Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2015	Nov. 01, 2014		Oct. 26, 2013
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%	35.00%		35.00%
Goodwill impairment charge	$ 0	$ 83,382	[1]	$ 0
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount				78,200
Undistributed earnings of the foreign subsidiaries	873,800
Cash, cash equivalents and short-term investments	$ 1,440,900
Percentage of cash and cash equivalents and short term investments held in foreign subsidiaries	61.00%
Percentage Of Tax Benefit Realized Upon Ultimate Settlement With Taxing Authority	50.00%
Amount of unrecognized tax benefits that could affect the effect tax rate	$ 79,000
Lower range of estimated potential decreases in underlying uncertain tax positions	0
Upper range of estimated potential decreases in underlying uncertain tax positions	4,000
Tax benefit (detriment) from employee stock plans	48,000	59,900		$ (1,500)
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	200	(16)
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	2,500	$ 2,300
Internal Revenue Service (IRS)
Operating loss carryforwards	90,900
Tax credit carryforward	$ 119,400
Operating loss carryforwards, Expiration Date Range	various dates between fiscal year 2017 through 2034
State and Local Jurisdiction
Tax credit carryforward	$ 178,700
Operating loss carryforwards, Expiration Date Range	various dates between fiscal year 2015 through 2032
California State
Operating loss carryforwards	$ 49,700
Other States
Operating loss carryforwards	$ 135,300

[1] In the second quarter of fiscal year 2014, the Company made a strategic change in the allocation of its engineering resources by reducing its investment in engineering and sales for the hardware-based Brocade ADX products and increasing engineering investment in the software-based Brocade ADX products for Layer 4-7 applications. As a result of this change in strategy, the Company expected hardware-based Brocade ADX and related support revenue to be negatively impacted. Based on these changes in estimates, the Company recognized an impairment charge during the second fiscal quarter of 2014 because the book value of its Application Delivery Products (“ADP”) reporting unit net assets, which includes the Brocade ADX products, exceeded the estimated fair value of these assets. The goodwill amount related to the Company’s other reporting units was not impacted.