Agreements and Transactions with Related Parties - Related Party Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Amounts Included in the Consolidated Statements of Income
Asset management fees	$ 12,528	$ 11,914	$ 11,539
Available Cash Distributions	7,345	7,225	8,132
Personnel and overhead reimbursements	2,714	2,648	3,161
Interest expense	536	468	492
Disposition fees	0	0	1,117
Operating expenses	23,123	22,255	24,441
Acquisition Fees Capitalized
Capitalized personnel and overhead reimbursements	135	140	665
Current acquisition fees	0	110	695
Deferred acquisition fees	0	88	555
Transaction fees incurred	$ 135	$ 338	$ 1,915