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IFRS 7 Disclosure - Market Risk - Summary Total Trading Value at Risk (VaR) (Detail) - CAD ($) $ in Millions | Oct. 31, 2025 | Oct. 31, 2024
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Commodity price risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | $ 8.2 | $ 2.1
Equity price risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 12.8 | 24.0
Foreign exchange risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 0.8 | 1.0
Interest rate risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 30.0 | 23.0
Risk diversification effect [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | (25.9) | (17.6)
Market risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 25.9 | 32.5
Average [Member] | Commodity price risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 8.0 | 3.8
Average [Member] | Equity price risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 20.1 | 16.1
Average [Member] | Foreign exchange risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 1.8 | 1.2
Average [Member] | Interest rate risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 28.2 | 30.8
Average [Member] | Risk diversification effect [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | (21.1) | (19.7)
Average [Member] | Market risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 37.0 | 32.2
Top of range [member] | Commodity price risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 16.1 | 5.4
Top of range [member] | Equity price risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 35.7 | 24.0
Top of range [member] | Foreign exchange risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 5.1 | 2.9
Top of range [member] | Interest rate risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 41.9 | 44.7
Top of range [member] | Market risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 48.1 | 45.5
Bottom of range [member] | Commodity price risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 2.0 | 2.0
Bottom of range [member] | Equity price risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 11.7 | 8.1
Bottom of range [member] | Foreign exchange risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 0.8 | 0.4
Bottom of range [member] | Interest rate risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | 21.4 | 22.1
Bottom of range [member] | Market risk [member] |  |
Market Risk [Line Items] |  |
Market risk VaR | $ 25.9 | $ 23.1

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