v3.26.1
Other comprehensive income (loss) information - Changes in Accumulated Other Comprehensive Income (Loss) (Detail) - CAD ($)
$ in Millions
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
At beginning of period $ 22,254  
At end of period 22,748 $ 24,411
Accumulated Defined Benefit Plans Adjustment Attributable to Parent    
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
At beginning of period (14) (214)
Current period change excluding amounts reclassified from accumulated other comprehensive income (28) 12
Amounts reclassified from accumulated other comprehensive income 3 5
At end of period $ (39) $ (197)