Goodwill And Intangible Assets (Schedule Of Goodwill Activity By Reportable Segment) (Details) $ in Thousands	6 Months Ended
	Apr. 30, 2016 USD ($)
Goodwill
Goodwill, Gross, Beginning Balance	$ 1,746,375
Accumulated impairment losses, Beginning Balance	(129,214)
Goodwill, Net, Beginning Balance	1,617,161
Acquisitions (1)	4,625
Goodwill, Tax and other adjustments	(5)	[1]
Goodwill, Translation Adjustments	(90)
Goodwill, Gross, Ending Balance	1,750,905
Accumulated impairment losses, Ending Balance	(129,214)
Goodwill, Net, Ending Balance	1,621,691
Storage Area Networking (“SAN”) Products
Goodwill
Goodwill, Gross, Beginning Balance	176,325
Accumulated impairment losses, Beginning Balance	0
Goodwill, Net, Beginning Balance	176,325
Acquisitions (1)	0
Goodwill, Tax and other adjustments	(5)	[1]
Goodwill, Translation Adjustments	0
Goodwill, Gross, Ending Balance	176,320
Accumulated impairment losses, Ending Balance	0
Goodwill, Net, Ending Balance	176,320
IP Networking Products
Goodwill
Goodwill, Gross, Beginning Balance	1,414,634
Accumulated impairment losses, Beginning Balance	(129,214)
Goodwill, Net, Beginning Balance	1,285,420
Acquisitions (1)	4,625
Goodwill, Tax and other adjustments	0	[1]
Goodwill, Translation Adjustments	(90)
Goodwill, Gross, Ending Balance	1,419,169
Accumulated impairment losses, Ending Balance	(129,214)
Goodwill, Net, Ending Balance	1,289,955
Global Services
Goodwill
Goodwill, Gross, Beginning Balance	155,416
Accumulated impairment losses, Beginning Balance	0
Goodwill, Net, Beginning Balance	155,416
Acquisitions (1)	0
Goodwill, Tax and other adjustments	0	[1]
Goodwill, Translation Adjustments	0
Goodwill, Gross, Ending Balance	155,416
Accumulated impairment losses, Ending Balance	0
Goodwill, Net, Ending Balance	$ 155,416

[1] The goodwill adjustments were primarily a result of tax benefits from the exercise of stock awards of acquired companies.