v3.26.1
Employee Benefits - Summary of Financial Information related to Principal Plans (Detail) - CAD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Jul. 31, 2026
Apr. 30, 2026
Jul. 31, 2025
Jul. 31, 2026
Jul. 31, 2025
Disclosure of defined benefit plans [line items]          
Actuarial gains (losses) on employee benefit plans in other comprehensive income $ 443 $ 64 $ 270 $ 775 $ 275
Pension plans [member]          
Disclosure of defined benefit plans [line items]          
Defined benefit service cost [1] 60 60 70 180 214
Interest on net defined benefit (asset) liability [1] (6) (6) (2) (18) (9)
Other [1] 3 3 3 9 9
Defined benefit expense [1] 57 57 71 171 214
Defined contribution expense [1] 58 58 52 172 154
Actuarial gains (losses) on employee benefit plans in other comprehensive income [1],[2] 372 65 267 712 294
Other benefit plans [member]          
Disclosure of defined benefit plans [line items]          
Defined benefit service cost [1] 4 5 (57) [3] 14 (45) [3]
Interest on net defined benefit (asset) liability [1] 16 16 16 48 46
Other [1] (5) (1) 1 (6) 1
Defined benefit expense [1] 15 20 (40) 56 2
Defined contribution expense [1]         1
Actuarial gains (losses) on employee benefit plans in other comprehensive income [1],[2] $ 71 $ (1) $ 3 $ 63 $ (19)
[1] Other plans operated by certain subsidiaries of the Bank are not considered material and are not included in this note.
[2] Changes in discount rates and return on plan assets are reviewed and updated on a quarterly basis. In the absence of legislated changes, all other assumptions are updated annually.
[3] Includes benefit related to certain post-retirement plan amendments.