v3.26.1
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS - Schedule of Credit Concentrations and Maximum Credit Exposure, With Respect to Derivative Instruments (Details) - Derivative Instruments - CAD ($)
$ in Millions
3 Months Ended 12 Months Ended
Mar. 31, 2026
Dec. 31, 2025
LIQUIDITY RISK AND CREDIT RISK    
Maximum credit exposure with respect to derivative instruments $ 1,816 $ 858
Canadian financial institutions    
LIQUIDITY RISK AND CREDIT RISK    
Maximum credit exposure with respect to derivative instruments 175 200
US financial institutions    
LIQUIDITY RISK AND CREDIT RISK    
Maximum credit exposure with respect to derivative instruments 1,152 260
European financial institutions    
LIQUIDITY RISK AND CREDIT RISK    
Maximum credit exposure with respect to derivative instruments 65 57
Asian financial institutions    
LIQUIDITY RISK AND CREDIT RISK    
Maximum credit exposure with respect to derivative instruments 49 39
Other    
LIQUIDITY RISK AND CREDIT RISK    
Maximum credit exposure with respect to derivative instruments $ 375 $ 302