Segment Reporting (Details) - Schedule of Segment Reporting Information, Profit Loss and Revenue Percentage (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2013	Oct. 31, 2012
Segment Reporting (Details) - Schedule of Segment Reporting Information, Profit Loss and Revenue Percentage [Line Items]
Net sales and revenue	$ 166,505	$ 178,849	$ 520,867	$ 482,912
Gross profit	18,178	3,741	38,258	16,203
Income from continuing operations before income taxes	15,998	979	32,365	4,543
Alternative Energy Segment [Member] | Ethanol [Member]
Segment Reporting (Details) - Schedule of Segment Reporting Information, Profit Loss and Revenue Percentage [Line Items]
Sale of Product	76.00%	74.00%	75.00%	76.00%
Alternative Energy Segment [Member] | Dried Distillers Grains [Member]
Segment Reporting (Details) - Schedule of Segment Reporting Information, Profit Loss and Revenue Percentage [Line Items]
Sale of Product	19.00%	19.00%	18.00%	18.00%
Alternative Energy Segment [Member] | Modified Distillers Grains [Member]
Segment Reporting (Details) - Schedule of Segment Reporting Information, Profit Loss and Revenue Percentage [Line Items]
Sale of Product	2.00%	4.00%	4.00%	3.00%
Alternative Energy Segment [Member] | Other Products [Member]
Segment Reporting (Details) - Schedule of Segment Reporting Information, Profit Loss and Revenue Percentage [Line Items]
Sale of Product	3.00%	3.00%	3.00%	3.00%
Alternative Energy Segment [Member]
Segment Reporting (Details) - Schedule of Segment Reporting Information, Profit Loss and Revenue Percentage [Line Items]
Net sales and revenue	166,039	178,495	519,653	481,938
Gross profit	18,002	3,686	37,918	16,224
Income from continuing operations before income taxes	16,491	1,586	34,231	6,478
Sale of Product	100.00%	100.00%	100.00%	100.00%
Real Estate Segment [Member]
Segment Reporting (Details) - Schedule of Segment Reporting Information, Profit Loss and Revenue Percentage [Line Items]
Net sales and revenue	466	354	1,214	974
Gross profit	176	55	340	(21)
Income from continuing operations before income taxes	115	(6)	157	(218)
Lease revenue	100.00%	100.00%	100.00%	100.00%
Corporate Segment [Member]
Segment Reporting (Details) - Schedule of Segment Reporting Information, Profit Loss and Revenue Percentage [Line Items]
Income from continuing operations before income taxes	$ (608)	$ (601)	$ (2,023)	$ (1,717)