Guarantor And Non-Guarantor Subsidiaries (Schedule Of Condensed Consolidated Statement Of Income) (Details) (USD $) In Thousands	3 Months Ended			9 Months Ended
	Jul. 30, 2011	Jul. 31, 2010		Jul. 30, 2011	Jul. 31, 2010
Revenues	$ 502,850	$ 504,252		$ 1,596,969	$ 1,542,523
Total net revenues	502,850	504,252	[1]	1,596,969	1,542,523	[1]
Cost of revenues	196,323	218,831	[2]	640,951	634,678	[2]
Total cost of revenues	196,323	218,831	[1]	640,951	634,678	[1]
Gross margin (loss)	306,527	285,421	[1]	956,018	907,845	[1]
Operating expenses	272,305	254,333	[2]	833,196	754,048	[2]
Total operating expenses	272,305	254,333		833,196	754,048
Income (loss) from operations	34,222	31,088		122,822	153,797
Other income (expense)	(42,585)			(84,517)
Total other income (expense)		(23,484)			(74,486)
Income (loss) before income tax provision (benefit)	(8,363)	7,604		38,305	79,311
Income tax provision (benefit)	(10,300)	(14,926)		(16,629)	(14,985)
Net income (loss)	1,937	22,530		54,934	94,296
Brocade Communications Systems, Inc. [Member]
Revenues	299,841	300,676		948,200	911,777
Intercompany revenues	15,753	26,051		76,729	74,283
Total net revenues	315,594	326,727		1,024,929	986,060
Cost of revenues	120,070	116,965	[2]	397,419	338,628	[2]
Intercompany cost of revenues	(8,122)	10,024		4,962	25,648
Total cost of revenues	111,948	126,989		402,381	364,276
Gross margin (loss)	203,646	199,738		622,548	621,784
Operating expenses	204,259	212,959	[2]	636,393	622,601	[2]
Intercompany operating expenses	(32,891)	(73,973)		(110,684)	(139,913)
Total operating expenses	171,368	138,986		525,709	482,688
Income (loss) from operations	32,278	60,752		96,839	139,096
Other income (expense)	(41,934)			(83,231)
Total other income (expense)		(10,027)			(61,998)
Income (loss) before income tax provision (benefit)	(9,656)	50,725		13,608	77,098
Income tax provision (benefit)	(3,751)	(32,463)		58,195	54,737
Net income (loss)	(5,905)	83,188		(44,587)	22,361
Subsidiary Guarantors [Member]
Revenues	7,526	9,424		22,407	42,481
Intercompany revenues	367	3,995		1,571	10,467
Total net revenues	7,893	13,419		23,978	52,948
Cost of revenues	19,209	30,470	[2]	62,416	86,480	[2]
Total cost of revenues	19,209	30,470		62,416	86,480
Gross margin (loss)	(11,316)	(17,051)		(38,438)	(33,532)
Operating expenses	14,794	14,541	[2]	43,614	49,152	[2]
Intercompany operating expenses	(6,280)	(4,372)		(19,133)	(17,762)
Total operating expenses	8,514	10,169		24,481	31,390
Income (loss) from operations	(19,830)	(27,220)		(62,919)	(64,922)
Other income (expense)	(76)			(502)
Total other income (expense)		655			2,421
Income (loss) before income tax provision (benefit)	(19,906)	(26,565)		(63,421)	(62,501)
Income tax provision (benefit)	(7,734)	17,251		(80,135)	(74,810)
Net income (loss)	(12,172)	(43,816)		16,714	12,309
Foreign Non-Guarantor Subsidiaries [Member]
Revenues	195,483	194,152		626,362	588,265
Intercompany revenues	11,211	5,921		26,521	17,156
Total net revenues	206,694	200,073		652,883	605,421
Cost of revenues	53,669	65,777	[2]	170,470	194,648	[2]
Intercompany cost of revenues	35,452	25,943		99,858	76,258
Total cost of revenues	89,121	91,720		270,328	270,906
Gross margin (loss)	117,573	108,353		382,555	334,515
Operating expenses	56,628	32,452	[2]	163,836	97,217	[2]
Intercompany operating expenses	39,171	78,345		129,817	157,675
Total operating expenses	95,799	110,797		293,653	254,892
Income (loss) from operations	21,774	(2,444)		88,902	79,623
Other income (expense)	(575)			(784)
Total other income (expense)		(14,112)			(14,909)
Income (loss) before income tax provision (benefit)	21,199	(16,556)		88,118	64,714
Income tax provision (benefit)	1,185	286		5,311	5,088
Net income (loss)	20,014	(16,842)		82,807	59,626
Consolidating Adjustments [Member]
Intercompany revenues	(27,331)	(35,967)		(104,821)	(101,906)
Total net revenues	(27,331)	(35,967)		(104,821)	(101,906)
Cost of revenues	3,375	5,619	[2]	10,646	14,922	[2]
Intercompany cost of revenues	(27,330)	(35,967)		(104,820)	(101,906)
Total cost of revenues	(23,955)	(30,348)		(94,174)	(86,984)
Gross margin (loss)	(3,376)	(5,619)		(10,647)	(14,922)
Operating expenses	(3,376)	(5,619)	[2]	(10,647)	(14,922)	[2]
Total operating expenses	$ (3,376)	$ (5,619)		$ (10,647)	$ (14,922)

[1] The three and nine months ended July 31, 2010 reflects the reclassification of SE costs from cost of revenue to sales and marketing expenses. See Note 1, "Basis of Presentation," of the Notes to Condensed Consolidated Financial Statements.

[2] As adjusted due to the reclassification of system engineer costs from cost of revenues to sales and marketing expenses. See Note 1, "Basis of Presentation," of the Notes to Condensed Consolidated Financial Statements.