Business Combinations - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended	6 Months Ended
	Dec. 11, 2017	Apr. 30, 2018	Apr. 30, 2018	Apr. 30, 2017	Oct. 31, 2017
Business Acquisition [Line Items]
Payments to acquire businesses, net of cash, cash equivalents and short-term investments			$ 631,100
Goodwill		$ 3,147,124	3,147,124		$ 2,706,974
Payment to acquire business net of cash acquired			643,537	$ 187,624
Black Duck Software
Business Acquisition [Line Items]
Payments to acquire businesses, net of cash, cash equivalents and short-term investments			544,000
Consideration transfered	$ 565,100		565,088
Goodwill		396,346	396,346
Identifiable intangibles assets acquired		178,000	178,000
Acquisition-related costs		1,900	13,500
Fair value of equity awards acquired			15,600
Fair value of assumed equity awards allocated to purchase consideration			1,588
Fair value of stock options assumed			14,000
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Goodwill		38,400	38,400
Identifiable intangibles assets acquired		$ 50,200	50,200
Acquisition-related costs			3,300
Payment to acquire business net of cash acquired			$ 87,100
Minimum | Black Duck Software
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life			1 year
Minimum | Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life			1 year
Maximum | Black Duck Software
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life			10 years
Maximum | Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life			7 years