v3.22.2.2
Goodwill and other intangible assets - Additional Information (Detail) - CAD ($)
$ in Millions
Aug. 01, 2022
Aug. 01, 2020
Aug. 01, 2021
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Period of discounted cash flow method for calculating value in use   five-year  
Caribbean Banking [member]      
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Description of valuation techniques used to measure fair value less costs of disposal   FVLCD using a discounted cash flow method that projects future cash flows over a 5-year period.  
Description of level of fair value hierarchy within which fair value measurement is categorised   level 3  
Reduction in future cash flows to determine sensitivity of current estimate of fair value less costs of disposal 10.00%    
Percentage of unit's recoverable amount exceeds its carrying amount 109.00%   123.00%
Pretax discount rate for future cash flows 12.60%   10.90%
A 50 bps change in the discount rate would decrease in recoverable amount of goodwill $ 267    
A 50 bps change in the terminal growth rate would Increase in recoverable amount of goodwill 231    
A 50 bps change in the terminal growth rate would decrease in recoverable amount of goodwill 203    
Decrease in recoverable amount of goodwill due to percentage reduction in cash flow forecast $ 440    
Percentage of reduction in future cash flows holding other individual factors constant 8.00%