v3.26.1
Securities - Summary of Allowance for Credit Losses - Securities at Amortized Cost (Detail) - Debt securities at amortized cost [member] - CAD ($)
$ in Millions
3 Months Ended 6 Months Ended
Apr. 30, 2026
Apr. 30, 2025
Apr. 30, 2026
Apr. 30, 2025
Disclosure of credit risk exposure [line items]        
Balance at beginning of period $ 14 $ 14 $ 14 $ 14
Provision for credit losses        
Purchases 5 1 6 2
Changes in risk, parameters and exposures (2) (1) (3) (2)
Balance at end of period 17 14 17 14
Performing Stage one [member]        
Disclosure of credit risk exposure [line items]        
Balance at beginning of period 8 6 8 6
Provision for credit losses        
Purchases 5 1 6 2
Changes in risk, parameters and exposures (2)   (2) (1)
Exchange rate and other   (1) (1) (1)
Balance at end of period 11 6 11 6
Performing Stage two [member]        
Disclosure of credit risk exposure [line items]        
Balance at beginning of period 6 8 6 8
Provision for credit losses        
Changes in risk, parameters and exposures   (1) (1) (1)
Exchange rate and other   1 1 1
Balance at end of period $ 6 $ 8 $ 6 $ 8