v3.26.3
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 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Net income (loss) per common share – basic        
Net income (loss) $ 2,454 $ 539 $ 5,584 $ 2,776
Weighted-average number of common shares outstanding (millions of shares) 478.8 503.8 482.0 507.3
Net income (loss) per common share (dollars) $ 5.13 $ 1.07 $ 11.59 $ 5.47
Net income (loss) per common share – diluted        
Net income (loss) $ 2,454 $ 539 $ 5,584 $ 2,776
Weighted-average number of common shares outstanding (millions of shares) 478.8 503.8 482.0 507.3
Effect of employee share-based awards (millions of shares) 1.4 1.3 1.3 1.3
Weighted-average number of common shares outstanding, assuming dilution (millions of shares) 480.2 505.1 483.3 508.6
Net income (loss) per common share (dollars) $ 5.11 $ 1.07 $ 11.55 $ 5.46
Dividends per common share – declared (dollars) $ 0.87 $ 0.72 $ 2.61 $ 2.16