Ciena Corporation and Significant Accounting Policies and Estimates - Cumulative Effect of the Changes Made to Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Nov. 01, 2018	Oct. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	$ 724,854	$ 799,011	$ 786,502
Inventories	345,049	260,265	262,751
Prepaid expenses and other	297,914	220,415	198,945
Deferred tax asset, net	714,942	730,600	745,039
Other long-term assets	88,986	75,650	71,652
Total assets	3,893,346	3,777,575	3,756,523
Deferred revenue	111,381	96,731	111,134
Long-term deferred revenue	45,492	43,973	58,323
Accumulated deficit	(4,644,413)	(4,897,847)	(4,947,652)
Total liabilities and stockholders’ equity	3,893,346	3,777,575	3,756,523
Capitalized contract acquisition costs	11,677		0
Capitalized acquisition costs, long term	$ 3,994		$ 0
Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net		12,509
Inventories		(2,486)
Prepaid expenses and other		21,470
Deferred tax asset, net		(14,439)
Other long-term assets		3,998
Total assets		21,052
Deferred revenue		(14,403)
Long-term deferred revenue		(14,350)
Accumulated deficit		49,805
Total liabilities and stockholders’ equity		21,052
Installation | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Unbilled receivables		27,500
Products | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Unbilled receivables		3,900
Multiple Element Software Arrangements | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred revenue		(23,600)
Long-term deferred revenue		(18,600)
Product Sales Other Than Multiple Element Software Arrangements | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred revenue		(1,700)
Maintenance Services Other Than Multiple Element Software Arrangements | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred revenue		2,700
Products and Services With Unpaid Invoices | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred revenue		8,200
Long-term deferred revenue		4,300
Capitalized Contract Acquisition Costs | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Capitalized contract acquisition costs		9,600
Capitalized acquisition costs, long term		4,000
Prepaid Costs of Installation Services | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Capitalized contract acquisition costs		$ (19,500)