Segments and Entity-Wide Disclosures - Revenue by Major Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Revenue, Major Customer [Line Items]
Total revenue	$ 960,606	$ 818,817	$ 2,604,144	$ 2,194,930
Customer concentration risk | Sales revenue, net
Revenue, Major Customer [Line Items]
Total revenue	242,128	270,856	909,155	484,928
AT&T | Customer concentration risk | Sales revenue, net
Revenue, Major Customer [Line Items]
Total revenue		87,389	297,049	263,453
Verizon | Customer concentration risk | Sales revenue, net
Revenue, Major Customer [Line Items]
Total revenue	118,875	97,103	314,000	$ 221,475
Web-scale provider | Customer concentration risk | Sales revenue, net
Revenue, Major Customer [Line Items]
Total revenue	$ 123,253	$ 86,364	$ 298,106