v3.24.3
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, 2025
Mar. 31, 2025
Dec. 31, 2024
Oct. 31, 2025
$ / Perbarrel
Oct. 31, 2024
CAD ($)
$ / Perbarrel
Oct. 31, 2029
$ / Perbarrel
Oct. 31, 2028
$ / Perbarrel
Oct. 31, 2023
CAD ($)
Statement [Line Items]                
Increase to ACL on performing loans relative to Base Scenario | $         $ 945     $ 868
Oil price (West Texas Intermediate) average price [member] | Downside Scenario [member] | Next Twelve Months [Member]                
Statement [Line Items]                
Average value macroeconomic drivers oil price per barrel       27        
Oil price (West Texas Intermediate) average price [member] | 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] | Base Scenario [member] | Next Two To Five Years [Member]                
Statement [Line Items]                
Average value macroeconomic drivers oil price per barrel           66 67  
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       69 81      
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       89        
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           71    
Canadian unemployment rate [member] | Quarterly Average [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage   7.00% 6.90%          
US unemployment rate [member] | Quarterly Average [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage     4.20%          
Canada GDP growth rate [member] | Above Q4 2024 Levels [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage 1.40%              
U.S. GDP growth rate [member] | Above Q4 2024 Levels [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage 1.30%              
Canadian housing price index [member] | Base Scenario [member] | Next Twelve Months [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage       0.70% 1.60%      
Canadian housing price index [member] | Base Scenario [member] | Next Two To Five Years [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage           3.00% 5.00%  
Canadian housing price index [member] | Upside Scenario [member] | Next Twelve Months [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage       10.90%        
Canadian housing price index [member] | Upside Scenario [member] | Next Two To Five Years [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage           9.60%    
Canadian housing price index [member] | Alternative Downside Scenario [Member] | Next Twelve Months [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage       (30.00%)        
Canadian housing price index [member] | Alternative Downside Scenario [Member] | Next Two To Five Years [Member]                
Statement [Line Items]                
Average value macroeconomic drivers percentage           4.20%