Notes and Accounts Receivable Net (Details Textual) (Stapleton advances [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011
Stapleton advances [Member]
Notes and Accounts Receivable, Net (Textual) [Abstract]
Interest Income Related to Infrastructure Advances to the Park Creek Metropolitan District	$ 7,893	$ 6,439	$ 4,237
Weighted Average Interest Rate of Infrastructure Advances to the Park Creek Metropolitan District	8.70%