v3.26.1
Equity - Summary of Classes of Preferred and Common Shares Outstanding (Details) - CAD ($)
$ / shares in Units, $ in Millions
 3 Months Ended 6 Months Ended 9 Months Ended
Nov. 12, 2025
Nov. 01, 2025
Jul. 31, 2026
Apr. 30, 2026
Jan. 31, 2026
Jul. 31, 2025
Apr. 30, 2025
Jul. 31, 2026
Jul. 31, 2025
Oct. 31, 2025
Oct. 31, 2024
Aug. 25, 2024
Disclosure of classes of share capital [line items]                        
Amount     $ 86,573     $ 86,765   $ 86,573 $ 86,765 $ 88,100    
Common stock conversion price     $ 5.00         $ 5.00        
Burgundy Asset Management Ltd.                        
Disclosure of classes of share capital [line items]                        
Number of shares issued in an acquisition (in shares)   2,723,726                    
Value of shares issued in an acquisition   $ 481                    
Treasury shares                        
Disclosure of classes of share capital [line items]                        
Number of shares (in shares)     0         0   0    
4.800% Additional Tier 1 Capital Notes (AT1 Notes)                        
Disclosure of classes of share capital [line items]                        
Borrowings, interest rate                       4.80%
Borrowings, adjustment to interest rate basis                       6.709%
Preferred Shares and Other Equity Instruments                        
Disclosure of classes of share capital [line items]                        
Amount     $ 7,706 $ 7,706   9,156 $ 7,787 $ 7,706 9,156 $ 8,956 $ 8,087  
Preferred Shares – Classified as Equity                        
Disclosure of classes of share capital [line items]                        
Amount     $ 1,550         $ 1,550   $ 1,550    
Class B – Series 44                        
Disclosure of classes of share capital [line items]                        
Number of shares (in shares)     16,000,000         16,000,000   16,000,000    
Amount     $ 400         $ 400   $ 400    
Dividends declared per share (in canadian dollars per share)         $ 1.70     $ 1.28        
Class B – Series 50                        
Disclosure of classes of share capital [line items]                        
Number of shares (in shares)     500,000         500,000   500,000    
Amount     $ 500         $ 500   $ 500    
Dividends declared per share (in canadian dollars per share)         73.73     $ 36.87        
Class B – Series 52                        
Disclosure of classes of share capital [line items]                        
Number of shares (in shares)     650,000         650,000   650,000    
Amount     $ 650         $ 650   $ 650    
Dividends declared per share (in canadian dollars per share)         70.57     $ 35.29        
Other Equity Instruments                        
Disclosure of classes of share capital [line items]                        
Amount     6,156         $ 6,156   7,406    
Other Equity Instruments | 4.800% Additional Tier 1 Capital Notes (AT1 Notes)                        
Disclosure of classes of share capital [line items]                        
Amount     $ 658         $ 658   658    
Borrowings, interest rate     4.80%         4.80%        
Other Equity Instruments | 4.300% Limited Recourse Capital Notes, Series 1 (LRCNs, Series 1)                        
Disclosure of classes of share capital [line items]                        
Amount     $ 0         $ 0   1,250    
Borrowings, interest rate     4.30%         4.30%        
Redemption amount $ 1,250                      
Compound instrument interest rate 4.30%                      
Other Equity Instruments | 5.625% Limited Recourse Capital Notes, Series 2 (LRCNs, Series 2)                        
Disclosure of classes of share capital [line items]                        
Amount     $ 750         $ 750   750    
Borrowings, interest rate     5.625%         5.625%        
Other Equity Instruments | 7.325% Limited Recourse Capital Notes, Series 3 (LRCNs, Series 3)                        
Disclosure of classes of share capital [line items]                        
Amount     $ 1,000         $ 1,000   1,000    
Borrowings, interest rate     7.325%         7.325%        
Other Equity Instruments | 7.700% Limited Recourse Capital Notes, Series 4 (LRCNs, Series 4)                        
Disclosure of classes of share capital [line items]                        
Amount     $ 1,356         $ 1,356   1,356    
Borrowings, interest rate     7.70%         7.70%        
Other Equity Instruments | 7.300% Limited Recourse Capital Notes, Series 5 (LRCNs, Series 5)                        
Disclosure of classes of share capital [line items]                        
Amount     $ 1,023         $ 1,023   1,023    
Borrowings, interest rate     7.30%         7.30%        
Other Equity Instruments | 6.875% Limited Recourse Capital Notes, Series 6 (LRCNs, Series 6)                        
Disclosure of classes of share capital [line items]                        
Amount     $ 1,369         $ 1,369   $ 1,369    
Borrowings, interest rate     6.875%         6.875%        
Common Shares                        
Disclosure of classes of share capital [line items]                        
Number of shares (in shares)     697,146,398         697,146,398   708,905,679    
Amount     $ 23,473 $ 23,537   $ 23,554 $ 23,730 $ 23,473 $ 23,554 $ 23,359 $ 23,921  
Dividends declared per share (in canadian dollars per share)     $ 1.71 $ 1.67 $ 6.44 $ 1.63   $ 5.05 $ 4.81      
Common shares convertible from stock option plan (in shares)             5,699,134 5,169,041        
Number of share options exercisable in share-based payment arrangement (in shares)     2,020,746         2,020,746   2,245,942    
Value of shares issued in an acquisition     $ 0     $ 0   $ 481 $ 0      
Common Shares | Stock Option Plan                        
Disclosure of classes of share capital [line items]                        
Common shares issued under stock option plan (in shares)     507,279     289,748   1,294,493 975,467      
Class B - Series 48                        
Disclosure of classes of share capital [line items]                        
Preferred shares redeemed $ 1,250