v3.22.2.2
Securities - Summary of Allowance for Credit Losses - Securities at FVOCI (Detail) - Debt securities at fair value through other comprehensive income [member] - CAD ($)
$ in Millions
12 Months Ended
Oct. 31, 2022
Oct. 31, 2021
Disclosure of financial assets [line items]    
Balance at beginning of period $ (9) $ 8
Provision for credit losses    
Model changes   (4)
Purchases 3 8
Sales and maturities (1) (11)
Changes in risk, parameters and exposures (11) (10)
Exchange rate and other (1)  
Balance at end of period (19) (9)
Performing Stage one [member]    
Disclosure of financial assets [line items]    
Balance at beginning of period 2 12
Provision for credit losses    
Model changes   (4)
Transfers to Stage 1 1 1
Purchases 3 8
Sales and maturities (1) (10)
Changes in risk, parameters and exposures (2) (4)
Exchange rate and other   (1)
Balance at end of period 3 2
Performing Stage two [member]    
Disclosure of financial assets [line items]    
Balance at beginning of period 1  
Provision for credit losses    
Transfers to Stage 1 (1) (1)
Sales and maturities   (1)
Changes in risk, parameters and exposures 1 3
Balance at end of period 1 1
Impaired Stage three [member]    
Disclosure of financial assets [line items]    
Balance at beginning of period (12) (4)
Provision for credit losses    
Changes in risk, parameters and exposures (10) (9)
Exchange rate and other (1) 1
Balance at end of period $ (23) $ (12)