Segments and Entity-Wide Disclosures - Revenue by Major Customers (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2019	Apr. 30, 2018
Revenue, Major Customer [Line Items]
Total revenue	$ 865,011	$ 729,978	$ 1,643,538	$ 1,376,113
Customer concentration risk | Sales revenue, net
Revenue, Major Customer [Line Items]
Total revenue	214,766	85,419	572,565	176,065
AT&T | Customer concentration risk | Sales revenue, net
Revenue, Major Customer [Line Items]
Total revenue	108,416	$ 85,419	202,587	$ 176,065
Verizon | Customer concentration risk | Sales revenue, net
Revenue, Major Customer [Line Items]
Total revenue	$ 106,350		195,125
Web-scale provider | Customer concentration risk | Sales revenue, net
Revenue, Major Customer [Line Items]
Total revenue			$ 174,853