v3.22.2.2
Loans and Allowance for Credit Losses, Key Inputs and Assumptions - Additional Information (Detail)
$ in Millions
 3 Months Ended 12 Months Ended 48 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Sep. 30, 2023
$ / Perbarrel
Sep. 30, 2022
$ / Perbarrel
Sep. 30, 2027
$ / Perbarrel
Sep. 30, 2026
$ / Perbarrel
Oct. 31, 2022
CAD ($)
Oct. 31, 2021
CAD ($)
Statement [Line Items]                
Increase to ACL on performing loans relative to Base Scenario | $             $ 738 $ 726
Oil price (West Texas Intermediate) average price [member] | Base Scenario [member] | Next Two To Five Years [Member]                
Statement [Line Items]                
Average value macroeconomic drivers oil price per barrel         72 56    
Oil price (West Texas Intermediate) average price [member] | Base Scenario [member] | Next Twelve Months [Member]                
Statement [Line Items]                
Average value macroeconomic drivers oil price per barrel     88 71        
Oil price (West Texas Intermediate) average price [member] | Upside Scenario [member] | Next Twelve Months [Member]                
Statement [Line Items]                
Average value macroeconomic drivers oil price per barrel     114          
Oil price (West Texas Intermediate) average price [member] | Upside Scenario [member] | Next Two To Five Years [Member]                
Statement [Line Items]                
Average value macroeconomic drivers oil price per barrel         77      
Oil price (West Texas Intermediate) average price [member] | Alternative Downside Scenario [Member] | Next Two To Five Years [Member]                
Statement [Line Items]                
Average value macroeconomic drivers oil price per barrel         42      
Oil price (West Texas Intermediate) average price [member] | Alternative Downside Scenario [Member] | Next Twelve Months [Member]                
Statement [Line Items]                
Average value macroeconomic drivers oil price per barrel     29          
Canadian unemployment rate [member] | Quarterly Average [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage 6.80% 5.60%            
US unemployment rate [member] | Quarterly Average [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage 5.10% 3.90%            
Canada GDP growth rate [member] | Above Pre Shock Level [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage 0.20%              
U.S. GDP growth rate [member] | Above Pre Shock Level [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage 0.40%              
Canadian housing price index growth rate [member] | Base Scenario [member] | Next Twelve Months [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage     (1.00%) 0.10%        
Canadian housing price index growth rate [member] | Base Scenario [member] | Next Two To Five Years [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage         5.20% 4.10%    
Canadian housing price index growth rate [member] | Upside Scenario [member] | Next Twelve Months [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage     10.90%          
Canadian housing price index growth rate [member] | Upside Scenario [member] | Next Two To Five Years [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage         9.50%      
Canadian housing price index growth rate [member] | Alternative Downside Scenario [Member] | Next Twelve Months [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage     (30.00%)          
Canadian housing price index growth rate [member] | Alternative Downside Scenario [Member] | Next Two To Five Years [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage         4.20%