Investments in Unconsolidated Real Estate Funds - Schedule of Financial Information for Fund Investment (Details) - Unconsolidated Real Estate Funds [Member] - Property Fund VII [Member] - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Investment Holdings [Line Items]
Real estate investments	$ 31,352	$ 32,943
Cash and cash equivalents	1,935	138
Total assets	33,287	33,081
Other liabilities	1,076	1,058
Total liabilities	1,076	1,058
Equity	32,211	32,023
Total liabilities and equity	$ 33,287	$ 33,081