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Commitments and Contingencies (Details 1) (Ministry of Finance, India, USD $)
In Millions, unless otherwise specified
3 Months Ended
Jan. 31, 2015
Oct. 31, 2014
Income Tax Examination [Line Items]    
Accrued liabilities related to contingencies $ 1.1us-gaap_IncomeTaxExaminationPenaltiesAndInterestAccrued $ 1.1us-gaap_IncomeTaxExaminationPenaltiesAndInterestAccrued
Maximum    
Income Tax Examination [Line Items]    
Estimate of possible loss $ 5.5us-gaap_IncomeTaxExaminationEstimateOfPossibleLoss
/ us-gaap_IncomeTaxAuthorityAxis
= cien_MinistryofFinanceIndiaMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember