v3.22.2.2
Employee benefits - Pension and other post-employment benefits - Summary of Composition of Pension and Other Post-employment Benefit Expense (Detail) - CAD ($)
$ in Millions
 12 Months Ended
Oct. 31, 2022
Oct. 31, 2021
Disclosure of pension and other post employment plan [Line Items]    
Total pension and other post-employment benefit expense $ 16,528 $ 16,539
Defined benefit pension plans [member] | Pension Expense [Member]    
Disclosure of pension and other post employment plan [Line Items]    
Current service costs 308 359
Past service costs (1)  
Gains and losses on settlements (3) 2
Net interest expense (income) (84) 7
Administrative expense 14 13
Defined benefit pension expense 234 381
Defined contribution pension plans [Member] | Pension Expense [Member]    
Disclosure of pension and other post employment plan [Line Items]    
Defined contribution pension expense 250 235
Defined benefit and contribution pension plans [member] | Pension Expense [Member]    
Disclosure of pension and other post employment plan [Line Items]    
Total pension and other post-employment benefit expense 484 616
Other post employment benefit [member] | Other post employment benefit expense [Member]    
Disclosure of pension and other post employment plan [Line Items]    
Current service costs 42 46
Past service costs 2 (1)
Net interest expense (income) 63 57
Remeasurements of other long-term benefits (26) (12)
Defined benefit pension expense 81 90
Total pension and other post-employment benefit expense $ 81 $ 90