Stock Repurchase Program - Stock Repurchase Activities (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Apr. 30, 2021	[1]	Apr. 30, 2020	[2]	Apr. 30, 2021	Apr. 30, 2020	[2]
Stock Repurchase Program [Abstract]
Purchases of treasury stock (in shares)	756		652		1,593	1,231
Aggregate purchased shares	$ 195,211		$ 100,000		$ 398,082	$ 180,000
Reissuance of treasury stock	946		1,358		1,529	1,808

[1] Includes the 166,276 shares and $50.0 million equity forward contract, respectively, from the December 2020 ASR.

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