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 9 Months Ended
Jul. 31, 2026
Jul. 31, 2025
Jul. 31, 2026
Jul. 31, 2025
Disclosure of credit risk exposure [line items]        
Balance at beginning of period $ 17 $ 14 $ 14 $ 14
Provision for credit losses        
Purchases 3 3 9 5
Changes in risk, parameters and exposures (3) (3) (6) (5)
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 11 6 8 6
Provision for credit losses        
Purchases 3 3 9 5
Changes in risk, parameters and exposures (1) (3) (3) (4)
Exchange rate and other (1) 1 (2)  
Balance at end of period 12 7 12 7
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 (2) 0 (3) (1)
Exchange rate and other 1 (1) 2  
Balance at end of period $ 5 $ 7 $ 5 $ 7