SEGMENTS AND ENTITY WIDE DISCLOSURES (Details 2) $ in Thousands	3 Months Ended
	Jan. 31, 2017 USD ($) region	Jan. 31, 2016 USD ($)	Oct. 31, 2016 USD ($)
Segment Reporting [Abstract]
Number of geographic regions in which entity operates | region	4
Ciena's geographic distribution of revenue
Revenue	$ 621,497	$ 573,115
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, building, furniture and fixtures, net	293,150		$ 288,406
North America
Ciena's geographic distribution of revenue
Revenue	405,928	392,704
EMEA
Ciena's geographic distribution of revenue
Revenue	91,543	80,722
CALA
Ciena's geographic distribution of revenue
Revenue	35,146	43,810
APAC
Ciena's geographic distribution of revenue
Revenue	88,880	55,879
United States
Ciena's geographic distribution of revenue
Revenue	379,700	$ 365,200
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, building, furniture and fixtures, net	104,187		103,018
Canada
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, building, furniture and fixtures, net	178,391		173,885
Other International
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, building, furniture and fixtures, net	$ 10,572		$ 11,503