Business Combinations - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2021	Oct. 31, 2020	Oct. 31, 2019
Business Acquisition [Line Items]
Goodwill	$ 3,575,785	$ 3,365,114	$ 3,171,179
Acquisition-Related Transaction Costs	15,400	14,100
Semiconductor And System Design
Business Acquisition [Line Items]
Goodwill	3,104,474	2,939,512	2,758,926
Software Integrity
Business Acquisition [Line Items]
Goodwill	471,311	425,602	$ 412,253
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Total purchase consideration	298,900	238,300
Identifiable intangibles assets acquired	109,300	65,300
Goodwill	204,500	173,700
Goodwill, expected tax deductible amount	34,000
Series of Individually Immaterial Business Acquisitions | Semiconductor And System Design
Business Acquisition [Line Items]
Goodwill	158,800	160,400
Series of Individually Immaterial Business Acquisitions | Software Integrity
Business Acquisition [Line Items]
Goodwill	$ 45,700	$ 13,300