Subsequent Event (Details) (USD $)	3 Months Ended			6 Months Ended		1 Months Ended
	Oct. 31, 2011	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2011	Jul. 31, 2010	Aug. 31, 2011 Subsequent Event [Member]	Jul. 31, 2011 Subsequent Event [Member]
Subsequent Event (Details Textual) [Abstract]
Area of land in acres under development Project							13
Non recouse mortgage under development Project							$ 41,800,000
Cash payment of nonrecourse mortgage						26,600,000
Gain (loss) on early extinguishment of debt	$ 15,200,000	$ (5,471,000)	$ 1,896,000	$ (5,767,000)	$ 8,193,000