Discontinued Operations and Gain on Disposition of Rental Properties Assets Held-for-sale (Details) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2012	Jan. 31, 2012
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total assets	$ 18,834	$ 0
Total Liabilities	15,092	0
Southfield [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real estate, net	18,478
Other assets	356
Total assets	18,834
Mortgage debt and notes payable, nonrecourse	14,914
Accounts Payable, accrued expenses and other liabilities	178
Total Liabilities	$ 15,092