Guarantor And Non-Guarantor Subsidiaries (Schedule Of Consolidated Statement Of Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Oct. 27, 2012	Jul. 28, 2012	Apr. 28, 2012	Jan. 28, 2012	Oct. 29, 2011	Jul. 30, 2011	Apr. 30, 2011	Jan. 29, 2011	Oct. 27, 2012	Oct. 29, 2011	Oct. 30, 2010
Condensed Financial Statements, Captions [Line Items]
Revenues									$ 2,237,770	$ 2,147,442	$ 2,091,153
Intercompany revenues									0	0	0
Total net revenues	578,357	555,332	543,439	560,642	550,472	502,850	548,364	545,756	2,237,770	2,147,442	2,091,153
Cost of revenues									854,751	863,908	860,033
Intercompany cost of revenues									0	0	0
Total cost of revenues									854,751	863,908	860,033
Gross margin	360,690	340,478	337,082	344,769	327,515	306,527	328,609	320,883	1,383,019	1,283,534	1,231,120
Operating expenses									1,105,290	1,106,014	1,023,289
Intercompany operating expenses (income)									0	0	0
Total operating expenses									1,105,290	1,106,014	1,023,289
Income (loss) from operations	86,320	70,221	51,769	69,419	54,697	34,222	46,197	42,404	277,729	177,520	207,831
Other income (expense)									(53,328)	(98,092)	(100,861)
Income (loss) before income tax									224,401	79,428	106,970
Income tax expense (benefit)									29,220	28,818	(9,553)
Equity in net earnings (losses) of subsidiaries									0	0	0
Net income (loss)	54,001	43,300	39,296	58,584	(4,324)	1,937	26,079	26,918	195,181	50,610	116,523
Brocade Communications Systems, Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues									1,409,705	1,285,732	1,287,646
Intercompany revenues									44,152	88,063	102,178
Total net revenues									1,453,857	1,373,795	1,389,824
Cost of revenues									559,835	531,162	529,641
Intercompany cost of revenues									(35,070)	(2,263)	40,588
Total cost of revenues									524,765	528,899	570,229
Gross margin									929,092	844,896	819,595
Operating expenses									827,318	821,018	783,968
Intercompany operating expenses (income)									(138,197)	(138,789)	(167,746)
Total operating expenses									689,121	682,229	616,222
Income (loss) from operations									239,971	162,667	203,373
Other income (expense)									(49,470)	109,902	(80,276)
Income (loss) before income tax									190,501	272,569	123,097
Income tax expense (benefit)									20,432	22,115	(20,672)
Equity in net earnings (losses) of subsidiaries									25,112	(199,844)	(27,246)
Net income (loss)									195,181	50,610	116,523
Subsidiary Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues									4,685	27,569	50,731
Intercompany revenues									0	1,753	13,954
Total net revenues									4,685	29,322	64,685
Cost of revenues									49,935	85,540	112,477
Intercompany cost of revenues									0	0	0
Total cost of revenues									49,935	85,540	112,477
Gross margin									(45,250)	(56,218)	(47,792)
Operating expenses									56,838	76,645	63,855
Intercompany operating expenses (income)									(27,319)	(25,694)	(30,349)
Total operating expenses									29,519	50,951	33,506
Income (loss) from operations									(74,769)	(107,169)	(81,298)
Other income (expense)									4	(7,518)	(1,628)
Income (loss) before income tax									(74,765)	(114,687)	(82,926)
Income tax expense (benefit)									0	46	1,266
Equity in net earnings (losses) of subsidiaries									0	0	0
Net income (loss)									(74,765)	(114,733)	(84,192)
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues									823,380	834,141	752,776
Intercompany revenues									21,709	35,980	25,464
Total net revenues									845,089	870,121	778,240
Cost of revenues									234,889	233,448	214,024
Intercompany cost of revenues									100,931	128,059	101,008
Total cost of revenues									335,820	361,507	315,032
Gross margin									509,269	508,614	463,208
Operating expenses									231,226	222,109	179,357
Intercompany operating expenses (income)									165,516	164,483	198,095
Total operating expenses									396,742	386,592	377,452
Income (loss) from operations									112,527	122,022	85,756
Other income (expense)									(3,862)	(200,476)	(18,957)
Income (loss) before income tax									108,665	(78,454)	66,799
Income tax expense (benefit)									8,788	6,657	9,853
Equity in net earnings (losses) of subsidiaries									0	0	0
Net income (loss)									99,877	(85,111)	56,946
Consolidating Adjustments [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues									0	0	0
Intercompany revenues									(65,861)	(125,796)	(141,596)
Total net revenues									(65,861)	(125,796)	(141,596)
Cost of revenues									10,092	13,758	3,891
Intercompany cost of revenues									(65,861)	(125,796)	(141,596)
Total cost of revenues									(55,769)	(112,038)	(137,705)
Gross margin									(10,092)	(13,758)	(3,891)
Operating expenses									(10,092)	(13,758)	(3,891)
Intercompany operating expenses (income)									0	0	0
Total operating expenses									(10,092)	(13,758)	(3,891)
Income (loss) from operations									0	0	0
Other income (expense)									0	0	0
Income (loss) before income tax									0	0	0
Income tax expense (benefit)									0	0	0
Equity in net earnings (losses) of subsidiaries									(25,112)	199,844	27,246
Net income (loss)									$ (25,112)	$ 199,844	$ 27,246