Document and Entity Information - shares	3 Months Ended
	Apr. 30, 2016	Jun. 06, 2016
Document And Entity Information
Entity Registrant Name	ARGAN INC
Entity Central Index Key	0000100591
Trading Symbol	AGX
Document Type	10-Q
Document Period End Date	Apr. 30, 2016
Amendment Flag	false
Current Fiscal Year End Date	--01-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		14,858,469
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q1