Segments and Entity-Wide Disclosures - Revenue, Profit (Loss) and Net Income (Loss) Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended
Jan. 31, 2018	Jan. 31, 2017
Revenue:
Revenue	$ 646,135	$ 621,497
Segment profit:
Operating income (loss)	16,736	19,104
Less: Non-performance operating expenses
Selling and marketing	88,515	85,002
General and administrative	38,406	35,864
Amortization of intangible assets	3,623	14,551
Significant asset impairments and restructuring costs	5,961	2,395
Add: Other non-performance financial items
Interest expense and other income (loss), net	(12,159)	(14,833)
Less: Provision for income taxes	477,940	410
Net income (loss)	(473,363)	3,861
Networking Platforms
Revenue:
Revenue	496,033	489,944
Networking Platforms \| Converged Packet Optical
Revenue:
Revenue	427,401	417,750
Networking Platforms \| Packet Networking
Revenue:
Revenue	68,632	72,194
Software and Software-Related Services
Revenue:
Revenue	53,487	39,380
Software and Software-Related Services \| Software Platforms
Revenue:
Revenue	29,576	17,049
Software and Software-Related Services \| Software-Related Services
Revenue:
Revenue	23,911	22,331
Global Services
Revenue:
Revenue	96,615	92,173
Global Services \| Maintenance Support and Training
Revenue:
Revenue	55,958	54,990
Global Services \| Installation and Deployment
Revenue:
Revenue	30,016	27,919
Global Services \| Consulting and Network Design
Revenue:
Revenue	10,641	9,264
Operating Segments
Segment profit:
Operating income (loss)	153,241	156,916
Operating Segments \| Networking Platforms
Segment profit:
Operating income (loss)	88,569	113,747
Operating Segments \| Software and Software-Related Services
Segment profit:
Operating income (loss)	23,635	7,700
Operating Segments \| Global Services
Segment profit:
Operating income (loss)	$ 41,037	$ 35,469

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