Loans and Allowance for Credit Losses - Disclosure of Loans Past Due But Not Impaired (Detail) - CAD ($) $ in Millions	Apr. 30, 2026	Oct. 31, 2025
Disclosure of loans that are either past due or impaired [line items]
Loans past due but not impaired	$ 3,695	$ 4,107
Retail [member]
Disclosure of loans that are either past due or impaired [line items]
Loans past due but not impaired	2,837	2,957
Wholesale [member]
Disclosure of loans that are either past due or impaired [line items]
Loans past due but not impaired	858	1,150
30 to 89 days [member]
Disclosure of loans that are either past due or impaired [line items]
Loans past due but not impaired	3,337	3,777
30 to 89 days [member] \| Retail [member]
Disclosure of loans that are either past due or impaired [line items]
Loans past due but not impaired	2,479	2,634
30 to 89 days [member] \| Wholesale [member]
Disclosure of loans that are either past due or impaired [line items]
Loans past due but not impaired	858	1,143
90 Days and Greater [member]
Disclosure of loans that are either past due or impaired [line items]
Loans past due but not impaired	358	330
90 Days and Greater [member] \| Retail [member]
Disclosure of loans that are either past due or impaired [line items]
Loans past due but not impaired	358	323
90 Days and Greater [member] \| Wholesale [member]
Disclosure of loans that are either past due or impaired [line items]
Loans past due but not impaired	$ 0	$ 7