v3.5.0.2
Document and Entity Information - shares
6 Months Ended
Oct. 30, 2016
Dec. 02, 2016
Document and Entity Information [Abstract]    
Entity Registrant Name FINISAR CORP  
Entity Central Index Key 0001094739  
Current Fiscal Year End Date --04-30  
Entity Filer Category Large Accelerated Filer  
Document Type 10-Q  
Document Period End Date Oct. 30, 2016  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Entity Common Stock, Shares Outstanding   110,694,001