Loans, Impaired Loans and Allowance for Credit Losses - Schedule of Loans at Amortized Cost (Detail) - CAD ($) $ in Millions	Apr. 30, 2022	Jan. 31, 2022	Oct. 31, 2021
Gross carrying amount [member]
Disclosure of fair value financial assets amortised cost [line Items]
Financial assets	$ 694,996	$ 672,830	$ 642,612
Gross carrying amount [member] | Residential mortgages [member]
Disclosure of fair value financial assets amortised cost [line Items]
Financial assets	337,714	330,991	319,678
Gross carrying amount [member] | Loans to consumers [member]
Disclosure of fair value financial assets amortised cost [line Items]
Financial assets	94,437	92,622	91,540
Gross carrying amount [member] | Credit Card [member]
Disclosure of fair value financial assets amortised cost [line Items]
Financial assets	13,622	13,145	12,450
Gross carrying amount [member] | Business and government [member]
Disclosure of fair value financial assets amortised cost [line Items]
Financial assets	249,223	236,072	218,944
Net Carrying Amount [member]
Disclosure of fair value financial assets amortised cost [line Items]
Financial assets	689,702	667,338	636,986
Net Carrying Amount [member] | Residential mortgages [member]
Disclosure of fair value financial assets amortised cost [line Items]
Financial assets	336,880	330,156	318,876
Net Carrying Amount [member] | Loans to consumers [member]
Disclosure of fair value financial assets amortised cost [line Items]
Financial assets	92,266	90,373	89,199
Net Carrying Amount [member] | Credit Card [member]
Disclosure of fair value financial assets amortised cost [line Items]
Financial assets	12,515	11,980	11,239
Net Carrying Amount [member] | Business and government [member]
Disclosure of fair value financial assets amortised cost [line Items]
Financial assets	248,041	234,829	217,672
Financial assets individually assessed for credit losses [member]
Disclosure of fair value financial assets amortised cost [line Items]
Financial assets	5,294	5,492	5,626
Financial assets individually assessed for credit losses [member] | Residential mortgages [member]
Disclosure of fair value financial assets amortised cost [line Items]
Financial assets	834	835	802
Financial assets individually assessed for credit losses [member] | Loans to consumers [member]
Disclosure of fair value financial assets amortised cost [line Items]
Financial assets	2,171	2,249	2,341
Financial assets individually assessed for credit losses [member] | Credit Card [member]
Disclosure of fair value financial assets amortised cost [line Items]
Financial assets	1,107	1,165	1,211
Financial assets individually assessed for credit losses [member] | Business and government [member]
Disclosure of fair value financial assets amortised cost [line Items]
Financial assets	$ 1,182	$ 1,243	$ 1,272