Stock Repurchase Program - Stock Repurchase Activities (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended			6 Months Ended
	Apr. 30, 2015		Apr. 30, 2014	Apr. 30, 2015		Apr. 30, 2014
Stock Repurchase Program
Shares repurchased	0		628	3,290		2,050
Average purchase price	$ 0.00		$ 39.81	$ 43.77		$ 38.90
Payments for Repurchase of Common Stock	$ 0	[1]	$ 25,000	$ 144,000	[1]	$ 79,747
Reissuance of treasury stock	1,597		1,281	2,379		2,587

[1] Does not include $36.0 million equity forward contract related to the above-referenced 2015 ASR.