Document and Entity Information - shares	6 Months Ended
	Dec. 31, 2017	Jan. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	ACETO CORP
Entity Central Index Key	0000002034
Trading Symbol	acet
Current Fiscal Year End Date	--06-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock Shares Outstanding		30,762,550
Document Type	10-Q
Document Period End Date	Dec. 31, 2017
Amendment Flag	false
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q2