Segment Reporting (Details) - Schedule Of Segment Results And Assets - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Segment Reporting Information [Line Items]
Net sales and revenue:		$ 105,868	$ 128,757	$ 210,443	$ 249,577
Segment gross profit (loss):		4,004	9,399	7,650	20,250
Income (loss) before income taxes:		731	4,859	898	12,508
Benefit (provision) for income taxes:		2,622	5,631	6,170	8,334
Segment profit (loss) (net of noncontrolling interests):		2,256	9,217	5,077	18,713
Sales of products, ethanol and by-products segment:		105,770	128,491	210,223	249,171
Ethanol [Member]
Segment Reporting Information [Line Items]
Net sales and revenue:		105,770	128,491	210,223	249,171
Segment gross profit (loss):		6,169	13,669	12,284	27,215
Income (loss) before income taxes:		3,111	10,077	6,313	21,086
Benefit (provision) for income taxes:		(619)	(2,029)	(1,105)	(3,449)
Segment profit (loss) (net of noncontrolling interests):		1,305	6,561	3,014	15,150
Sales of products, ethanol and by-products segment:		83,219	100,289	160,837	192,182
Refined Coal [Member]
Segment Reporting Information [Line Items]
Net sales and revenue:	[1]	98	266	220	406
Segment gross profit (loss):		(2,165)	(4,270)	(4,634)	(6,965)
Income (loss) before income taxes:		(2,028)	(4,788)	(4,703)	(7,647)
Benefit (provision) for income taxes:		3,155	7,597	7,101	11,596
Segment profit (loss) (net of noncontrolling interests):		1,216	3,018	2,602	4,289
Sales of products, ethanol and by-products segment:		98	266	220	406
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Income (loss) before income taxes:		(352)	(430)	(712)	(931)
Benefit (provision) for income taxes:		86	63	174	187
Segment profit (loss) (net of noncontrolling interests):		(265)	(362)	(539)	(726)
Dried Distillers Grains [Member]
Segment Reporting Information [Line Items]
Sales of products, ethanol and by-products segment:		15,887	21,059	34,561	41,143
Non-Food Grade Corn Oil [Member]
Segment Reporting Information [Line Items]
Sales of products, ethanol and by-products segment:		4,599	5,075	9,582	10,055
Modified Distillers Grains [Member]
Segment Reporting Information [Line Items]
Sales of products, ethanol and by-products segment:		2,004	2,043	5,144	5,760
Other Segments [Member]
Segment Reporting Information [Line Items]
Sales of products, ethanol and by-products segment:		$ 61	$ 25	$ 99	$ 31

[1] The Company records sales in the refined coal segment net of the cost of coal as the Company purchases the coal feedstock from the customer to which refined coal is sold.