Document And Entity Information (USD $)	12 Months Ended
	Oct. 27, 2012	Dec. 07, 2012	Apr. 28, 2012
Entity Information [Line Items]
Entity Registrant Name	BROCADE COMMUNICATIONS SYSTEMS INC
Entity Central Index Key	0001009626
Current Fiscal Year End Date	--10-27
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Oct. 27, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		456,174,616
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 2,521,950,135