Earnings per Share - Summary of Earnings Per Share (Detail) - CAD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended	6 Months Ended
Apr. 30, 2025	Jan. 31, 2025	Apr. 30, 2024	Apr. 30, 2025	Apr. 30, 2024
Basic earnings per share
Net income attributable to equity shareholders	$ 1,998	$ 2,163	$ 1,739	$ 4,161	$ 3,455
Less: Preferred share dividends and distributions on other equity instruments	78	88	61	166	128
Net income attributable to common shareholders	$ 1,920	$ 2,075	$ 1,678	$ 3,995	$ 3,327
Weighted-average common shares outstanding	938,495	942,039	937,849	940,297	934,779
Basic earnings per share	$ 2.05	$ 2.2	$ 1.79	$ 4.25	$ 3.56
Diluted earnings per share
Net income attributable to common shareholders	$ 1,920	$ 2,075	$ 1,678	$ 3,995	$ 3,327
Weighted-average common shares outstanding	938,495	942,039	937,849	940,297	934,779
Add: Stock options potentially exercisable	4,253	5,306	1,964	4,796	1,201
Weighted-average diluted common shares outstanding	942,748	947,345	939,813	945,093	935,980
Diluted earnings per share	$ 2.04	$ 2.19	$ 1.79	$ 4.23	$ 3.55

The weighted average number of ordinary shares outstanding plus the weighted average number of ordinary shares that would be issued on the conversion of all the dilutive potential ordinary shares into ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]

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Adjustment to profit (loss) for non-participating preference share dividends to calculate profit (loss) attributable to ordinary equity holders of the parent entity. [Refer: Preference shares [member]; Profit (loss)]

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The amount of profit (loss) attributable to ordinary equity holders of the parent entity (the numerator) divided by the weighted average number of ordinary shares outstanding during the period (the denominator).

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The amount of profit (loss) attributable to ordinary equity holders of the parent entity (the numerator), divided by the weighted average number of ordinary shares outstanding during the period (the denominator), both adjusted for the effects of all dilutive potential ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]

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The potential dilutive effect on the weighted average number of ordinary shares that relate to the assumed exercise of the entity's share options.

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The profit (loss) from continuing and discontinued operations attributable to owners of the parent. [Refer: Profit (loss)]

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