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Income Taxes - Additional Information (Detail) $ in Millions, $ in Millions | 1 Months Ended | 3 Months Ended | 6 Months Ended
--- | --- | --- | ---
Jul. 31, 2024 | Apr. 30, 2025 USD ($) | Jan. 31, 2025 CAD ($) | Apr. 30, 2025
Disclosure Of Income Taxes [Line Items] |  |  |  |
Maximum range of estimated consolidated effective tax rate |  | 1.00% |  | 1.00%
2019 Taxation Year [Member] |  |  |  |
Disclosure Of Income Taxes [Line Items] |  |  |  |
Additional income tax by denying the tax deductibility |  |  | $ 1,847 |
2020 Taxation Year [Member] |  |  |  |
Disclosure Of Income Taxes [Line Items] |  |  |  |
Additional Income Taxes Imposed |  | $ 71 |  |
Organization For Economic Cooperation And Development Pillar Two Tax Regime [Member] |  |  |  |
Disclosure Of Income Taxes [Line Items] |  |  |  |
Global minimum tax percentage | 15.00% |  |  |

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