Segments and Entity-Wide Disclosures - Revenue by Major Customers (Details) - Customer concentration risk - Sales revenue, net - USD ($) $ in Thousands	3 Months Ended
Jan. 31, 2018	Jan. 31, 2017
Revenue, Major Customer [Line Items]
Revenue	$ 159,090	$ 169,526
AT&T
Revenue, Major Customer [Line Items]
Revenue	90,645	96,437
Verizon
Revenue, Major Customer [Line Items]
Revenue	$ 68,445	$ 73,089

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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