Financing Arrangements (Details) (USD $)	3 Months Ended		6 Months Ended		34 Months Ended	36 Months Ended
	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2011	Jul. 31, 2010	Jun. 02, 2008	Jan. 31, 2011	May 12, 2011	Jul. 31, 2011 Park Creek Metropolitan District [Member]	Aug. 16, 2005 Park Creek Metropolitan District [Member]	Jul. 31, 2011 City Of Denver [Member]	Jun. 30, 2009 City Of Denver [Member]
Financing Commitments By Region [Line Items]
Amount Committed To Fund for infrastructure Projects								$ 24,500,000			$ 10,000,000
Amount funded for infrastructure projects								22,183,000		8,198,000
Junior Subordinated Bonds Issued									58,000,000
Interest Rate on Issuance of Junior Subordinated Bonds									8.50%
Notional amount of total rate of return swap contact amount					58,000,000
Fund Withdrawn from Trustee					58,000,000
Purchase of Converted bonds from investment banks						23,000,000
Fair value of converted bond in to other assets	16,000,000		16,000,000			58,000,000
Secured Debt related to converted bonds	16,000,000		16,000,000			35,000,000
Notes Receivable Owned by the Company used as collateral	6,154,000		6,154,000
Net Interest Income related to TRS	251,000	503,000	674,000	1,025,000
Outstanding junior subordinated bond							58,000,000
Refinanced junior subordinated bond							42,000,000
Proceeds as Repayment of convertible bond held by subsidiaries							23,000,000
Termination of TRS and Secured borrowings							$ 19,000,000