Guarantor And Non-Guarantor Subsidiaries (Schedule Of Consolidated Statement Of Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Oct. 29, 2011	Oct. 30, 2010	Oct. 31, 2009
Net cash provided by operating activities	$ 449,232	$ 298,513	$ 115,562
Purchases of short-term investments	(38)	(53)	(138)
Purchases of non-marketable minority equity investments		(200)
Proceeds from maturities and sale of short-term investments	1,604	3,255	155,986
Proceeds from maturities and sale of long-term investments			30,173
Proceeds from sale of property		30,185
Purchases of property and equipment	(96,797)	(201,621)	(162,770)
Decrease in restricted cash			1,075,079
Proceeds from sale of subsidiary	3,905
Net cash paid in connection with acquisitions			(1,297,482)
Net cash provided by (used in) investing activities	(91,326)	(168,434)	(199,152)
Payment of debt issuance costs related to the senior secured notes		(3,666)
Payment of principal related to the term loan	(359,898)	(583,029)	(166,022)
Payment of fees related to the term loan	(1,167)		(30,525)
Proceeds from (payment of principal related to) the revolving credit facility		(14,050)	14,050
Payment of principal related to the convertible subordinated debt		(172,500)
Proceeds from term loan	198,950
Payment of principal related to capital leases	(1,761)	(1,173)
Common stock repurchases	(210,698)	(25,004)
Proceeds from Senior Secured Notes		587,968
Proceeds from issuance of common stock	97,152	81,593	145,655
Excess tax benefits or detriments from stock-based compensation	312	2,161	(832)
Net cash provided by (used in) financing activities	(277,110)	(127,700)	(37,674)
Effect of exchange rate fluctuations on cash and cash equivalents	(578)	(2,588)	1,573
Net increase (decrease) in cash and cash equivalents	80,218	(209)	(119,691)
Cash and cash equivalents, beginning of year	333,984	334,193	453,884
Cash and cash equivalents, end of year	414,202	333,984	334,193
Brocade Communications Systems, Inc. [Member]
Net cash provided by operating activities	436,714	71,094	126,497
Purchases of non-marketable minority equity investments		(200)
Proceeds from maturities and sale of short-term investments			101,083
Proceeds from maturities and sale of long-term investments			18,115
Proceeds from sale of property		30,185
Purchases of property and equipment	(86,447)	(196,193)	(153,186)
Decrease in restricted cash			1,075,079
Proceeds from sale of subsidiary	4,966
Net cash paid in connection with acquisitions			(1,297,482)
Net cash provided by (used in) investing activities	(81,481)	(166,208)	(256,391)
Payment of debt issuance costs related to the senior secured notes		(3,666)
Payment of principal related to the term loan	(359,898)	(583,029)	(166,022)
Payment of fees related to the term loan	(1,167)		(30,525)
Proceeds from (payment of principal related to) the revolving credit facility		(14,050)	14,050
Proceeds from term loan	198,950
Payment of principal related to capital leases	(1,761)	(1,173)
Common stock repurchases	(210,698)	(25,004)
Proceeds from Senior Secured Notes		587,968
Proceeds from issuance of common stock	97,152	81,593	145,655
Excess tax benefits or detriments from stock-based compensation	101	1,420	(832)
Net cash provided by (used in) financing activities	(277,321)	44,059	(37,674)
Net increase (decrease) in cash and cash equivalents	77,912	(51,055)	(167,568)
Cash and cash equivalents, beginning of year	23,455	74,510	242,078
Cash and cash equivalents, end of year	101,367	23,455	74,510
Subsidiary Guarantors [Member]
Net cash provided by operating activities	(5,851)	169,986	(465)
Purchases of short-term investments	(38)	(53)	(138)
Proceeds from maturities and sale of short-term investments	1,604	3,255	149
Purchases of property and equipment	(33)	471	(2,464)
Proceeds from sale of subsidiary	(1,061)
Net cash provided by (used in) investing activities	472	3,673	(2,453)
Payment of principal related to the convertible subordinated debt		(172,500)
Net cash provided by (used in) financing activities		(172,500)
Net increase (decrease) in cash and cash equivalents	(5,379)	1,159	(2,918)
Cash and cash equivalents, beginning of year	6,907	5,748	8,666
Cash and cash equivalents, end of year	1,528	6,907	5,748
Foreign Non-Guarantor Subsidiaries [Member]
Net cash provided by operating activities	18,369	57,433	(10,470)
Proceeds from maturities and sale of short-term investments			54,754
Proceeds from maturities and sale of long-term investments			12,058
Purchases of property and equipment	(10,317)	(5,899)	(7,120)
Net cash provided by (used in) investing activities	(10,317)	(5,899)	59,692
Excess tax benefits or detriments from stock-based compensation	211	741
Net cash provided by (used in) financing activities	211	741
Effect of exchange rate fluctuations on cash and cash equivalents	(578)	(2,588)	1,573
Net increase (decrease) in cash and cash equivalents	7,685	49,687	50,795
Cash and cash equivalents, beginning of year	303,622	253,935	203,140
Cash and cash equivalents, end of year	$ 311,307	$ 303,622	$ 253,935