Stock-Based Compensation - Stock Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2019
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense before taxes	$ 56,435	$ 36,914	$ 108,318	$ 75,374
Income tax benefit	(9,808)	(6,214)	(18,826)	(12,688)
Stock-based compensation expense after taxes	46,627	30,700	89,492	62,686
Cost of products
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense before taxes	6,116	4,065	11,696	8,191
Cost of maintenance and service
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense before taxes	2,118	1,522	4,150	2,981
Research and development expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense before taxes	28,893	18,115	55,102	36,419
Sales and marketing expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense before taxes	9,726	7,158	18,620	14,430
General and administrative expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense before taxes	$ 9,582	$ 6,054	$ 18,750	$ 13,353