Derecognition of Financial Assets - Summary of Carrying Amount of Transferred Other Financial Assets Do Not Qualify for Derecognition and Associated Liabilities (Detail) - Other Financial Assets [Member] - CAD ($) $ in Millions	Oct. 31, 2021	Oct. 31, 2020
Disclosure of transferred financial assets that are not derecognised in their entirety [line items]
Carrying value of assets	$ 159,589	$ 175,000
Carrying value of associated liabilities	123,469	137,763
Repurchase agreement [member]
Disclosure of transferred financial assets that are not derecognised in their entirety [line items]
Carrying value of assets	100,083	121,918
Securities lending [member]
Disclosure of transferred financial assets that are not derecognised in their entirety [line items]
Carrying value of assets	$ 59,506	$ 53,082