Investments in and Advances to Unconsolidated Affiliates - Schedule of Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Aug. 08, 2019
Schedule of Equity Method Investments [Line Items]
Due from (to) Related Parties	$ 666	$ 363
Other	3,811	1,881
Investments in and advances to unconsolidated affiliates	322,326	272,829
Distributions in excess of income from, and investments in, unconsolidated affiliates	$ 9,939	15,616
KLA/ABS
Schedule of Equity Method Investments [Line Items]
Cost method investment, ownership percentage	36.70%
Cost Method Investment	$ 124,316	72,391
Self Storage Management
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	95.00%
Equity method investments	$ 207	207
640 Broadway
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	63.13%
Equity method investments	$ 17,825	17,457
Fund III
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 18,032	17,664
Fund IV Other Portfolio
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	98.57%
Equity method investments	$ 12,675	11,719
650 Bald Hill Road
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	90.00%
Equity method investments	$ 11,677	12,550
Paramus Plaza
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	50.00%
Equity method investments	$ 1,975	5,565
Fund IV
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 26,327	29,834
Fund V Family Center at Riverdale
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	89.42%
Equity method investments	$ 12,449	11,824
Tri City Plaza
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	90.00%
Equity method investments	$ 6,827	7,024
Frederick County Acquisitions
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	90.00%
Equity method investments	$ 10,748	10,837
Fund V
Schedule of Equity Method Investments [Line Items]
Equity method investments	30,024	29,685
Core Portfolio
Schedule of Equity Method Investments [Line Items]
Equity method investments	119,150	121,011	$ 200	$ 1,800
Other	$ 3,700
Core Portfolio | 840 N. Michigan
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	88.43%
Equity method investments	$ 51,513	55,863
Core Portfolio | Renaissance Portfolio
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	20.00%
Equity method investments	$ 28,466	29,270
Core Portfolio | Gotham Plaza
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	49.00%
Equity method investments	$ 29,187	28,683
Core Portfolio | Georgetown Portfolio
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	50.00%
Equity method investments	$ 4,089	4,624
Core Portfolio | 1238 Wisconsin Avenue
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	80.00%
Equity method investments	$ 5,895	2,571
Core Portfolio | Crossroads
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	49.00%
Distributions in excess of income from, and investments in, unconsolidated affiliates	$ 9,939	$ 15,616