Note 11 - Derivative Instruments (Details Textual) $ in Thousands, CAD in Millions	9 Months Ended
Sep. 30, 2016 USD ($)	Sep. 30, 2016 CAD
Foreign Exchange Forward [Member] \| Designated as Hedging Instrument [Member]
Derivative, Number of Instruments Held	70	70
Foreign Exchange Contract [Member] \| Minimum [Member] \| Casa Berardi [Member] \| United States of America, Dollars
Derivative, Forward Exchange Rate	1.2787	1.2787
Foreign Exchange Contract [Member] \| Maximum [Member] \| Casa Berardi [Member] \| Canada, Dollars
Derivative, Forward Exchange Rate	1.3031	1.3031
Foreign Exchange Contract [Member] \| Other Noncurrent Assets [Member]
Derivative Asset, Noncurrent	$ 48
Foreign Exchange Contract [Member] \| Other Current Liabilities [Member]
Derivative Liability, Current	700
Foreign Exchange Contract [Member] \| Other Noncurrent Liabilities [Member]
Derivative Liability, Noncurrent	900
Unsettled Concentrate Sales Contracts [Member]
Derivative, Loss on Derivative	$ 15,900
Minimum [Member] \| Casa Berardi [Member]
Derivative, Forward Contracts, Forecasted Cash Operating Costs, Percent	20.00%	20.00%
Maximum [Member] \| Casa Berardi [Member]
Derivative, Forward Contracts, Forecasted Cash Operating Costs, Percent	44.00%	44.00%
Other Current Liabilities [Member]
Derivative Liability, Current	$ 600
Other Comprehensive Income (Loss) [Member]
Foreign Currency Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months	(700)
Derivative, Notional Amount	$ 135,900	CAD 175
Maximum Allocation of Forecasted CAD-demonimated Operating Costs	75.00%	75.00%
Forecasted CAD-denominated Operating Costs to be Hedged, Term	5 years
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	$ (1,600)
Gain (Loss) on Components Excluded from Assessment of Foreign Currency Cash Flow Hedge Effectiveness	$ (1)
Maximum Percentage of Forecasted Metal Sales	75.00%	75.00%
Maximum Forecasted Metal Sales to be Hedged, Term	5 years
Derivative Asset, Current	$ 800
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	3,200
Derivative, Fair Value, Obligations Under the Agreements	$ 3,200

The amount of required settlement obligation under the agreements at termination.

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The percentage of the forward contracts of the forecasted cash operating costs.

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Period within which forecasted foreign currency denominated operating costs will be hedged.

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Maximum percentage of foreign currency denominated operating costs to be hedged in the future.

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Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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Accumulated change, net of tax, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after offset of derivative asset, of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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Contractual rate at which a foreign currency can be purchased or sold.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Amount of decrease in the fair value of derivatives recognized in the income statement.

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The number of derivative instruments of a particular group held by the entity.

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The estimated net amount of unrealized gains or losses on foreign currency cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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The net gain (loss) relating to components of the gain (loss) on foreign currency cash flow hedging instruments excluded from the assessment of hedge effectiveness. Recognized in earnings.

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