Insurance - Summary of Yield Curve Used to Discount Cash Flows that do not Vary Based on Underlying Items (Detail)	Jan. 31, 2025	Oct. 31, 2024
1 year [member]
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]
Yield used to discount cash flows that do not vary based on returns on underlying items	3.58%	4.16%
3 years [member]
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]
Yield used to discount cash flows that do not vary based on returns on underlying items	3.78%	4.17%
5 years [member]
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]
Yield used to discount cash flows that do not vary based on returns on underlying items	4.04%	4.35%
10 years [member]
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]
Yield used to discount cash flows that do not vary based on returns on underlying items	4.63%	4.82%
20 years [member]
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]
Yield used to discount cash flows that do not vary based on returns on underlying items	5.04%	5.15%
30 years [member]
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]
Yield used to discount cash flows that do not vary based on returns on underlying items	4.89%	4.98%
Ultimate [member]
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]
Yield used to discount cash flows that do not vary based on returns on underlying items	5.00%	5.00%