v3.26.1
Securities - Summary of Credit Risk Exposure by Internal Risk Rating (Detail) - CAD ($)
$ in Millions
Apr. 30, 2026
Oct. 31, 2025
Disclosure of credit risk exposure [line items]    
Amortized cost $ 275,656 $ 241,789
Securities measured at fair value through other comprehensive income [member]    
Disclosure of credit risk exposure [line items]    
Investment grade 273,465 239,375
Non-investment grade 813 790
Impaired 123 134
Carrying amount of securities measured at FVOCI subject to impairment 274,401 240,299
Items not subject to impairment 1,526 1,496
Carrying amount of securities measured at FVOCI 275,927 241,795
Securities measured at amortized cost [member]    
Disclosure of credit risk exposure [line items]    
Investment grade 98,550 99,673
Non-investment grade 1,303 1,267
Amount before allowance for credit losses 99,853 100,940
Allowance for credit losses 17 14
Amortized cost 99,836 100,926
Performing Stage one [member] | Securities measured at fair value through other comprehensive income [member]    
Disclosure of credit risk exposure [line items]    
Investment grade 273,465 239,375
Non-investment grade 809 786
Carrying amount of securities measured at FVOCI subject to impairment 274,274 240,161
Performing Stage one [member] | Securities measured at amortized cost [member]    
Disclosure of credit risk exposure [line items]    
Investment grade 98,550 99,673
Non-investment grade 1,180 1,098
Amount before allowance for credit losses 99,730 100,771
Allowance for credit losses 11 8
Amortized cost 99,719 100,763
Performing Stage two [member] | Securities measured at fair value through other comprehensive income [member]    
Disclosure of credit risk exposure [line items]    
Non-investment grade 4 4
Carrying amount of securities measured at FVOCI subject to impairment 4 4
Performing Stage two [member] | Securities measured at amortized cost [member]    
Disclosure of credit risk exposure [line items]    
Non-investment grade 123 169
Amount before allowance for credit losses 123 169
Allowance for credit losses 6 6
Amortized cost 117 163
Impaired Stage three [member] | Securities measured at fair value through other comprehensive income [member]    
Disclosure of credit risk exposure [line items]    
Impaired 123 134
Carrying amount of securities measured at FVOCI subject to impairment $ 123 $ 134