v3.26.1
Loans and Allowance for Credit Losses - Summary of Gross Carrying Amount of Loans Measured at Amortized Cost - Small Business (Detail) - Small business [member] - Retail loans [member] - CAD ($)
$ in Millions
Apr. 30, 2026
Oct. 31, 2025
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment $ 17,055 $ 16,797
Low risk [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 11,717 11,223
Medium risk [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 3,188 3,474
High risk [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 1,660 1,681
Not rated [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 10 8
Impaired [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 480 411
Stage one loan [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 13,880 13,445
Stage one loan [member] | Low risk [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 11,169 10,628
Stage one loan [member] | Medium risk [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 2,454 2,550
Stage one loan [member] | High risk [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 247 259
Stage one loan [member] | Not rated [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 10 8
Stage one loan [member] | Impaired [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 0  
Stage two loan [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 2,695 2,941
Stage two loan [member] | Low risk [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 548 595
Stage two loan [member] | Medium risk [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 734 924
Stage two loan [member] | High risk [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 1,413 1,422
Stage two loan [member] | Not rated [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 0  
Stage two loan [member] | Impaired [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 0  
Stage three loan [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 480 411
Stage three loan [member] | Low risk [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 0  
Stage three loan [member] | Medium risk [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 0  
Stage three loan [member] | High risk [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 0  
Stage three loan [member] | Not rated [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment 0  
Stage three loan [member] | Impaired [member]    
Disclosure of credit risk exposure [line items]    
Gross carrying amount of financial assets subject to impairment $ 480 $ 411