Deposits and Subordinated Debt - Additional Information (Details) - CAD ($) $ in Millions |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Dec. 15, 2025 |
Apr. 30, 2026 |
Apr. 30, 2025 |
Apr. 30, 2026 |
Apr. 30, 2025 |
|
| Disclosure Of Deposits [Line Items] | |||||
| Repayments of subordinated liabilities | $ 0 | $ 0 | $ 25 | $ 0 | |
| Debentures Series 20 | |||||
| Disclosure Of Deposits [Line Items] | |||||
| Repayments of subordinated liabilities | $ 25 | ||||
| Debentures Series 20 | Subordinated Debt | |||||
| Disclosure Of Deposits [Line Items] | |||||
| Notional amount | 150 | ||||
| Periodic payment, amount | $ 25 | ||||
| Periodic payment, period | 3 years | ||||