Agreements and Transactions with Related Parties - Related Party Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Amounts Included in the Condensed Consolidated Statements of Operations
Asset management fees	$ 2,978	$ 2,929	$ 8,858	$ 8,656
Available Cash Distributions	1,168	1,619	5,113	5,572
Personnel and overhead reimbursements	696	1,080	2,027	2,661
Interest expense on deferred acquisition fees and external joint venture loans	116	128	371	383
Disposition fees	0	0	0	1,117
Operating expenses	4,958	5,756	16,369	18,389
Acquisition Fees Capitalized
Capitalized personnel and overhead reimbursements	26	2	96	91
Current acquisition fees	0	0	110	695
Deferred acquisition fees	0	0	88	555
Transaction fees incurred	$ 26	$ 2	$ 294	$ 1,341