Loans, Impaired Loans and Allowance for Credit Losses - Summary of Purchased Credit Impaired Loans (Detail) - CAD ($) $ in Millions |
Jul. 31, 2026 |
Apr. 30, 2026 |
Oct. 31, 2025 |
Jul. 31, 2025 |
Oct. 31, 2024 |
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|---|---|---|---|---|---|---|---|
| Disclosure of detailed information about financial instruments [line items] | |||||||
| Allowance | $ (7,532) | $ (7,639) | $ (7,371) | $ (6,723) | |||
| Loans acquired in business combination [member] | |||||||
| Disclosure of detailed information about financial instruments [line items] | |||||||
| Unpaid principal balance | [1] | 206 | $ 204 | 224 | |||
| Credit-related fair value adjustments | (19) | (19) | (24) | ||||
| Carrying value | 187 | 185 | 200 | ||||
| Carrying value net of related allowance | 187 | 185 | 199 | ||||
| Loans acquired in business combination [member] | Stage 3 [member] | |||||||
| Disclosure of detailed information about financial instruments [line items] | |||||||
| Allowance | $ 0 | $ 0 | $ (1) | ||||
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