v3.24.3
Employee benefits - Pension and other post-employment benefits - Additional Information (Detail) - CAD ($)
shares in Millions, $ in Millions
 12 Months Ended
Oct. 31, 2024
Oct. 31, 2023
Disclosure of employee benefits [line items]    
Plan assets, fair value of our debt securities $ 74 $ 62
Dividends received on our common shares held in plan assets $ 2 $ 3
Common shares [member]    
Disclosure of employee benefits [line items]    
Number of our common shares included in plan assets 0.4 0.3
Plan assets, fair value of our common shares $ 66 $ 37
Defined benefit pension plans [member] | Canada [member]    
Disclosure of employee benefits [line items]    
Remeasurement gains (losses) recorded in OCI 818 (440)
Defined benefit pension plans [member] | Foreign countries [member]    
Disclosure of employee benefits [line items]    
Remeasurement gains (losses) recorded in OCI 5 (44)
Defined benefit and contribution pension plans [member]    
Disclosure of employee benefits [line items]    
Contributions to pension plans (defined benefit and defined contribution plans) and other post-employment benefit plans 455 346
Estimated contributions to pension plans and other post-employment benefit plans 508  
Defined benefit and contribution pension plans [member] | Canada [member]    
Disclosure of employee benefits [line items]    
Service costs for pension plans 186 193
Net interest expense (income) for pension plans (5) (5)
Defined benefit and contribution pension plans [member] | Foreign countries [member]    
Disclosure of employee benefits [line items]    
Service costs for pension plans 2 2
Net interest expense (income) for pension plans (145) (157)
Other post employment benefit plan [member]    
Disclosure of employee benefits [line items]    
Contributions to pension plans (defined benefit and defined contribution plans) and other post-employment benefit plans 91 $ 80
Estimated contributions to pension plans and other post-employment benefit plans $ 93