NET INCOME (LOSS) 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, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
NET INCOME (LOSS) PER SHARE ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC.
Net income (loss) attributable to the stockholders of Argan, Inc.	$ 9,454	$ (6,855)	$ 14,300	$ (35,501)
Weighted average number of shares outstanding - basic	15,680	15,633	15,659	15,617
Effects of stock awards	153		136
Weighted average number of shares outstanding - diluted	15,833	15,633	15,795	15,617
Basic (in Dollars per share)	$ 0.60	$ (0.44)	$ 0.91	$ (2.27)
Diluted (in Dollars per share)	$ 0.60	$ (0.44)	$ 0.91	$ (2.27)