v3.26.1
Income and mining taxes (Tables)
 12 Months Ended
Dec. 31, 2025
Major components of tax expense (income) [abstract]  
Disclosure of detailed information about effective income tax expense (recovery) [Table Text Block]
    Year ended December 31,  
    2025     2024  
Current:            
Income taxes $ 209.1   $ 119.7  
Mining taxes   83.4     57.0  
Adjustments in respect of prior years   (1.2 )   0.2  
    291.3     176.9  
Deferred:            
Income tax expense (recovery) - origination, revaluation and/or reversal of temporary differences   61.3     15.3  
Mining tax recovery - origination, revaluation and/or reversal of temporary difference   (3.8 )   (5.6 )
Adjustments in respect of prior years   (1.1 )   (2.8 )
    56.4     6.9  
  $ 347.7   $ 183.8  
Disclosure of detailed information about deferred taxes [Table Text Block]
    Dec. 31, 2025     Dec. 31, 2024  
Deferred income tax asset $ 66.5   $ 102.6  
             
Deferred income tax liability   (343.1 )   (305.5 )
Deferred mining tax liability   (32.2 )   (34.9 )
    (375.3 )   (340.4 )
Net deferred tax liability balance, end of year $ (308.8 ) $ (237.8 )
Disclosure of detailed information about changes in deferred tax assets and liabilities [Table Text Block]
    Year ended December 31,  
    2025     2024  
Net deferred tax liability balance, beginning of year $ (237.8 ) $ (255.3 )
Deferred tax expense (note 24a)   (56.4 )   (6.9 )
OCI transactions   (0.7 )   (3.2 )
Foreign currency translation on the deferred tax liability   (13.9 )   27.6  
Net deferred tax liability balance, end of year $ (308.8 ) $ (237.8 )
Disclosure of detailed information about reconciliation to statutory tax rate [Table Text Block]
    Year ended December 31,  
    2025     2024  
Income before tax $ 912.0   $ 251.6  
Statutory tax rate   26.7%     26.7%  
Tax expense at statutory rate   243.5     67.2  
Effect of:            
Deductions related to mining taxes   (24.2 )   (16.3 )
Adjusted income taxes   219.3     50.9  
Mining tax expense   76.9     50.0  
    296.2     100.9  
             
Permanent differences related to:            
Capital items   (7.4 )   0.5  
Other income tax permanent differences   (0.8 )   4.1  
Withholding tax on dividends   9.0     1.8  
Impact of remeasurement on decommissioning liability   (1.7 )   6.5  
Temporary income tax differences (recognized)/not recognized   (5.4 )   8.3  
Recognition of previously unrecognized deferred tax assets   (2.4 )   -  
Impact related to differences in tax rates in foreign operations   71.6     36.7  
Impact of changes to statutory tax rates   -     (4.4 )
Effect of flow through shares   4.3     3.9  
Foreign exchange on non-monetary items   (15.4 )   26.2  
Impact related to tax assessments and tax return amendments   0.4     (1.2 )
Other   (0.7 )   0.5  
Tax expense $ 347.7   $ 183.8  
Disclosure of temporary differences recognized [Table Text Block]
        Balance sheet  
    Dec. 31, 2025     Dec. 31, 2024  
Deferred income tax (liability) asset            
Property, plant and equipment $ (65.5 ) $ (54.5 )
Pension obligation   2.3     2.0  
Other employee benefits   35.8     25.1  
Decommissioning and restoration provision   24.4     19.3  
Non-capital losses   53.7     107.3  
Share issuance and debt cost   2.9     3.8  
Deferred revenue   1.8     1.7  
Other   11.1     (2.1 )
Deferred income tax asset   66.5     102.6  
             
Deferred income tax liability (asset)            
Property, plant and equipment   526.9     451.6  
Other employee benefits   (1.7 )   (1.2 )
Decommissioning and restoration provision   (12.8 )   (11.8 )
Non-capital losses   (158.7 )   (116.7 )
Other   (10.6 )   (16.4 )
Deferred income tax liability   343.1     305.5  
             
Net deferred income tax liability $ (276.6 ) $ (202.9 )
Disclosure of detailed information about temporary differences - deferred mining tax assets and liabilities [Table Text Block]
Canada   Dec. 31, 2025     Dec. 31, 2024  
Property, plant and equipment $ (40.5 ) $ (40.2 )
Other   13.9     12.8  
  $ (26.6 ) $ (27.4 )
             
Peru   Dec. 31, 2025     Dec. 31, 2024  
Property, plant and equipment $ (5.6 ) $ (7.5 )