Ciena Corporation and Significant Accounting Policies and Estimates - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2020	Nov. 03, 2019	Nov. 02, 2019	Nov. 03, 2018	Nov. 01, 2017	Oct. 31, 2017
Significant Accounting Policies [Line Items]
Equity investments	$ 13,408		$ 10,727
Expected economic lives of finite-lived intangible assets (in years)	7 years
Expected number of years Spares usage cost is expensed	4 years
Cumulative amount of temporary differences for unremitted foreign earnings for which a deferred tax liability has not been recognized	$ 375,000
Stockholder's equity	$ 2,509,597		2,172,761	$ 1,929,334		$ 2,136,342
One-time employee termination benefits related to service period (in days)	60 days
Operating right-of-use assets	$ 57,026	$ 53,334
Operating lease liabilities	80,450	$ 76,000
Restructuring reserve	$ 2,915		15,143	3,847		2,939
Effect of adoption of new accounting standard
Significant Accounting Policies [Line Items]
Stockholder's equity				$ 49,805		62,123
Restructuring reserve			(11,160)
Facility Closing, Vacated Office Space
Significant Accounting Policies [Line Items]
Restructuring reserve			11,100
Minimum
Significant Accounting Policies [Line Items]
Payment terms and cash received	30 days
Maximum
Significant Accounting Policies [Line Items]
Payment terms and cash received	90 days
Foreign exchange contract maturities	24 months
Equipment, furniture and fixtures | Minimum
Significant Accounting Policies [Line Items]
Estimated useful lives capitalized and amortized straight-line (in years)	2 years
Equipment, furniture and fixtures | Maximum
Significant Accounting Policies [Line Items]
Estimated useful lives capitalized and amortized straight-line (in years)	5 years
Software and website development | Minimum
Significant Accounting Policies [Line Items]
Estimated useful lives capitalized and amortized straight-line (in years)	2 years
Software and website development | Maximum
Significant Accounting Policies [Line Items]
Estimated useful lives capitalized and amortized straight-line (in years)	5 years
3.75% Convertible Senior Notes due October 15, 2018 (New)
Significant Accounting Policies [Line Items]
Interest rate on convertible notes	3.75%			0.0375%
Retained Earnings
Significant Accounting Policies [Line Items]
Stockholder's equity	$ (4,283,122)		$ (4,644,413)	$ (4,947,652)		(4,664,253)
Retained Earnings | Effect of adoption of new accounting standard
Significant Accounting Policies [Line Items]
Stockholder's equity				$ 49,805		$ 61,291
Retained Earnings | Accounting Standards Update 2016-09 | Effect of adoption of new accounting standard
Significant Accounting Policies [Line Items]
Stockholder's equity					$ 62,100