NET INCOME (LOSS) PER SHARE ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Apr. 30, 2021	Apr. 30, 2020
NET INCOME (LOSS) PER SHARE ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN
Net income (loss) attributable to the stockholders of Argan, Inc.	$ 10,766	$ (763)
Weighted average number of shares outstanding - basic	15,726	15,643
Effects of stock awards	235
Weighted average number of shares outstanding - diluted	15,961	15,643
Basic	$ 0.68	$ (0.05)
Diluted	$ 0.67	$ (0.05)