v3.26.1
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
Mar. 31, 2026
Mar. 31, 2025
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income    
Amount of unrealized gain/(loss) recognized in OCI $ 3 $ (40)
Amount of loss reclassified from AOCI to earnings 2 20
Foreign exchange contracts    
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income    
Amount of loss reclassified from AOCI to earnings 0 12
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 (6)
Interest rate contracts    
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income    
Amount of loss reclassified from AOCI to earnings 2 8
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 3 (35)
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