v3.26.1
Equity (Summary of Classes of Share Capital - Treasury Shares) (Details) - CAD ($)
shares in Thousands, $ in Millions
 3 Months Ended 6 Months Ended
Apr. 30, 2026
Apr. 30, 2025
Apr. 30, 2026
Apr. 30, 2025
Disclosure of classes of share capital [line items]        
Balance at beginning of period     $ 127,827  
Balance at end of period $ 124,318 $ 126,091 $ 124,318 $ 126,091
Common shares [member] | Treasury shares [member]        
Disclosure of classes of share capital [line items]        
Beginning balance, Number of shares 41 458 0 213
Purchase of shares, Number of shares 21,888 34,066 48,916 78,941
Sale of shares, Number of shares (21,560) (34,211) (48,547) (78,841)
Ending balance, Number of shares 369 313 369 313
Balance at beginning of period $ (5) $ (38) $ 0 $ (17)
Purchase of shares, Amount (2,899) (2,880) (6,213) (6,384)
Sale of shares, Amount 2,844 2,892 6,153 6,375
Balance at end of period (60) (26) (60) (26)
Preferred shares and other equity instruments [member]        
Disclosure of classes of share capital [line items]        
Balance at end of period $ 11,625 $ 11,138 $ 11,625 $ 11,138
Preferred shares and other equity instruments [member] | Treasury shares [member]        
Disclosure of classes of share capital [line items]        
Beginning balance, Number of shares 11 549 29 163
Purchase of shares, Number of shares 347 989 569 3,442
Sale of shares, Number of shares (333) (1,397) (573) (3,464)
Ending balance, Number of shares 25 141 25 141
Balance at beginning of period $ (11) $ (51) $ (4) $ (18)
Purchase of shares, Amount (353) (267) (515) (1,387)
Sale of shares, Amount 350 290 505 1,377
Balance at end of period $ (14) $ (28) $ (14) $ (28)