v3.26.3
Note 8 - Derivative Instruments (Details Textual)
oz in Thousands, $ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
USD ($)
Contract
Sep. 30, 2025
USD ($)
Sep. 30, 2026
USD ($)
Contract
oz
Sep. 30, 2025
USD ($)
Sep. 30, 2026
CAD ($)
Contract
Derivative [Line Items]          
Maximum Allocation of Forecasted CAD-demonimated Operating Costs 75.00%   75.00%   75.00%
General Fair Value Hedge Information Minimum R Square 100.00%   100.00%   100.00%
Description of hedge activity     Within this five year period our policy also allows us to hedge up to 100% of a specific exposure, provided the structure of the derivative instrument allows us to participate 100% in the upside. Our program also utilizes derivatives to manage price risk exposure created from the date when revenue is recognized from a shipment of concentrate until final settlement.    
Forecasted CAD-denominated Operating Costs to be Hedged, Term (Year)     5 years    
Unrealized Gain (Loss) on Derivatives $ 6,800,000   $ 14,400,000    
Price Risk Cash Flow Hedge Unrealized Gain (Loss) to be Reclassified During Next 12 Months 17,500,000   17,500,000    
Derivative, Gain (Loss) on Derivative, Net, Total (13,200,000) $ (8,500,000) $ (13,500,000) $ (9,800,000)  
Derivative instrument gold put option purchased | oz     3,292    
Assets Needed for Immediate Settlement, Aggregate Fair Value 50   $ 50    
Casa Berardi [Member]          
Derivative [Line Items]          
Other Adjustments To Income Discontinued Operations   700,000   3,500,000  
Realized losses     900,000    
Foreign Exchange Forward [Member]          
Derivative [Line Items]          
Derivative, Notional Amount $ 3,500,000   $ 3,500,000    
Derivative, Forward Exchange Rate 0.0139   0.0139   0.0139
Derivative, Gain (Loss) on Derivative, Net, Total $ 100,000 2,000,000 $ 2,600,000 3,500,000  
Foreign Exchange Forward [Member] | Keno Hill [Member]          
Derivative [Line Items]          
Derivative, Notional Amount         $ 35.3
Cash Operating Expenditure $ 80,100,000   $ 80,100,000    
Derivative, Forward Exchange Rate 0.013895   0.013895   0.013895
Exchange Rate 0.013915   0.013915   0.013915
Foreign Exchange Forward [Member] | Casa Berardi and Keno Hill [Member]          
Derivative [Line Items]          
Derivative, Notional Amount $ 4,900,000   $ 4,900,000    
Foreign Exchange Forward [Member] | Casa Berardi and Keno Hill [Member]          
Derivative [Line Items]          
Derivative, Forward Exchange Rate 0.013903   0.013903   0.013903
Foreign Exchange Forward [Member] | Designated as Hedging Instrument [Member] | Casa Berardi [Member]          
Derivative [Line Items]          
Derivative, Number of Instruments Held, Total | Contract 143   143   143
Derivative, Notional Amount $ 89,000,000   $ 89,000,000   $ 123.8
Price Risk Derivative [Member]          
Derivative [Line Items]          
AOCI, Cash Flow Hedge, Cumulative Gain (Loss), after Tax 23,800,000   23,800,000    
Settlement Under Collars [Member]          
Derivative [Line Items]          
Derivative, Gain (Loss) on Derivative, Net, Total 300,000 6,300,000 9,500,000 6,500,000  
Unsettled Concentrate Sales Contracts [Member]          
Derivative [Line Items]          
Derivative, Gain (Loss) on Derivative, Net, Total 13,200,000 14,000,000 13,500,000 16,000,000  
Price Risk Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net 3,200,000 5,100,000 1,600,000 10,800,000  
Final Settlement Concentrate Sales Contracts          
Derivative [Line Items]          
Derivative, Gain (Loss) on Derivative, Net, Total 6,200,000 $ 19,500,000 200,000 $ 31,800,000  
Commodity Contract [Member]          
Derivative [Line Items]          
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral, Total 27,900,000   27,900,000    
Derivative, Fair Value, Obligations Under the Agreements $ 27,900,000   $ 27,900,000