v3.25.4
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
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Net income (loss) per common share – basic      
Net income (loss) $ 3,268 $ 4,790 $ 4,889
Weighted-average number of common shares outstanding (millions of shares) 502.8 529.4 574.8
Net income (loss) per common share (dollars) $ 6.50 $ 9.05 $ 8.51
Net income (loss) per common share – diluted      
Net income (loss) $ 3,268 $ 4,790 $ 4,889
Weighted-average number of common shares outstanding (millions of shares) 502.8 529.4 574.8
Effect of employee share-based awards (millions of shares) 1.2 1.2 1.1
Weighted-average number of common shares outstanding, assuming dilution (millions of shares) 504.0 530.6 575.9
Net income (loss) per common share (dollars) $ 6.48 $ 9.03 $ 8.49
Dividends per common share – declared (dollars) $ 2.88 $ 2.40 $ 1.94