Discontinued Operations (Details) - Schedule Of Discontinued Items Statement of Operations $ in Thousands	3 Months Ended
	Apr. 30, 2021 USD ($)
Schedule Of Discontinued Items Statement of Operations [Abstract]
Net sales and revenue	$ 62	[1]
Cost of Sales	1,737
Gross loss	(1,675)
Selling, general and administrative	(85)
Loss before income taxes	(1,760)
Benefit for income taxes	2,195
Net income from discontinued operations, net of tax	435
Net loss attributable to noncontrolling interests	80
Net income (loss) attributable to REX common shareholders	$ 515

[1] Refined coal sales were recorded net of the cost of coal as the Company purchased the coal feedstock from the customer to which the processed refined coal was sold.