Stock Compensation - Stock Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 30, 2018	Apr. 30, 2017	Apr. 30, 2018	Apr. 30, 2017
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock compensation expense before taxes	$ 32,965	$ 25,562	$ 65,288	$ 51,396
Income tax benefit	(6,336)	(7,065)	(12,548)	(14,206)
Stock compensation expense after taxes	26,629	18,497	52,740	37,190
Cost of products
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock compensation expense before taxes	3,460	2,813	6,843	5,812
Cost of maintenance and service
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock compensation expense before taxes	1,290	947	2,537	1,808
Research and development expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock compensation expense before taxes	15,150	12,568	30,546	25,452
Sales and marketing expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock compensation expense before taxes	6,875	4,807	13,496	9,936
General and administrative expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock compensation expense before taxes	$ 6,190	$ 4,427	$ 11,866	$ 8,388