Document and Entity Information	9 Months Ended
	Jun. 30, 2012	Jul. 31, 2012
Document And Entity Information [Abstract]
Entity Registrant Name	AMERICAN PACIFIC CORP
Entity Central Index Key	0000350832
Document Type	10-Q
Document Period End Date	Jun. 30, 2012
Amendment Flag	false
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--09-30
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		7,622,591