v3.22.2.2
Income taxes - Additional Information (Detail) - CAD ($)
$ in Millions
12 Months Ended
Apr. 07, 2022
Oct. 31, 2022
Oct. 31, 2021
Oct. 31, 2020
Additional details on Income taxes [line items]        
Effective tax rate   21.40% 22.20%  
Deferred tax assets   $ 1,472 $ 2,011 $ 2,579
Unused tax losses   429 384  
Tax credits   130 207  
Amount of temporary differences associated with investments in subsidiaries, branches and associates and interests in joint ventures for which deferred tax liabilities is unrecognized   26,000 20,000  
CRD effect on net income   1,000    
CRD effect on other comprehensive income   100    
Permanent increase in corporate income tax rate on taxable income above 100 million 1.50%      
2009, 2010 and 2011 taxation year [member]        
Additional details on Income taxes [line items]        
Tax examinations and assessments amount   434    
2012 to 2016 taxation year [member]        
Additional details on Income taxes [line items]        
Tax examinations and assessments amount   1,391    
2017 taxation year [member]        
Additional details on Income taxes [line items]        
Tax examinations and assessments amount   237    
2022 taxation year [member]        
Additional details on Income taxes [line items]        
One time income tax rate percentage 15.00%      
Threshold limit of taxable income beyond which one time time tax is applicable $ 1,000      
Duration over which the one time tax shall be paid 5 years      
Tax loss and tax credit carryforwards [member] | Caribbean, Canadian and Japanese Operations [Member]        
Additional details on Income taxes [line items]        
Deferred tax assets   322 242  
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 2  
Tax credits   93 115  
Expire after four years [member]        
Additional details on Income taxes [line items]        
Unused tax losses   429 382  
Tax credits   $ 37 $ 92