EARNINGS PER SHARE ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC. (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015
EARNINGS PER SHARE ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC.
Net income attributable to the stockholders of Argan, Inc.	$ 19,674	$ 11,307	$ 31,904	$ 18,810
Weighted average number of shares outstanding - basic	14,939	14,747	14,899	14,693
Effect of stock options	339	256	332	259
Weighted average number of shares outstanding - diluted	15,278	15,003	15,231	14,952
Basic (in Dollars per share)	$ 1.32	$ 0.77	$ 2.14	$ 1.28
Diluted (in Dollars per share)	$ 1.29	$ 0.75	$ 2.09	$ 1.26