Stock Repurchase Program - Stock Repurchase Activities (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended	6 Months Ended
Apr. 30, 2019	Jan. 31, 2019	Apr. 30, 2018	Jan. 31, 2018	Apr. 30, 2019	Apr. 30, 2018
Stock Repurchase Program [Abstract]
Purchases of treasury stock (in shares)	780		916		1,126	2,902
Aggregate purchased shares	$ 80,000	$ 29,185	$ 75,000	$ 180,000	$ 109,185	$ 255,000
Reissuance of treasury stock	1,486		924		1,843	1,419

Number of treasury shares (units) reissued during the period, excluding reissuance of shares (units) held in treasury used to satisfy equity-based compensation obligations exercised by the holders of such rights. Upon reissuance of shares (units) from treasury, either the common or preferred stock (unit) reissued is outstanding.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration