v3.22.2.2
Fair value of financial instrument - Summary of Positive and Negative Fair Value Movement of Level 3 Financial Instruments From Using Reasonably Possible Alternative Assumptions (Detail) - Level 3 [member] - CAD ($)
$ in Millions
 12 Months Ended
Oct. 31, 2022
Oct. 31, 2021
Disclosure of fair value measurement of assets and liabilities [line Items]    
Level 3 fair value $ 4,553 $ 3,594
Positive fair value movement from using reasonably possible alternatives 146  
Negative fair value movement from using reasonably possible alternatives (141)  
Level 3 fair value (2,347) (1,548)
Positive fair value movement from using reasonably possible alternatives 64  
Negative fair value movement from using reasonably possible alternatives (66)  
Financial assets at fair value [member]    
Disclosure of fair value measurement of assets and liabilities [line Items]    
Level 3 fair value 4,553 3,594
Positive fair value movement from using reasonably possible alternatives 146 101
Negative fair value movement from using reasonably possible alternatives (141) (98)
U.S. state, municipal and agencies debt [member] | Trading Securities [member]    
Disclosure of fair value measurement of assets and liabilities [line Items]    
Level 3 fair value 4 25
Positive fair value movement from using reasonably possible alternatives   0
Negative fair value movement from using reasonably possible alternatives   (1)
Asset-backed securities [member] | Trading Securities [member]    
Disclosure of fair value measurement of assets and liabilities [line Items]    
Level 3 fair value 2 2
Corporate debt and other debt [member] | Trading Securities [member]    
Disclosure of fair value measurement of assets and liabilities [line Items]    
Level 3 fair value 7 25
Positive fair value movement from using reasonably possible alternatives   1
Negative fair value movement from using reasonably possible alternatives   (1)
Corporate debt and other debt [member] | Investment [member]    
Disclosure of fair value measurement of assets and liabilities [line Items]    
Level 3 fair value 151 152
Positive fair value movement from using reasonably possible alternatives 12 14
Negative fair value movement from using reasonably possible alternatives (10) (13)
Equities [member] | Trading Securities [member]    
Disclosure of fair value measurement of assets and liabilities [line Items]    
Level 3 fair value 1,874 1,530
Positive fair value movement from using reasonably possible alternatives 27 19
Negative fair value movement from using reasonably possible alternatives (23) (16)
Equities [member] | Investment [member]    
Disclosure of fair value measurement of assets and liabilities [line Items]    
Level 3 fair value 397 334
Positive fair value movement from using reasonably possible alternatives 38 33
Negative fair value movement from using reasonably possible alternatives (39) (34)
Loans [member]    
Disclosure of fair value measurement of assets and liabilities [line Items]    
Level 3 fair value 1,692 1,077
Positive fair value movement from using reasonably possible alternatives 60 23
Negative fair value movement from using reasonably possible alternatives (62) (24)
Other assets [member]    
Disclosure of fair value measurement of assets and liabilities [line Items]    
Level 3 fair value 15 0
Mortgage backed securities [Member] | Investment [member]    
Disclosure of fair value measurement of assets and liabilities [line Items]    
Level 3 fair value 28 20
Positive fair value movement from using reasonably possible alternatives 4 4
Negative fair value movement from using reasonably possible alternatives (4) (4)
Derivatives [member]    
Disclosure of fair value measurement of assets and liabilities [line Items]    
Level 3 fair value 383 429
Positive fair value movement from using reasonably possible alternatives 5 7
Negative fair value movement from using reasonably possible alternatives (3) (5)
Deposits [member]    
Disclosure of fair value measurement of assets and liabilities [line Items]    
Level 3 fair value (241) (151)
Positive fair value movement from using reasonably possible alternatives 9 0
Negative fair value movement from using reasonably possible alternatives (9) 0
Derivatives [member]    
Disclosure of fair value measurement of assets and liabilities [line Items]    
Level 3 fair value (2,106) (1,390)
Positive fair value movement from using reasonably possible alternatives 55 30
Negative fair value movement from using reasonably possible alternatives (57) (77)
Other liabilities [member]    
Disclosure of fair value measurement of assets and liabilities [line Items]    
Level 3 fair value   (7)
Financial liabilities at fair value [member]    
Disclosure of fair value measurement of assets and liabilities [line Items]    
Level 3 fair value (2,347) (1,548)
Positive fair value movement from using reasonably possible alternatives 64 30
Negative fair value movement from using reasonably possible alternatives $ (66) $ (77)