EARNINGS PER SHARE ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC. (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2016	Oct. 31, 2015
EARNINGS PER SHARE ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC.
Net income attributable to the stockholders of Argan, Inc.	$ 18,073	$ 10,807	$ 49,977	$ 29,617
Weighted average number of shares outstanding - basic	15,137	14,810	14,974	14,732
Effect of stock options	464	256	516	272
Weighted average number of shares outstanding - diluted	15,601	15,066	15,490	15,004
Basic (in Dollars per share)	$ 1.19	$ 0.73	$ 3.34	$ 2.01
Diluted (in Dollars per share)	$ 1.16	$ 0.72	$ 3.23	$ 1.97