Business Combinations - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Apr. 30, 2020	Apr. 30, 2020	Oct. 31, 2019	[1]
Business Acquisition [Line Items]
Goodwill	$ 3,311,243	$ 3,311,243	$ 3,171,179
Design service arrangement	$ 10,700	10,700
Design service arrangement amortization period	5 years
Semiconductor & System Design:
Business Acquisition [Line Items]
Consideration transfered	$ 105,700
Consideration transfered, cash	75,700
Consideration transfered, fair value of company product	30,000
Identifiable intangibles assets acquired	20,600	20,600
Tangibles assets acquired	4,200	4,200
Goodwill	80,900	80,900
Several other acquisitions
Business Acquisition [Line Items]
Consideration transfered		79,800
Identifiable intangibles assets acquired	25,200	25,200
Goodwill	55,900	55,900
Several other acquisitions | Software Integrity
Business Acquisition [Line Items]
Goodwill	$ 12,900	$ 12,900

[1] Derived from audited financial statements.