EARNINGS PER SHARE ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC. - Additional Information (Details) - shares	3 Months Ended		6 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2015	Jul. 31, 2014
EARNINGS PER SHARE ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC.
Additional shares included in the calculation of diluted EPS	256,000	256,000	258,000	291,000
Shares covered by antidilutive stock options	0	0	75,000	0