Other Income (Loss), net (Narrative) (Details) - A10 Networks $ in Millions	12 Months Ended
Oct. 31, 2015 USD ($)
Component of Other Income, Nonoperating
Gain Litigation Settlement Date	May 20, 2013
Other Nonoperating Income	$ 76.8
Note Receivable Interest Rate	8.00%
Cash
Component of Other Income, Nonoperating
Other Nonoperating Income	$ 5.0
Notes Receivable
Component of Other Income, Nonoperating
Other Nonoperating Income	$ 70.0

The aggregate amount of other income amounts, the components of which are not separately disclosed on the income statement, resulting from ancillary business-related activities (that is, excluding major activities considered part of the normal operations of the business) also known as other nonoperating income recognized for the period. Such amounts may include: (a) dividends, (b) interest on securities, (c) profits on securities (net of losses), and (d) miscellaneous other income items.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 7
-Article 5

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration