Net Income per Share - Reconciliation of Weighted Average Common Shares Used to Calculate Basic Net Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2019
Numerator:
Net income (loss)		$ 109,920	$ 118,210	$ 213,981	$ 271,724
Denominator:
Weighted-average common shares for basic net income per share (shares)		150,597	149,712	150,421	149,500
Dilutive effect of potential common shares from equity-based compensation (shares)		3,782	4,192	4,050	3,883
Weighted-average common shares for diluted net income per share (shares)		154,379	153,904	154,471	153,383
Net income per share:
Basic (in USD per share)		$ 0.73	$ 0.79	$ 1.42	$ 1.82
Diluted (in USD per share)		$ 0.71	$ 0.77	$ 1.39	$ 1.77
Anti-dilutive employee stock-based awards excluded (shares)	[1]	743	49	579	1,538

[1] These stock options and unvested restricted stock units were anti-dilutive for the respective periods and are excluded in calculating diluted net income per share. While such awards were anti-dilutive for the respective periods, they could be dilutive in the future.