v3.26.3
Note 10 - Fair Value Measurement - Assets and Liabilities Accounted for at Fair Value (Details) - Fair Value, Recurring [Member] - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Fair Value, Inputs, Level 1 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Money market funds and other bank deposits $ 691,569 $ 241,558
Equity securities 121,155 107,486
Certificates of deposit and other deposits 1,170 1,174
Fair Value, Inputs, Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Receivables from provisional concentrate sales 134,250 170,230
Foreign exchange contracts 159 1,127
Metal forward contracts 0 15,840
Foreign exchange contracts 1,164 829
Metal forward contracts $ 22,399 $ 38,273
Derivative Liability, Statement of Financial Position [Extensible Enumeration] Liabilities Liabilities
Fair Value, Inputs, Level 2 [Member] | Gold    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Metal forward contracts $ 5,778 $ 0