v3.24.3
Income taxes - Additional Information (Detail) - CAD ($)
$ in Millions
12 Months Ended
Jun. 20, 2024
Oct. 31, 2024
Oct. 31, 2023
Oct. 31, 2022
Additional details on Income taxes [line items]        
Effective tax rate   18.20% 19.60%  
Deferred tax assets   $ 4,328 $ 3,116 $ 2,120
Unused tax losses   412 417  
Tax credits   18 18  
Amount of temporary differences associated with investments in subsidiaries, branches and associates and interests in joint ventures for which deferred tax liabilities is unrecognized   $ 30,000 22,000  
Description of Canada recovery dividend one time taxation rate and eligibility and maturity       The CRD is a one-time 15% tax for 2022 determined based on the average taxable income above $1 billion for taxation years 2020 and 2021 and payable in equal installments over five years.
Percentage of decrease in effective income tax rate   1.40%    
Budget implementation act of 2024 of Government of Canada [Member]        
Additional details on Income taxes [line items]        
Percentage of global minimum tax rate 15.00%      
Bottom of range [member] | Budget implementation act of 2024 of Government of Canada [Member]        
Additional details on Income taxes [line items]        
Percentage Of Increase In Global Minimum Tax Rate   1.00%    
Top of range [member] | Budget implementation act of 2024 of Government of Canada [Member]        
Additional details on Income taxes [line items]        
Percentage Of Increase In Global Minimum Tax Rate   2.00%    
2009, 2010 and 2011 taxation year [member]        
Additional details on Income taxes [line items]        
Tax examinations and assessments amount   $ 434    
2012 to 2018 taxation year [member]        
Additional details on Income taxes [line items]        
Tax examinations and assessments amount   1,856    
2019 taxation year [member]        
Additional details on Income taxes [line items]        
Tax examinations and assessments amount   277    
Tax loss and tax credit carryforwards [member] | Caribbean, Canadian and Japanese Operations [Member]        
Additional details on Income taxes [line items]        
Deferred tax assets   331 261  
Under 1 year [member]        
Additional details on Income taxes [line items]        
Unused tax losses   0 0  
Tax credits   0 0  
Expire in two to four years [member]        
Additional details on Income taxes [line items]        
Unused tax losses   0 0  
Tax credits   0 0  
Expire after four years [member]        
Additional details on Income taxes [line items]        
Unused tax losses   412 417  
Tax credits   $ 18 $ 18