Ciena Corporation and Significant Accounting Policies and Estimates - Impact of Adopting ASC 606 on Condensed Consolidated Statement of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue	$ 3,572,131	$ 3,094,286	$ 2,801,687
Total cost of goods sold	2,030,065	1,779,596	1,555,901
Net income	$ 253,434	$ (344,690)	$ 1,261,953
Diluted net income (loss) per potential common share (in dollars per share)	$ 1.61	$ (2.49)	$ 7.53
Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue	$ (28,838)
Total cost of goods sold	(21,330)
Net income	$ (7,776)
Diluted net income (loss) per potential common share (in dollars per share)	$ (0.05)
Balances without adoption of ASC 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue	$ 3,543,293
Total cost of goods sold	2,008,735
Net income	$ 245,658
Diluted net income (loss) per potential common share (in dollars per share)	$ 1.56