Real Estate Fund Investments - Schedule of Financial Information for Fund Investment (Details) - Unconsolidated Real Estate Funds [Member] - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Property Fund II [Member]
Investment Holdings [Line Items]
Real estate investments	$ 11,134	$ 64,989
Cash and cash equivalents	931	1,297
Other assets	115	127
Total assets	12,180	66,413
Other liabilities	58	60
Total liabilities	58	60
Equity	12,122	66,353
Total liabilities and equity	12,180	66,413
Property Fund III [Member]
Investment Holdings [Line Items]
Real estate investments	19,697	39,376
Cash and cash equivalents	2,185	2,221
Total assets	21,882	41,597
Other liabilities	53	49
Total liabilities	53	49
Equity	21,829	41,548
Total liabilities and equity	21,882	41,597
Property Fund VII [Member]
Investment Holdings [Line Items]
Real estate investments	165,690	165,556
Cash and cash equivalents	878	741
Total assets	166,568	166,297
Other liabilities	1,967	1,483
Total liabilities	1,967	1,483
Equity	164,601	164,814
Total liabilities and equity	$ 166,568	$ 166,297