Preferred Equity Investments and Investments in Unconsolidated Real Estate Joint Ventures (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 25, 2021	Dec. 31, 2020
Preferred Equity Investments and Investments in Unconsolidated Real Estate Joint Ventures
Total	$ 66,189		$ 99,638
Provision for credit losses	(315)		(16,153)
Total, net	65,874		83,485
Alexan CityCentre [Member]
Preferred Equity Investments and Investments in Unconsolidated Real Estate Joint Ventures
Total	15,725		15,063
Alexan Southside Place
Preferred Equity Investments and Investments in Unconsolidated Real Estate Joint Ventures
Total			26,038
Total, net		$ 10,100
Mira Vista [Member]
Preferred Equity Investments and Investments in Unconsolidated Real Estate Joint Ventures
Total	5,250		5,250
Strategic Portfolio [Member]
Preferred Equity Investments and Investments in Unconsolidated Real Estate Joint Ventures
Total	27,054		27,054
The Riley
Preferred Equity Investments and Investments in Unconsolidated Real Estate Joint Ventures
Total	6,961
The Conley
Preferred Equity Investments and Investments in Unconsolidated Real Estate Joint Ventures
Total			15,036
Thornton Flats [Member]
Preferred Equity Investments and Investments in Unconsolidated Real Estate Joint Ventures
Total	4,600		4,600
Wayforth at Concord [Member]
Preferred Equity Investments and Investments in Unconsolidated Real Estate Joint Ventures
Total	6,500		6,500
Other Property [Member]
Preferred Equity Investments and Investments in Unconsolidated Real Estate Joint Ventures
Total	$ 99		$ 97