v3.26.1
Income taxes (Details) - CAD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Taxable temporary differences associated with investments in subsidiaries, for which deferred tax liabilities have not been recognized $ 0 $ 4,100
Temporary difference which are not recognized as deferred tax assets $ 171,095 186,817
Tax loss utilization limitation percentage 80.00%  
Non-capital losses carried forward    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Temporary difference which are not recognized as deferred tax assets $ 125,723 109,996
Non-capital losses carried forward | Canada    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Temporary difference which are not recognized as deferred tax assets 549,000 470,000
Non-capital losses carried forward | United States    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Temporary difference which are not recognized as deferred tax assets 47,000 61,600
Unrealized losses on investments    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Temporary difference which are not recognized as deferred tax assets 1,113 2,232
Inventories    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Temporary difference which are not recognized as deferred tax assets   6,437
Mining interests and property, plant and equipment    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Temporary difference which are not recognized as deferred tax assets 3,376 29,538
Mineral stream interests - Mexico    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Temporary difference which are not recognized as deferred tax assets   11,051
Environmental rehabilitation provision    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Temporary difference which are not recognized as deferred tax assets 21,095 16,332
Other    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Temporary difference which are not recognized as deferred tax assets $ 19,788 $ 11,231