v3.26.1
Other financial liabilities (Narrative) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Apr. 30, 2025
Disclosure of financial liabilities [line items]      
Net additions $ 39.5 $ 18.6  
Accretion on financial liabilities 6.4 4.7  
Equipment financing [Member]      
Disclosure of financial liabilities [line items]      
Capital additions $ 33.1 $ 71.0  
Equipment financing [Member] | Bottom of range [Member]      
Disclosure of financial liabilities [line items]      
Borrowings, interest rate 2.25%    
Equipment financing [Member] | Top of range [Member]      
Disclosure of financial liabilities [line items]      
Borrowings, interest rate 7.55%    
Constancia Operation [Member]      
Disclosure of financial liabilities [line items]      
Net additions $ 39.5    
Copper Mountain Mine (BC) Ltd. [Member]      
Disclosure of financial liabilities [line items]      
Annual deferred payments recorded as financial liability     $ 16.6
Contingent payments recorded as financial liability     $ 13.3
Accretion on financial liabilities $ 1.4    
Copper Mountain Mine (BC) Ltd. [Member] | Mitsubishi Materials Corporation [Member]      
Disclosure of financial liabilities [line items]      
Percentage of voting equity interests acquired     25.00%
Stream transactions with 777 mine [Member]      
Disclosure of financial liabilities [line items]      
Discount rate on streaming agreement 9.00%