Segments and Entity-Wide Disclosures - Geographic Distribution of Equipment, Building, Furniture and Fixtures (Details) - USD ($) $ in Thousands	Jan. 31, 2018	Oct. 31, 2017
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, building, furniture and fixtures, net	$ 318,835	$ 308,465
Canada
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, building, furniture and fixtures, net	212,142	203,491
United States
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, building, furniture and fixtures, net	86,836	90,482
Other International
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, building, furniture and fixtures, net	$ 19,857	$ 14,492