Guarantor And Non-Guarantor Subsidiaries (Schedule Of Consolidated Statement Of Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Apr. 28, 2012	Apr. 30, 2011	Apr. 28, 2012	Apr. 30, 2011
Condensed Financial Statements, Captions [Line Items]
Revenues	$ 543,439	$ 548,364	$ 1,104,081	$ 1,094,120
Intercompany revenues	0	0	0	0
Total net revenues	543,439	548,364	1,104,081	1,094,120
Cost of revenues	206,357	219,755	422,230	444,628
Intercompany cost of revenues	0	0	0	0
Total cost of revenues	206,357	219,755	422,230	444,628
Gross margin	337,082	328,609	681,851	649,492
Operating expenses	285,313	282,412	560,663	560,891
Intercompany operating expenses	0	0	0	0
Total operating expenses	285,313	282,412	560,663	560,891
Income from operations	51,769	46,197	121,188	88,601
Other income (expense)	(13,181)	(20,729)	(27,223)	(41,932)
Income before income tax benefit	38,588	25,468	93,965	46,669
Income tax provision (benefit)	(708)	(611)	(3,915)	(6,328)
Equity in net earnings (losses) of subsidiaries	0	0	0	0
Net income (loss)	39,296	26,079	97,880	52,997
Brocade Communications Systems, Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	352,760	321,440	692,904	648,360
Intercompany revenues	13,947	29,958	24,607	60,976
Total net revenues	366,707	351,398	717,511	709,336
Cost of revenues	141,052	137,612	272,188	277,349
Intercompany cost of revenues	(6,792)	6,909	(15,166)	13,084
Total cost of revenues	134,260	144,521	257,022	290,433
Gross margin	232,447	206,877	460,489	418,903
Operating expenses	216,870	219,252	415,125	432,134
Intercompany operating expenses	(30,169)	(35,607)	(66,925)	(77,793)
Total operating expenses	186,701	183,645	348,200	354,341
Income from operations	45,746	23,232	112,289	64,562
Other income (expense)	(12,915)	(20,112)	(23,197)	(41,297)
Income before income tax benefit	32,831	3,120	89,092	23,265
Income tax provision (benefit)	(2,565)	(2,888)	(8,122)	(10,648)
Equity in net earnings (losses) of subsidiaries	3,900	20,071	666	19,084
Net income (loss)	39,296	26,079	97,880	52,997
Subsidiary Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	1,250	7,417	2,739	14,881
Intercompany revenues	0	427	0	1,204
Total net revenues	1,250	7,844	2,739	16,085
Cost of revenues	10,852	22,552	27,988	43,207
Intercompany cost of revenues	0	0	0	0
Total cost of revenues	10,852	22,552	27,988	43,207
Gross margin	(9,602)	(14,708)	(25,249)	(27,122)
Operating expenses	15,162	12,591	30,489	28,820
Intercompany operating expenses	(6,539)	(6,472)	(12,561)	(12,853)
Total operating expenses	8,623	6,119	17,928	15,967
Income from operations	(18,225)	(20,827)	(43,177)	(43,089)
Other income (expense)	(111)	312	(106)	(426)
Income before income tax benefit	(18,336)	(20,515)	(43,283)	(43,515)
Income tax provision (benefit)	0	11		11
Equity in net earnings (losses) of subsidiaries	0	0	0	0
Net income (loss)	(18,336)	(20,526)	(43,283)	(43,526)
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	189,429	219,507	408,438	430,879
Intercompany revenues	7,349	7,598	14,069	15,310
Total net revenues	196,778	227,105	422,507	446,189
Cost of revenues	51,546	55,917	116,924	116,801
Intercompany cost of revenues	28,088	31,074	53,842	64,406
Total cost of revenues	79,634	86,991	170,766	181,207
Gross margin	117,144	140,114	251,741	264,982
Operating expenses	56,188	54,243	120,179	107,208
Intercompany operating expenses	36,708	42,079	79,486	90,646
Total operating expenses	92,896	96,322	199,665	197,854
Income from operations	24,248	43,792	52,076	67,128
Other income (expense)	(155)	(929)	(3,920)	(209)
Income before income tax benefit	24,093	42,863	48,156	66,919
Income tax provision (benefit)	1,857	2,266	4,207	4,309
Equity in net earnings (losses) of subsidiaries	0	0	0	0
Net income (loss)	22,236	40,597	43,949	62,610
Consolidating Adjustments [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	0	0	0	0
Intercompany revenues	(21,296)	(37,983)	(38,676)	(77,490)
Total net revenues	(21,296)	(37,983)	(38,676)	(77,490)
Cost of revenues	2,907	3,674	5,130	7,271
Intercompany cost of revenues	(21,296)	(37,983)	(38,676)	(77,490)
Total cost of revenues	(18,389)	(34,309)	(33,546)	(70,219)
Gross margin	(2,907)	(3,674)	(5,130)	(7,271)
Operating expenses	(2,907)	(3,674)	(5,130)	(7,271)
Intercompany operating expenses	0	0	0	0
Total operating expenses	(2,907)	(3,674)	(5,130)	(7,271)
Income from operations	0	0	0	0
Other income (expense)	0	0	0	0
Income before income tax benefit	0	0	0	0
Income tax provision (benefit)	0	0	0	0
Equity in net earnings (losses) of subsidiaries	(3,900)	(20,071)	(666)	(19,084)
Net income (loss)	$ (3,900)	$ (20,071)	$ (666)	$ (19,084)