v3.26.1
Share Capital (Narrative) (Details)
$ / shares in Units, $ / shares in Units, $ in Millions, $ in Millions
 3 Months Ended 12 Months Ended
Jun. 30, 2024
USD ($)
shares
Jun. 30, 2024
CAD ($)
shares
Dec. 31, 2025
USD ($)
shares
$ / shares
Dec. 31, 2025
$ / shares
Dec. 31, 2024
USD ($)
shares
$ / shares
Dec. 31, 2024
$ / shares
shares
Equity Financing [Line Items]            
Stock Repurchased Authorization | shares         18,580,120 18,580,120
Shares repurchased and cancelled (in shares) | shares 451,990 451,990        
Proceeds from issuance of flow-through shares $ 10.5 $ 14.4 $ 0.0   $ 10.5  
Dividends paid (Note 19)     $ 39.5   $ 35.1  
Weighted average share price for share options in share-based payment arrangement exercised during period at date of exercise | $ / shares       $ 39.52   $ 22.92
Granted (in shares) | shares     275,485   471,177  
Share price (cad per share) | $ / shares       $ 53.00   $ 26.52
Stock repurchased and canceled, value     $ (38.8)   $ 0.0  
Share-based compensation (Note 19(d))     67.6   31.7  
Share-based compensation (Note 19)     55.0   31.7  
Expense from share-based payment transactions with employees     55.0   31.7  
Expense from share-based compensation, capitalized     3.8   0.0  
Cost of sales            
Equity Financing [Line Items]            
Expense from share-based payment transactions with employees     $ 12.6   $ 0.0  
Top of range            
Equity Financing [Line Items]            
Discount rate on prevailing market price from treasury     5.00%      
Restricted share units ("RSU")            
Equity Financing [Line Items]            
Weighted average exercise price of other equity instruments granted in share-based payment arrangement | $ / shares     $ 33.64   $ 16.41  
Deferred share units ("DSU")            
Equity Financing [Line Items]            
Weighted average exercise price of other equity instruments granted in share-based payment arrangement | $ / shares     34.30   16.75  
Performance share units ("PSU")            
Equity Financing [Line Items]            
Weighted average exercise price of other equity instruments granted in share-based payment arrangement | $ / shares     $ 33.59   $ 16.07  
SHARE CAPITAL            
Equity Financing [Line Items]            
Shares repurchased and cancelled (in shares) | shares     (1,326,929)      
Repurchased Shares Price Per Share | $ / shares     $ 29.21      
Dividend reinvestment plan and share purchase plan (in shares) | shares     90,767   349,088  
Shares issued during period, value, DRIP     $ 2.6   $ 5.8  
Shares repurchased     $ (38.8)      
Dividends recognised as distributions to owners         $ 5.8  
Shares issued through share purchase plan (in shares) | shares     252,730   401,537  
Stock repurchased and canceled, value     $ (13.1)   $ 0.0  
RETAINED EARNINGS (DEFICIT)            
Equity Financing [Line Items]            
Dividends recognised as distributions to owners     42.1   40.9  
Stock repurchased and canceled, value     $ 25.7   $ 0.0