Business Combinations - Purchase Price Allocation (Details) - USD ($) $ in Thousands	Oct. 31, 2018	Oct. 01, 2018	Jul. 02, 2018	Oct. 31, 2017	Feb. 01, 2016
Business Acquisition [Line Items]
Goodwill	$ 297,968			$ 267,458
Packet Design, LLC
Business Acquisition [Line Items]
Cash and cash equivalents			$ 642
Accounts receivable			1,525
Prepaid expenses and other long term assets			450
Equipment, furniture and fixtures			31
Goodwill			20,304
Accounts payable			(165)
Accrued liabilities			(657)
Deferred revenue			(5,176)
Total purchase price			41,054
Packet Design, LLC | Customer relationships and contracts
Business Acquisition [Line Items]
Intangible assets acquired			2,200
Packet Design, LLC | Developed technology
Business Acquisition [Line Items]
Intangible assets acquired			$ 21,900
DonRiver Holdings, LLC
Business Acquisition [Line Items]
Cash and cash equivalents		$ 1,025
Accounts receivable		4,790
Prepaid expenses and other long term assets		372
Goodwill		10,453
Deferred revenue		(193)
Other current and long term liabilities		(9,664)
Total purchase price		54,183
DonRiver Holdings, LLC | Customer relationships and contracts
Business Acquisition [Line Items]
Intangible assets acquired		37,700
DonRiver Holdings, LLC | Developed technology
Business Acquisition [Line Items]
Intangible assets acquired		$ 9,700
TeraXion Inc.
Business Acquisition [Line Items]
Inventory					$ 119
Equipment, furniture and fixtures					1,381
Goodwill					10,083
Total purchase price					32,000
TeraXion Inc. | Developed technology
Business Acquisition [Line Items]
Intangible assets acquired					16,468
TeraXion Inc. | In-process technology
Business Acquisition [Line Items]
Intangible assets acquired					$ 3,949