Document And Entity Information	6 Months Ended
	Apr. 28, 2012	May 25, 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-Q
Document Period End Date	Apr. 28, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		450,066,045