CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
Income Statement [Abstract]
Net sales and revenue	$ 124,251	$ 86,671	$ 246,828	$ 297,114
Cost of sales (includes $16,861 and $58,536 with related parties for the quarters ended October 31, 2020 and 2019, respectively, and $34,021 and $148,743 with related parties for the nine months ended October 31, 2020 and 2019, respectively	106,572	88,429	239,810	291,222
Gross profit (loss)	17,679	(1,758)	7,018	5,892
Selling, general and administrative expenses (includes $(15) and $(242) with related parties for the quarters ended October 31, 2020 and 2019, respectively, and $(160) and $(577) with related parties for the nine months ended October 31, 2020 and 2019, respectively)	(4,257)	(4,133)	(13,300)	(13,629)
Equity in income (loss) of unconsolidated affiliates	1,152	(15)	168	350
Interest and other income, (net)	537	1,002	1,403	3,381
Income (loss) before income taxes	15,111	(4,904)	(4,711)	(4,006)
(Provision) benefit for income taxes	(4,052)	3,231	5,307	9,401
Net income (loss)	11,059	(1,673)	596	5,395
Net income attributable to noncontrolling interests	(2,218)	(379)	(1,138)	(2,370)
Net income (loss) attributable to REX common shareholders	$ 8,841	$ (2,052)	$ (542)	$ 3,025
Weighted average shares outstanding – basic and diluted (in Shares)	6,143	6,319	6,221	6,318
Basic and diluted net income (loss) per share attributable to REX common shareholders (in Dollars per share)	$ 1.44	$ (0.32)	$ (0.09)	$ 0.48