Earnings (Loss) Per Share Attributable to the Stockholders of Argan, Inc (Details) (USD $)	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012
Net Income (Loss) Per Share (Textual) [Abstract]
Weighted average number of dilutive common stock equivalent shares	330,000	180,000
Shares covered by antidilutive stock options	404,000	556,000
Operating losses associated with moxie project entities	$ 1,448,000	$ 302,000