Guarantor And Non-Guarantor Subsidiaries (Schedule Of Condensed Consolidated Statement Of Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jan. 28, 2012	Jan. 29, 2011
Guarantor Obligations [Line Items]
Net cash provided (used in) by operating activities	$ 127,051	$ 118,236
Purchases of short-term investments		(25)
Proceeds from sale of subsidiary	(215)
Proceeds from maturities and sale of short-term investments		19
Purchases of property and equipment	(17,556)	(23,395)
Net cash used in investing activities	(17,771)	(23,401)
Payment of principal related to the term loan	(70,000)	(39,748)
Payment of principal related to capital leases	(456)	(431)
Proceeds from issuance of common stock	31,941	25,477
Excess tax benefits from stock-based compensation	1,147
Net cash used in financing activities	(37,368)	(14,702)
Effect of exchange rate fluctuations on cash and cash equivalents	(1,875)	66
Net increase in cash and cash equivalents	70,037	80,199
Cash and cash equivalents, beginning of period	414,202	333,984
Cash and cash equivalents, end of period	484,239	414,183
Brocade Communications Systems, Inc. [Member]
Guarantor Obligations [Line Items]
Net cash provided (used in) by operating activities	116,939	52,648
Proceeds from sale of subsidiary	(215)
Purchases of property and equipment	(15,241)	(20,564)
Net cash used in investing activities	(15,456)	(20,564)
Payment of principal related to the term loan	(70,000)	(39,748)
Payment of principal related to capital leases	(456)	(431)
Proceeds from issuance of common stock	31,941	25,477
Excess tax benefits from stock-based compensation	1,147
Net cash used in financing activities	(37,368)	(14,702)
Net increase in cash and cash equivalents	64,115	17,382
Cash and cash equivalents, beginning of period	101,366	23,455
Cash and cash equivalents, end of period	165,481	40,837
Subsidiary Guarantors [Member]
Guarantor Obligations [Line Items]
Net cash provided (used in) by operating activities	(113)	840
Purchases of short-term investments		(25)
Proceeds from maturities and sale of short-term investments		19
Purchases of property and equipment		(8)
Net cash used in investing activities		(14)
Net increase in cash and cash equivalents	(113)	826
Cash and cash equivalents, beginning of period	1,528	6,907
Cash and cash equivalents, end of period	1,415	7,733
Non-Guarantor Subsidiaries [Member]
Guarantor Obligations [Line Items]
Net cash provided (used in) by operating activities	10,225	64,748
Purchases of property and equipment	(2,315)	(2,823)
Net cash used in investing activities	(2,315)	(2,823)
Effect of exchange rate fluctuations on cash and cash equivalents	(1,875)	66
Net increase in cash and cash equivalents	6,035	61,991
Cash and cash equivalents, beginning of period	311,308	303,622
Cash and cash equivalents, end of period	317,343	365,613
Consolidating Adjustments [Member]
Guarantor Obligations [Line Items]
Net cash provided (used in) by operating activities
Purchases of short-term investments
Proceeds from sale of subsidiary
Proceeds from maturities and sale of short-term investments
Purchases of property and equipment
Net cash used in investing activities
Payment of principal related to the term loan
Payment of principal related to capital leases
Proceeds from issuance of common stock
Excess tax benefits from stock-based compensation
Net cash used in financing activities
Effect of exchange rate fluctuations on cash and cash equivalents
Net increase in cash and cash equivalents
Cash and cash equivalents, beginning of period
Cash and cash equivalents, end of period