v3.26.1
Segmented information (Schedule of segments) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure of operating segments [line items]    
Revenue $ 2,211.0 $ 2,021.2
Cost of sales    
Mine operating costs 1,028.1 1,040.8
Depreciation and amortization 439.7 426.6
Gross profit (loss) 743.2 553.8
Selling and administrative expenses 94.7 57.0
Exploration expenses 46.3 42.6
Other operating expenses (income) 7.8 57.4
Re-evaluation adjustment - environmental provision 0.2 (3.5)
Impairment - reversal (322.3) 0.0
Results from operating activities 916.5 400.3
Consideration received from sale of non-core project (14.9) 0.0
Net interest expense on long term debt 60.7 69.8
Accretion on streaming arrangements 19.9 24.2
Change in fair value of financial instruments (52.9) 16.6
Other expenses (8.3) 38.1
Income before tax 912.0 251.6
Tax expense 347.7 183.8
Net income for the year 564.3 67.8
Peru [Member]    
Disclosure of operating segments [line items]    
Revenue 1,161.2 1,049.7
Cost of sales    
Mine operating costs 516.2 517.4
Depreciation and amortization 290.0 270.3
Gross profit (loss) 355.0 262.0
Selling and administrative expenses 0.0 0.0
Exploration expenses 15.9 16.5
Other operating expenses (income) 16.2 15.7
Re-evaluation adjustment - environmental provision 0.0 0.0
Results from operating activities 322.9 229.8
Manitoba [Member]    
Disclosure of operating segments [line items]    
Revenue 748.7 697.4
Cost of sales    
Mine operating costs 273.2 312.6
Depreciation and amortization 86.4 106.2
Gross profit (loss) 389.1 278.6
Selling and administrative expenses 0.0 0.0
Exploration expenses 30.4 24.4
Other operating expenses (income) (8.8) 15.8
Re-evaluation adjustment - environmental provision 0.2 (3.5)
Results from operating activities 367.3 241.9
British Columbia [Member]    
Disclosure of operating segments [line items]    
Revenue 301.1 274.1
Cost of sales    
Mine operating costs 238.7 210.8
Depreciation and amortization 63.3 50.1
Gross profit (loss) (0.9) 13.2
Selling and administrative expenses 0.0 0.0
Exploration expenses 0.0 0.0
Other operating expenses (income) 3.9 17.1
Re-evaluation adjustment - environmental provision 0.0 0.0
Impairment - reversal 0.0  
Results from operating activities (4.8) (3.9)
Arizona [Member]    
Disclosure of operating segments [line items]    
Revenue 0.0 0.0
Cost of sales    
Mine operating costs 0.0 0.0
Depreciation and amortization 0.0 0.0
Gross profit (loss) 0.0 0.0
Selling and administrative expenses 0.0 0.0
Exploration expenses 0.0 0.0
Other operating expenses (income) 0.9 8.3
Re-evaluation adjustment - environmental provision 0.0 0.0
Impairment - reversal (322.3)  
Results from operating activities 321.4 (8.3)
Corporate and other activities [Member]    
Disclosure of operating segments [line items]    
Revenue 0.0 0.0
Cost of sales    
Mine operating costs 0.0 0.0
Depreciation and amortization 0.0 0.0
Gross profit (loss) 0.0 0.0
Selling and administrative expenses 94.7 57.0
Exploration expenses 0.0 1.7
Other operating expenses (income) (4.4) 0.5
Re-evaluation adjustment - environmental provision 0.0 0.0
Impairment - reversal 0.0  
Results from operating activities $ (90.3) $ (59.2)