Document and Entity Information (USD $)	6 Months Ended
	Jul. 31, 2011	Sep. 08, 2011	Jul. 31, 2010
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, 2011
Amendment Flag	false
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--01-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Smaller Reporting Company
Entity Public Float			$ 19,222,441
Entity Common Stock, Shares Outstanding		13,607,994