v3.5.0.2
Document and Entity Information - USD ($)
12 Months Ended
Apr. 30, 2016
Jul. 11, 2016
Oct. 31, 2015
Document And Entity Information      
Entity Registrant Name PEREGRINE PHARMACEUTICALS INC    
Entity Central Index Key 0000704562    
Document Type 10-K    
Document Period End Date Apr. 30, 2016    
Amendment Flag false    
Current Fiscal Year End Date --04-30    
Is Entity a Well-known Seasoned Issuer? No    
Is Entity a Voluntary Filer? No    
Is Entity's Reporting Status Current? Yes    
Entity Filer Category Accelerated Filer    
Entity Public Float     $ 204,411,929
Entity Common Stock, Shares Outstanding   241,456,721  
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2016