Stock-based compensation - Fair Value Assumptions of Stock Options (Detail) - Stock Options	3 Months Ended
	Jan. 31, 2025	Jan. 31, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility, minimum	30.30%	30.50%
Expected volatility, maximum	31.20%	31.70%
Risk-free interest rate, minimum	4.43%	4.22%
Risk-free interest rate, maximum	4.48%	4.26%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	1.51%	1.15%
Expected life of the option (in years)	5 years	5 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	1.51%	1.15%
Expected life of the option (in years)	6 years 3 months 18 days	6 years 2 months 12 days