Segment and Entity Wide Disclosures (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2015	Oct. 31, 2014	Oct. 31, 2013	Aug. 03, 2015
Segment Reporting Information [Line Items]
Equipment, building, furniture and fixtures, net	$ 191,973	$ 126,632	$ 119,729
Goodwill	256,434	0
Maintenance spares inventory, net	55,259	54,101
Revenue:
Revenue	2,445,669	2,288,289	2,082,546
Segment profit (loss) and the reconciliation to consolidated net income (loss)
Segment profit (loss)	661,362	547,172	481,767
Less: non-performance operating expenses
Selling and marketing	333,836	328,325	304,170
General and administrative	123,402	126,824	122,432
Amortization of intangible assets	69,511	45,970	49,771
Acquisition and integration costs	25,539	0	0
Restructuring costs	8,626	349	7,169
Add: other non-performance financial items
Interest expense and other income (loss), net	(76,684)	(72,377)	(49,786)
Loss on extinguishment of debt	0	0	(28,630)
Less: Provision for income taxes	12,097	13,964	5,240
Net income (loss)	11,667	(40,637)	(85,431)
Converged Packet Optical
Segment Reporting Information [Line Items]
Intangible assets including goodwill	166,500
Revenue:
Revenue	1,661,702	1,455,501	1,187,231
Segment profit (loss) and the reconciliation to consolidated net income (loss)
Segment profit (loss)	471,484	353,942	242,335
Packet Networking
Revenue:
Revenue	229,223	244,116	222,898
Segment profit (loss) and the reconciliation to consolidated net income (loss)
Segment profit (loss)	28,136	19,467	22,740
Optical Transport
Revenue:
Revenue	73,004	127,215	233,821
Segment profit (loss) and the reconciliation to consolidated net income (loss)
Segment profit (loss)	15,930	38,974	89,754
Software and Services
Segment Reporting Information [Line Items]
Intangible assets including goodwill	292,600
Revenue:
Revenue	481,740	461,457	438,596
Segment profit (loss) and the reconciliation to consolidated net income (loss)
Segment profit (loss)	145,812	$ 134,789	$ 126,938
Cyan, Inc
Segment Reporting Information [Line Items]
Goodwill				$ 256,434
Less: non-performance operating expenses
Acquisition and integration costs	25,500
Cyan, Inc | Converged Packet Optical
Segment Reporting Information [Line Items]
Goodwill	55,000			55,000
Cyan, Inc | Software and Services
Segment Reporting Information [Line Items]
Goodwill	$ 201,400			$ 201,400