  |  |  |  |  |
Payment of Proceeds from Warrants Exercised |  |  |  |  |  |  |  | $ 41,300 | $ 14,100 |  |
Insurance Policy |  |  |  |  |  | $ 16,800 |  |  |  |  |
Environmental Exit Costs, Assets Previously Disposed, Liability for Remediation |  |  |  | 9,900 |  |  |  |  |  |  |
Accrued Reclamation and Closure Costs |  |  |  | 95,538 | $ 57,250 |  |  |  |  | $ 105,191 | $ 113,215
Asset Retirement Obligation, Revision of Estimate |  |  |  | 4,112 | $ 675 |  |  |  |  |  |
Asset Retirement Obligation, Liabilities Incurred |  |  |  | $ 1,189 |  |  |  |  |  |  |
Lucky Friday [Member] |  |  |  |  |  |  |  |  |  |  |
Note 4 - Environmental and Reclamation Activities (Details) [Line Items] |  |  |  |  |  |  |  |  |  |  |
Risk-free Interest Rate |  |  |  | 14.50% |  |  |  |  |  |  |
Asset Retirement Obligation, Revision of Estimate Before Discounting |  |  |  | $ 7,300 |  |  |  |  |  |  |
Asset Retirement Obligation, Revision of Estimate |  |  |  | $ 4,100 |  |  |  |  |  |  |
Inflation Rate |  |  |  | 2.25% |  |  |  |  |  |  |
San Sebastian Unit [Member] |  |  |  |  |  |  |  |  |  |  |
Note 4 - Environmental and Reclamation Activities (Details) [Line Items] |  |  |  |  |  |  |  |  |  |  |
Asset Retirement Obligation, Liabilities Incurred Before Discounting |  |  |  | $ 1,500 |  |  |  |  |  |  |
Asset Retirement Obligation, Liabilities Incurred |  |  |  | $ 1,200 |  |  |  |  |  |  |
Revett Mining Company Inc [Member] |  |  |  |  |  |  |  |  |  |  |
Note 4 - Environmental and Reclamation Activities (Details) [Line Items] |  |  |  |  |  |  |  |  |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Reclamation Liability |  |  |  |  |  | 17,500 | $ 17,513 |  |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed Reclamation Insurance Asset |  |  |  |  |  | $ 16,800 | $ 16,800 |  |  |  |
Revett Mining Company Inc [Member] | Mining Properties and Mineral Rights [Member] |  |  |  |  |  |  |  |  |  |  |
Note 4 - Environmental and Reclamation Activities (Details) [Line Items] |  |  |  |  |  |  |  |  |  |  |
Ownership Percentage |  |  |  |  |  | 100.00% |  |  |  |  |
Minimum [Member] |  |  |  |  |  |  |  |  |  |  |
Note 4 - Environmental and Reclamation Activities (Details) [Line Items] |  |  |  |  |  |  |  |  |  |  |
Risk-free Interest Rate |  |  |  |  | 6.00% |  |  |  |  |  |
Maximum [Member] |  |  |  |  |  |  |  |  |  |  |
Note 4 - Environmental and Reclamation Activities (Details) [Line Items] |  |  |  |  |  |  |  |  |  |  |
Risk-free Interest Rate |  |  |  |  | 14.50% |  |  |  |  |  |

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