EARNINGS PER SHARE ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC. (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Apr. 30, 2018	Apr. 30, 2017
EARNINGS PER SHARE ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC.
Net income attributable to the stockholders of Argan, Inc.	$ 4,837	$ 20,625
Weighted average number of shares outstanding - basic	15,568	15,467
Effect of stock options	88	304
Weighted average number of shares outstanding - diluted	15,656	15,771
Basic (in Dollars per share)	$ 0.31	$ 1.33
Diluted (in Dollars per share)	$ 0.31	$ 1.31