Segment and Entity Wide Disclosures - Entity Wide Reporting (Details) $ in Thousands	12 Months Ended
	Oct. 31, 2020 USD ($) region	Nov. 02, 2019 USD ($)	Nov. 03, 2018 USD ($)
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of geographic regions | region	3
Ciena's geographic distribution of revenue
Revenues	$ 3,532,157	$ 3,572,131	$ 3,094,286
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, building, furniture and fixtures, net	329,403	286,884
Americas
Ciena's geographic distribution of revenue
Revenues	2,469,278	2,503,913	2,026,627
Canada
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, building, furniture and fixtures, net	214,188	211,901
United States
Ciena's geographic distribution of revenue
Revenues	2,250,000	2,250,000	1,770,000
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, building, furniture and fixtures, net	65,321	58,119
EMEA
Ciena's geographic distribution of revenue
Revenues	591,468	566,718	464,876
APAC
Ciena's geographic distribution of revenue
Revenues	471,411	501,500	$ 602,783
Other International
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, building, furniture and fixtures, net	$ 49,894	$ 16,864