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		9 Months Ended
		Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019
Numerator:
Net income		$ 252,911	$ 99,929	$ 466,892	$ 371,653
Denominator:
Weighted-average common shares for basic net income per share (shares)		151,352	150,123	150,731	149,708
Dilutive effect of potential common shares from equity-based compensation (shares)		4,621	4,477	4,343	4,151
Weighted-average common shares for diluted net income per share (shares)		155,973	154,600	155,074	153,859
Net income per share:
Basic (in USD per share)		$ 1.67	$ 0.67	$ 3.10	$ 2.48
Diluted (in USD per share)		$ 1.62	$ 0.65	$ 3.01	$ 2.42
Anti-dilutive employee stock-based awards excluded (shares)	[1]	3	152	610	798

[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.