v3.26.1
Capital and financing transactions - Schedule of capital and financing transactions (Detail) - CAD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Jul. 31, 2026
Jul. 31, 2025
Jul. 31, 2026
Jul. 31, 2025
Disclosure of objectives, policies and processes for managing capital [line items]        
Beginning Balance $ 88,582   $ 88,587 $ 84,076
Issued in relation to share-based payments, net [1]     $ 9 13
Repurchased for cancellation under the Normal Course Issuer Bid (shares) 8,600,000   19,900,000  
Repurchased for cancellation under the Normal Course Issuer Bid $ (1,031)   $ (2,182)  
Ending Balance $ 90,622 $ 85,483 $ 90,622 $ 85,483
Common shares [member]        
Disclosure of objectives, policies and processes for managing capital [line items]        
Outstanding at beginning of period 1,226,787,360 1,245,549,363 1,236,305,738 1,244,435,686
Beginning Balance $ 22,002 $ 22,138 $ 22,067 $ 22,054
Issued in relation to share-based payments, net (shares) 672,594 138,392 2,414,326 1,252,069
Issued in relation to share-based payments, net $ 56 $ 10 $ 196 $ 94
Repurchased for cancellation under the Normal Course Issuer Bid (shares) (8,648,300) (3,227,456) (19,908,410) (3,227,456)
Repurchased for cancellation under the Normal Course Issuer Bid $ (159) $ (59) $ (364) $ (59)
Outstanding at end of period 1,218,811,654 1,242,460,299 1,218,811,654 1,242,460,299
Ending Balance $ 21,899 $ 22,089 $ 21,899 $ 22,089
[1] Represents amounts on account of share-based payments (refer to Note 12).