Document and Entity Information - USD ($)
12 Months Ended
Jun. 30, 2017
Aug. 21, 2017
Dec. 31, 2016
Document And Entity Information [Abstract]      
Entity Registrant Name ACETO CORP    
Entity Central Index Key 0000002034    
Trading Symbol acet    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Current Fiscal Year End Date --06-30    
Entity Filer Category Large Accelerated Filer    
Entity Well-known Seasoned Issuer No    
Entity Common Stock Shares Outstanding   30,109,417  
Entity Public Float     $ 564,677,707
Document Type 10-K/A    
Document Period End Date Jun. 30, 2017    
Amendment Flag false    
Document Fiscal Year Focus 2017    
Document Fiscal Period Focus FY