v3.26.3
RISK MANAGEMENT AND FINANCIAL INSTRUMENTS - Schedule of Effects on Cash Flow Hedges and Fair Value Hedges on Consolidated Earnings and Comprehensive Income (Details) - CAD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income        
Amount of unrealized gain/(loss) recognized in OCI $ 156 $ (7) $ 182 $ (11)
Amount of (income)/loss reclassified from AOCI to earnings (5) 9 137 23
Foreign exchange contracts        
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income        
Amount of (income)/loss reclassified from AOCI to earnings 0 0 0 (3)
Foreign exchange contracts | Fair value hedges        
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income        
Amount of unrealized gain/(loss) recognized in OCI 0 0 0 12
Interest rate contracts        
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income        
Amount of (income)/loss reclassified from AOCI to earnings (5) 9 137 26
Interest rate contracts | Cash flow hedges        
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income        
Amount of unrealized gain/(loss) recognized in OCI 156 (8) 182 (22)
Commodity contracts | Cash flow hedges        
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income        
Amount of unrealized gain/(loss) recognized in OCI $ 0 $ 1 $ 0 $ (1)