v3.26.1
Note 10 - Fair Value Measurement - Assets and Liabilities Accounted for at Fair Value (Details) - Fair Value, Recurring [Member] - USD ($)
$ in Thousands
Jun. 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 $ 483,482 $ 241,558
Equity securities 154,401 107,486
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 127,416 170,230
Foreign exchange contracts 306 1,127
Metal forward contracts 10,371 15,840
Foreign exchange contracts 2,100 829
Metal forward contracts $ 12,138 $ 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 $ 4,210 $ 0