Document and Entity Information	6 Months Ended
	Jul. 31, 2012	Sep. 07, 2012
Document and Entity Information [Abstract]
Entity Registrant Name	ARGAN INC
Entity Central Index Key	0000100591
Document Type	10-Q
Document Period End Date	Jul. 31, 2012
Amendment Flag	false
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--01-31
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		13,773,365