Segments and Entity-Wide Disclosures - Revenue, Profit (Loss) and Net Income (Loss) Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended
Jan. 31, 2019	Jan. 31, 2018
Revenue:
Total revenue	$ 778,527	$ 646,135
Segment profit:
Operating income (loss)	47,943	16,736
Less: Non-performance operating expenses
Selling and marketing	98,113	88,515
General and administrative	39,243	38,406
Significant asset impairments and restructuring costs	2,273	5,961
Amortization of intangible assets	5,528	3,623
Acquisition and integration costs	1,608	0
Add: Other non-performance financial items
Interest expense and other income, net	(5,188)	(12,159)
Less: Provision for income taxes	9,139	477,940
Net income (loss)	33,616	(473,363)
Operating Segments
Segment profit:
Operating income (loss)	194,708	153,241
Operating Segments \| Networking Platforms
Revenue:
Total revenue	620,566	496,033
Segment profit:
Operating income (loss)	136,590	88,569
Operating Segments \| Software and Software-Related Services
Revenue:
Total revenue	56,572	53,487
Segment profit:
Operating income (loss)	18,417	23,635
Operating Segments \| Global Services
Revenue:
Total revenue	101,389	96,615
Segment profit:
Operating income (loss)	39,701	41,037
Converged Packet Optical
Revenue:
Total revenue	548,997
Converged Packet Optical \| Operating Segments \| Networking Platforms
Revenue:
Total revenue	548,997	427,401
Converged Packet Optical \| Operating Segments \| Software and Software-Related Services
Revenue:
Total revenue	0
Converged Packet Optical \| Operating Segments \| Global Services
Revenue:
Total revenue	0
Packet Networking
Revenue:
Total revenue	71,569
Packet Networking \| Operating Segments \| Networking Platforms
Revenue:
Total revenue	71,569	68,632
Packet Networking \| Operating Segments \| Software and Software-Related Services
Revenue:
Total revenue	0
Packet Networking \| Operating Segments \| Global Services
Revenue:
Total revenue	0
Platform Software and Services
Revenue:
Total revenue	41,598
Platform Software and Services \| Operating Segments \| Networking Platforms
Revenue:
Total revenue	0
Platform Software and Services \| Operating Segments \| Software and Software-Related Services
Revenue:
Total revenue	41,598	44,136
Platform Software and Services \| Operating Segments \| Global Services
Revenue:
Total revenue	0
Blue Planet Automation Software and Services
Revenue:
Total revenue	14,974
Blue Planet Automation Software and Services \| Operating Segments \| Networking Platforms
Revenue:
Total revenue	0
Blue Planet Automation Software and Services \| Operating Segments \| Software and Software-Related Services
Revenue:
Total revenue	14,974	9,351
Blue Planet Automation Software and Services \| Operating Segments \| Global Services
Revenue:
Total revenue	0
Maintenance Support and Training
Revenue:
Total revenue	61,277
Maintenance Support and Training \| Operating Segments \| Networking Platforms
Revenue:
Total revenue	0
Maintenance Support and Training \| Operating Segments \| Software and Software-Related Services
Revenue:
Total revenue	0
Maintenance Support and Training \| Operating Segments \| Global Services
Revenue:
Total revenue	61,277	55,958
Installation and Deployment
Revenue:
Total revenue	30,622
Installation and Deployment \| Operating Segments \| Networking Platforms
Revenue:
Total revenue	0
Installation and Deployment \| Operating Segments \| Software and Software-Related Services
Revenue:
Total revenue	0
Installation and Deployment \| Operating Segments \| Global Services
Revenue:
Total revenue	30,622	30,016
Consulting and Network Design
Revenue:
Total revenue	9,490
Consulting and Network Design \| Operating Segments \| Networking Platforms
Revenue:
Total revenue	0
Consulting and Network Design \| Operating Segments \| Software and Software-Related Services
Revenue:
Total revenue	0
Consulting and Network Design \| Operating Segments \| Global Services
Revenue:
Total revenue	$ 9,490	$ 10,641

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