Segments and Entity-Wide Disclosures - Revenue by Major Customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Jan. 31, 2019	Jan. 31, 2018
Revenue, Major Customer [Line Items]
Total revenue	$ 778,527	$ 646,135
Customer concentration risk | Sales revenue, net
Revenue, Major Customer [Line Items]
Total revenue	272,461	159,090
AT&T | Customer concentration risk | Sales revenue, net
Revenue, Major Customer [Line Items]
Total revenue	94,172	90,645
Web-scale provider | Customer concentration risk | Sales revenue, net
Revenue, Major Customer [Line Items]
Total revenue	89,514
Verizon | Customer concentration risk | Sales revenue, net
Revenue, Major Customer [Line Items]
Total revenue	$ 88,775	$ 68,445