Segment and Entity Wide Disclosures (Details 1) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2011	Jul. 31, 2010	Oct. 31, 2010
Ciena's geographic distribution of revenue
Revenue	$ 435,313	$ 389,675	$ 1,286,515	$ 819,022
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, furniture and fixtures, net	126,174		126,174		120,294
Customers accounting for at least 10% of Ciena's revenue
Revenue	75,068	131,325	333,730	204,092
United States [Member]
Ciena's geographic distribution of revenue
Revenue	227,524	229,739	678,674	534,174
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, furniture and fixtures, net	64,624		64,624		63,675
Canada [Member]
Ciena's geographic distribution of revenue
Revenue	43,815	22,840	128,770	65,125
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, furniture and fixtures, net	47,424		47,424		45,103
Other International [Member]
Ciena's geographic distribution of revenue
Revenue	163,974	137,096	479,071	219,723
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, furniture and fixtures, net	14,126		14,126		11,516
Company A [Member]
Customers accounting for at least 10% of Ciena's revenue
Revenue	75,068	90,769	202,009	204,092
Company B [Member]
Customers accounting for at least 10% of Ciena's revenue
Revenue		$ 40,556	$ 131,721