Guarantor And Non-Guarantor Subsidiaries (Schedule Of Consolidated Statement Of Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Oct. 27, 2012	Oct. 29, 2011	Oct. 30, 2010
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ 590,870	$ 449,232	$ 298,513
Purchases of short-term investments	0	(38)	(53)
Purchases of non-marketable minority equity investments	0	0	(200)
Proceeds from maturities and sale of short-term investments	952	1,604	3,255
Proceeds from sale of property	0	0	30,185
Proceeds from sale of subsidiary	35	3,905	0
Purchases of property and equipment	(72,797)	(96,797)	(201,621)
Net cash provided by (used in) investing activities	(71,810)	(91,326)	(168,434)
Payment of debt issuance costs related to the senior secured notes	0	0	(3,666)
Payment of principal related to the revolving credit facility	0	0	(14,050)
Payment of principal related to the convertible subordinated debt	0	0	(172,500)
Payment of principal related to the term loan	(190,000)	(359,898)	(583,029)
Payment of fees related to the term loan	0	(1,167)	0
Proceeds from term loan	0	198,950	0
Payment of principal related to capital leases	(1,866)	(1,761)	(1,173)
Common stock repurchases	(130,209)	(210,698)	(25,004)
Proceeds from senior secured notes	0	0	587,968
Proceeds from issuance of common stock	98,791	97,152	81,593
Excess tax benefits (detriments) from stock-based compensation	5,141	312	2,161
Net cash provided by (used in) financing activities	(218,143)	(277,110)	(127,700)
Effect of exchange rate fluctuations on cash and cash equivalents	(1,893)	(578)	(2,588)
Net increase (decrease) in cash and cash equivalents	299,024	80,218	(209)
Cash and cash equivalents, beginning of period	414,202	333,984	334,193
Cash and cash equivalents, end of period	713,226	414,202	333,984
Brocade Communications Systems, Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	464,097	436,714	71,094
Purchases of short-term investments		0	0
Purchases of non-marketable minority equity investments			(200)
Proceeds from maturities and sale of short-term investments	0	0	0
Proceeds from sale of property			30,185
Proceeds from sale of subsidiary	35	4,966
Purchases of property and equipment	(62,791)	(86,447)	(196,193)
Net cash provided by (used in) investing activities	(62,756)	(81,481)	(166,208)
Payment of debt issuance costs related to the senior secured notes			(3,666)
Payment of principal related to the revolving credit facility			(14,050)
Payment of principal related to the convertible subordinated debt			0
Payment of principal related to the term loan	(190,000)	(359,898)	(583,029)
Payment of fees related to the term loan		(1,167)
Proceeds from term loan		198,950
Payment of principal related to capital leases	(1,866)	(1,761)	(1,173)
Common stock repurchases	(130,209)	(210,698)	(25,004)
Proceeds from senior secured notes			587,968
Proceeds from issuance of common stock	98,791	97,152	81,593
Excess tax benefits (detriments) from stock-based compensation	5,042	101	1,420
Net cash provided by (used in) financing activities	(218,242)	(277,321)	44,059
Effect of exchange rate fluctuations on cash and cash equivalents	0	0	0
Net increase (decrease) in cash and cash equivalents	183,099	77,912	(51,055)
Cash and cash equivalents, beginning of period	101,367	23,455	74,510
Cash and cash equivalents, end of period	284,466	101,367	23,455
Subsidiary Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(1,799)	(5,852)	169,986
Purchases of short-term investments		(38)	(53)
Purchases of non-marketable minority equity investments			0
Proceeds from maturities and sale of short-term investments	952	1,604	3,255
Proceeds from sale of property			0
Proceeds from sale of subsidiary	0	(1,061)
Purchases of property and equipment	0	(33)	471
Net cash provided by (used in) investing activities	952	472	3,673
Payment of debt issuance costs related to the senior secured notes			0
Payment of principal related to the revolving credit facility			0
Payment of principal related to the convertible subordinated debt			(172,500)
Payment of principal related to the term loan	0	0	0
Payment of fees related to the term loan		0
Proceeds from term loan		0
Payment of principal related to capital leases	0	0	0
Common stock repurchases	0	0	0
Proceeds from senior secured notes			0
Proceeds from issuance of common stock	0	0	0
Excess tax benefits (detriments) from stock-based compensation	0	0	0
Net cash provided by (used in) financing activities	0	0	(172,500)
Effect of exchange rate fluctuations on cash and cash equivalents	0	0	0
Net increase (decrease) in cash and cash equivalents	(847)	(5,380)	1,159
Cash and cash equivalents, beginning of period	1,527	6,907	5,748
Cash and cash equivalents, end of period	680	1,527	6,907
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	128,572	18,370	57,433
Purchases of short-term investments		0	0
Purchases of non-marketable minority equity investments			0
Proceeds from maturities and sale of short-term investments	0	0	0
Proceeds from sale of property			0
Proceeds from sale of subsidiary	0	0
Purchases of property and equipment	(10,006)	(10,317)	(5,899)
Net cash provided by (used in) investing activities	(10,006)	(10,317)	(5,899)
Payment of debt issuance costs related to the senior secured notes			0
Payment of principal related to the revolving credit facility			0
Payment of principal related to the convertible subordinated debt			0
Payment of principal related to the term loan	0	0	0
Payment of fees related to the term loan		0
Proceeds from term loan		0
Payment of principal related to capital leases	0	0	0
Common stock repurchases	0	0	0
Proceeds from senior secured notes			0
Proceeds from issuance of common stock	0	0	0
Excess tax benefits (detriments) from stock-based compensation	99	211	741
Net cash provided by (used in) financing activities	99	211	741
Effect of exchange rate fluctuations on cash and cash equivalents	(1,893)	(578)	(2,588)
Net increase (decrease) in cash and cash equivalents	116,772	7,686	49,687
Cash and cash equivalents, beginning of period	311,308	303,622	253,935
Cash and cash equivalents, end of period	428,080	311,308	303,622
Consolidation, Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	0	0	0
Purchases of short-term investments		0	0
Purchases of non-marketable minority equity investments			0
Proceeds from maturities and sale of short-term investments	0	0	0
Proceeds from sale of property			0
Proceeds from sale of subsidiary	0	0
Purchases of property and equipment	0	0	0
Net cash provided by (used in) investing activities	0	0	0
Payment of debt issuance costs related to the senior secured notes			0
Payment of principal related to the revolving credit facility			0
Payment of principal related to the convertible subordinated debt			0
Payment of principal related to the term loan	0	0	0
Payment of fees related to the term loan		0
Proceeds from term loan		0
Payment of principal related to capital leases	0	0	0
Common stock repurchases	0	0	0
Proceeds from senior secured notes			0
Proceeds from issuance of common stock	0	0	0
Excess tax benefits (detriments) from stock-based compensation	0	0	0
Net cash provided by (used in) financing activities	0	0	0
Effect of exchange rate fluctuations on cash and cash equivalents	0	0	0
Net increase (decrease) in cash and cash equivalents	0	0	0
Cash and cash equivalents, beginning of period	0	0	0
Cash and cash equivalents, end of period	$ 0	$ 0	$ 0