v3.25.4
FINANCIAL RISK MANAGEMENT AND FINANCIAL INSTRUMENTS - Interest Rate Risk (Details) - CAD ($)
$ / shares in Units, $ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Currency risk    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Expenditure derivatives - change in foreign exchange rate, change in Cdn% relative to US$ (in dollars per share) $ 0.01  
Impact on net income $ 7 $ 0
Impact on other comprehensive income $ 18 12
Interest rate risk | Short-term borrowings    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Short-term borrowings, percent change in interest rates 1.00%  
Impact on net income $ 29 22
Impact on other comprehensive income $ 0 0
Interest rate risk | Bank credit facilities    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Short-term borrowings, percent change in interest rates 1.00%  
Impact on net income $ 3 7
Impact on other comprehensive income $ 0 $ 0
Fixed interest rate | Interest rate risk    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Percent of borrowings 89.10% 90.80%