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, 2016	Apr. 30, 2015	Apr. 30, 2016	Apr. 30, 2015
Earnings Per Share [Abstract]
Net income		$ 69,376	$ 55,596	$ 129,411	$ 120,785
Weighted-average common shares for basic net income per share (shares)		152,250	154,515	152,609	154,486
Dilutive effect of potential common shares from equity-based compensation (shares)		2,286	2,968	2,312	2,923
Weighted-average common shares for diluted net income per share (shares)		154,536	157,483	154,921	157,409
Basic (in USD per share)		$ 0.46	$ 0.36	$ 0.85	$ 0.78
Diluted (in USD per share)		$ 0.45	$ 0.35	$ 0.84	$ 0.77
Anti-dilutive employee stock-based awards excluded (shares)	[1]	2,886	1,190	2,649	1,859

[1] These employee stock-based awards 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.