v3.26.1
CAPITAL STOCK - Schedule of Common Shares Purchases (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]        
Aggregate cost (including transaction fees and excluding share buyback taxes) of Common Shares repurchased for cancellation $ 0.0 $ 40.0 $ 20.0 $ 115.0
Number of Common Shares repurchased for cancellation (in shares) 0.0 0.6 0.1 1.2
Weighted average price per share for repurchases (in dollars per share) $ 0 $ 70.48 $ 273.60 $ 94.05
Aggregate cost (including transaction fees) of Common Shares repurchased for delivery under SBC plans $ 0.0 $ 0.0 $ 0.0 $ 221.6
Number of Common Shares repurchased for delivery under SBC plans (in shares) 0.0 0.0 0.0 1.7
NCIB ASPP        
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]        
Number of Common Shares repurchased for cancellation (in shares)   0.6   0.6