v3.26.1
Common shares - Calculation of basic and diluted earnings per common share and the dividend declared by the company on its outstanding common shares (Detail) - CAD ($)
$ / shares in Units, shares in Millions, $ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Net income (loss) per common share – basic        
Net income (loss) $ 2,190 $ 949 $ 3,130 $ 2,237
Weighted-average number of common shares outstanding (millions of shares) 483.6 509.0 483.6 509.0
Net income (loss) per common share (dollars) $ 4.53 $ 1.86 $ 6.47 $ 4.39
Net income (loss) per common share – diluted        
Net income (loss) $ 2,190 $ 949 $ 3,130 $ 2,237
Weighted-average number of common shares outstanding (millions of shares) 483.6 509.0 483.6 509.0
Effect of employee share-based awards (millions of shares) 1.3 1.3 1.3 1.2
Weighted-average number of common shares outstanding, assuming dilution (millions of shares) 484.9 510.3 484.9 510.2
Net income (loss) per common share (dollars) $ 4.52 $ 1.86 $ 6.46 $ 4.38
Dividends per common share – declared (dollars) $ 0.87 $ 0.72 $ 1.74 $ 1.44