Guarantor And Non-Guarantor Subsidiaries (Schedule Of Condensed Consolidated Balance Sheet) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Jan. 28, 2012	Oct. 29, 2011
Guarantor Obligations [Line Items]
Cash, cash equivalents and short-term investments	$ 485,024	$ 414,976
Accounts receivable, net	219,363	249,141
Inventories	80,999	74,172
Other current assets	109,682	105,912
Total current assets	895,068	844,201
Property and equipment, net	528,102	532,384
Other non-current assets	2,055,570	2,097,723
Total assets	3,478,740	3,474,308
Accounts payable	99,184	109,471
Current portion of long-term debt	27,341	40,539
Other current liabilities	405,982	415,977
Total current liabilities	532,507	565,987
Total long-term debt, net of current portion	692,191	748,904
Other non-current liabilities	132,674	145,279
Total liabilities	1,357,372	1,460,170
Total stockholders' equity	2,121,368	2,014,138
Total liabilities and stockholders' equity	3,478,740	3,474,308
Brocade Communications Systems, Inc. [Member]
Guarantor Obligations [Line Items]
Cash, cash equivalents and short-term investments	165,481	101,367
Accounts receivable, net	116,624	157,839
Inventories	53,159	50,000
Other current assets	94,761	87,495
Total current assets	430,025	396,701
Property and equipment, net	455,867	460,347
Investment in subsidiaries	1,277,575	1,285,356
Other non-current assets	1,493,148	1,506,086
Total assets	3,656,615	3,648,490
Accounts payable	76,420	85,700
Current portion of long-term debt	27,341	40,539
Intercompany payables	387,867	377,228
Other current liabilities	260,660	276,982
Total current liabilities	752,288	780,449
Total long-term debt, net of current portion	692,191	748,904
Other non-current liabilities	90,768	104,999
Total liabilities	1,535,247	1,634,352
Total stockholders' equity	2,121,368	2,014,138
Total liabilities and stockholders' equity	3,656,615	3,648,490
Subsidiary Guarantors [Member]
Guarantor Obligations [Line Items]
Cash, cash equivalents and short-term investments	2,200	2,301
Accounts receivable, net	(1,932)	(2,149)
Intercompany receivables	449,755	446,455
Other current assets	740	805
Total current assets	450,763	447,412
Property and equipment, net	55,128	55,594
Other non-current assets	561,087	590,318
Total assets	1,066,978	1,093,324
Accounts payable	357	376
Other current liabilities	16,060	17,261
Total current liabilities	16,417	17,637
Other non-current liabilities	401	580
Total liabilities	16,818	18,217
Total stockholders' equity	1,050,160	1,075,107
Total liabilities and stockholders' equity	1,066,978	1,093,324
Non-Guarantor Subsidiaries [Member]
Guarantor Obligations [Line Items]
Cash, cash equivalents and short-term investments	317,343	311,308
Accounts receivable, net	104,671	93,451
Inventories	27,840	24,172
Other current assets	10,954	15,609
Total current assets	460,808	444,540
Property and equipment, net	17,107	16,443
Other non-current assets	1,335	1,319
Total assets	479,250	462,302
Accounts payable	22,407	23,395
Intercompany payables	61,888	69,227
Other current liabilities	126,035	119,731
Total current liabilities	210,330	212,353
Other non-current liabilities	41,505	39,700
Total liabilities	251,835	252,053
Total stockholders' equity	227,415	210,249
Total liabilities and stockholders' equity	479,250	462,302
Consolidating Adjustments [Member]
Guarantor Obligations [Line Items]
Intercompany receivables	(449,755)	(446,455)
Other current assets	3,227	2,003
Total current assets	(446,528)	(444,452)
Investment in subsidiaries	(1,277,575)	(1,285,356)
Total assets	(1,724,103)	(1,729,808)
Intercompany payables	(449,755)	(446,455)
Other current liabilities	3,227	2,003
Total current liabilities	(446,528)	(444,452)
Total liabilities	(446,528)	(444,452)
Total stockholders' equity	(1,277,575)	(1,285,356)
Total liabilities and stockholders' equity	$ (1,724,103)	$ (1,729,808)