Stock Repurchase Program - Stock Repurchase Activities (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Apr. 30, 2020	[1]	Apr. 30, 2019	[2]	Apr. 30, 2020	[1]	Apr. 30, 2019	[2]
Stock Repurchase Program [Abstract]
Purchases of treasury stock (in shares)	652		780		1,231		1,126
Aggregate purchased shares	$ 100,000		$ 80,000		$ 180,000		$ 109,185
Reissuance of treasury stock	1,358		1,486		1,808		1,843

[1] Does not include the 148,953 shares and $20.0 million equity forward contract, respectively, from the February 2020 ASR settled in May 2020.

[2] Does not include the 97,601 shares and $20.0 million equity forward contract, respectively, from the February 2019 ASR settled in May 2019.