Document and Entity Information	6 Months Ended
	Apr. 30, 2012	May 26, 2012
Document Information [Line Items]
Entity Registrant Name	CIENA CORP
Entity Central Index Key	0000936395
Current Fiscal Year End Date	--10-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Apr. 30, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		99,153,854
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes