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Note 11 - Derivative Instruments (Details Textual) $ in Thousands, MXN in Millions, CAD in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2017 USD ($) | Jun. 30, 2016 USD ($) | Jun. 30, 2017 USD ($) | Jun. 30, 2016 USD ($) | Jun. 30, 2017 CAD | Jun. 30, 2017 MXN
Maximum Allocation of Forecasted CAD-demonimated Operating Costs | 75.00% |  | 75.00% |  | 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 | $ 48 |  | $ 48 |  |  |
Gain (Loss) on Sale of Derivatives | 2,487 | $ (6) | (5,322) | $ (6) |  |
Gain (Loss) on Components Excluded from Assessment of Foreign Currency Cash Flow Hedge Effectiveness |  |  | 2 |  |  |
Derivative Liability, Fair Value, Amount Not Offset Against Collateral | 3,200 |  | 3,200 |  |  |
Derivative, Fair Value, Obligations Under the Agreements | 3,200 |  | 3,200 |  |  |
Cost of Sales [Member] |  |  |  |  |  |
Gain (Loss) on Sale of Derivatives |  |  | (400) |  |  |
Other Comprehensive Income (Loss) [Member] |  |  |  |  |  |
Foreign Currency Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months | 400 |  | 400 |  |  |
Foreign Exchange Contract [Member] | Other Current Assets [Member] |  |  |  |  |  |
Derivative Asset, Current | 1,100 |  | 1,100 |  |  |
Foreign Exchange Contract [Member] | Other Noncurrent Assets [Member] |  |  |  |  |  |
Derivative Asset, Noncurrent | 1,100 |  | 1,100 |  |  |
Foreign Exchange Contract [Member] | Other Current Liabilities [Member] |  |  |  |  |  |
Derivative Liability, Current | 400 |  | 400 |  |  |
Foreign Exchange Contract [Member] | Other Noncurrent Liabilities [Member] |  |  |  |  |  |
Derivative Liability, Noncurrent | $ 100 |  | $ 100 |  |  |
Foreign Exchange Contract [Member] | Casa Berardi [Member] | Minimum [Member] | United States of America, Dollars |  |  |  |  |  |
Derivative, Forward Exchange Rate | 1.2787 |  | 1.2787 |  | 1.2787 | 1.2787
Foreign Exchange Contract [Member] | Casa Berardi [Member] | Maximum [Member] | United States of America, Dollars |  |  |  |  |  |
Derivative, Forward Exchange Rate | 1.338 |  | 1.338 |  | 1.338 | 1.338
Foreign Exchange Contract [Member] | San Sebastian [Member] | Minimum [Member] | United States of America, Dollars |  |  |  |  |  |
Derivative, Forward Exchange Rate | 19.3752 |  | 19.3752 |  | 19.3752 | 19.3752
Foreign Exchange Contract [Member] | San Sebastian [Member] | Maximum [Member] | United States of America, Dollars |  |  |  |  |  |
Derivative, Forward Exchange Rate | 21 |  | 21 |  | 21 | 21
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member] | Casa Berardi [Member] |  |  |  |  |  |
Derivative, Number of Instruments Held | 106 |  | 106 |  | 106 | 106
Derivative, Notional Amount | $ 177,000 |  | $ 177,000 |  | CAD 230.1 |
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member] | San Sebastian [Member] |  |  |  |  |  |
Derivative, Number of Instruments Held | 12 |  | 12 |  | 12 | 12
Derivative, Notional Amount | $ 4,800 |  | $ 4,800 |  |  | MXN 96
Commodity Contract [Member] | Other Current Assets [Member] |  |  |  |  |  |
Derivative Asset, Current | 1,200 |  | 1,200 |  |  |
Commodity Contract [Member] | Other Current Liabilities [Member] |  |  |  |  |  |
Derivative Liability, Current | 1,300 |  | 1,300 |  |  |
Commodity Contract [Member] | Other Noncurrent Liabilities [Member] |  |  |  |  |  |
Derivative Liability, Noncurrent | $ 100 |  | 100 |  |  |
Unsettled Concentrate Sales Contracts [Member] |  |  |  |  |  |
Derivative, Loss on Derivative |  |  | 3,300 |  |  |
Forecasted Future Concentrate Contracts [Member] |  |  |  |  |  |
Derivative, Loss on Derivative |  |  | $ 5,300 |  |  |

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- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
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- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=84228862&loc=SL7669646-108580 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e637-108580 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=84228862&loc=SL7669686-108580 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e681-108580 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80784-113994 + Details
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- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13433-108611 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13495-108611 + Details
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