Net Income Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Apr. 30, 2013		Apr. 30, 2012		Apr. 30, 2013		Apr. 30, 2012
Net Income Loss Per Common Share [Line Items]
Net income	$ 68,691		$ 20,971		$ 138,613		$ 77,665
Weighted-average common shares for basic net income per share	153,515		145,948		152,496		144,877
Dilutive effect of potential common shares from equity-based compensation	3,091		3,349		3,166		3,382
Weighted-average common shares for diluted net income per share	156,606		149,297		155,662		148,259
Basic	$ 0.45		$ 0.14		$ 0.91		$ 0.54
Diluted	$ 0.44		$ 0.14		$ 0.89		$ 0.52
Anti-dilutive employee stock-based awards excluded	1,749	[1]	3,123	[1]	1,614	[1]	3,312	[1]

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