Segment Reporting (Details) - Schedule of Segment Reporting Information, Profit Loss And Revenue Percentage (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
Segment Reporting (Details) - Schedule of Segment Reporting Information, Profit Loss And Revenue Percentage [Line Items]
Net sales and revenues	$ 150,231	$ 175,389	$ 306,167	$ 353,813
Segment gross profit (loss)	38,818	10,878	75,443	19,876
Segment profit (loss)	40,720	10,318	78,827	16,164
Alternative Energy Segment [Member]
Segment Reporting (Details) - Schedule of Segment Reporting Information, Profit Loss And Revenue Percentage [Line Items]
Net sales and revenues	150,133	175,290	305,960	353,614
Segment gross profit (loss)	38,820	10,890	75,434	19,916
Segment profit (loss)	41,509	11,114	80,385	17,740
Real Estate Segment [Member]
Segment Reporting (Details) - Schedule of Segment Reporting Information, Profit Loss And Revenue Percentage [Line Items]
Net sales and revenues	98	99	207	199
Segment gross profit (loss)	(2)	(12)	9	(40)
Segment profit (loss)	(28)	(74)	(44)	(163)
Corporate Segment [Member]
Segment Reporting (Details) - Schedule of Segment Reporting Information, Profit Loss And Revenue Percentage [Line Items]
Segment profit (loss)	$ (761)	$ (722)	$ (1,514)	$ (1,413)