Preferred Equity Investments and Investments in Unconsolidated Real Estate Joint Ventures (Details 1) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Preferred returns and equity in income of unconsolidated joint ventures	$ 10,312	$ 10,336	$ 11,632
Alexan CityCentre [Member]
Schedule of Equity Method Investments [Line Items]
Preferred returns and equity in income of unconsolidated joint ventures	1,668	1,395	1,085
Alexan Southside Place [Member]
Schedule of Equity Method Investments [Line Items]
Preferred returns and equity in income of unconsolidated joint ventures	3,201	2,879	2,605
Arlo [Member]
Schedule of Equity Method Investments [Line Items]
Preferred returns and equity in income of unconsolidated joint ventures	0	0	677
Cade Boca Raton [Member]
Schedule of Equity Method Investments [Line Items]
Preferred returns and equity in income of unconsolidated joint ventures	0	0	226
Domain at The One Forty [Member]
Schedule of Equity Method Investments [Line Items]
Preferred returns and equity in income of unconsolidated joint ventures	0	141	614
Flagler Village [Member]
Schedule of Equity Method Investments [Line Items]
Preferred returns and equity in income of unconsolidated joint ventures	0	(7)	(6)
Helios [Member]
Schedule of Equity Method Investments [Line Items]
Preferred returns and equity in income of unconsolidated joint ventures	2,459	2,454	2,461
Leigh House [Member]
Schedule of Equity Method Investments [Line Items]
Preferred returns and equity in income of unconsolidated joint ventures	1,910	1,770	1,492
North Creek Apartments [Member]
Schedule of Equity Method Investments [Line Items]
Preferred returns and equity in income of unconsolidated joint ventures	108	0	0
Other [Member]
Schedule of Equity Method Investments [Line Items]
Preferred returns and equity in income of unconsolidated joint ventures	0	(26)	530
Riverside Apartments [Member]
Schedule of Equity Method Investments [Line Items]
Preferred returns and equity in income of unconsolidated joint ventures	31	0	0
Whetstone Apartments [Member]
Schedule of Equity Method Investments [Line Items]
Preferred returns and equity in income of unconsolidated joint ventures	$ 935	$ 1,730	$ 1,948