REAL ESTATE INVESTMENTS - 3025 JFK Venture (Narrative) (Details) $ in Thousands		12 Months Ended
	Feb. 02, 2021 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Feb. 02, 2021 a	Feb. 02, 2021 ft²
Schedule of Investments [Line Items]
Investment in real estate ventures, at equity		$ 552,494	$ 532,224
Net gain on sale of undepreciated real estate		$ 1,211	$ 8,007	$ 2,903
3025 JFK Boulevard
Schedule of Investments [Line Items]
Lease agreement term (in years)	99 years
Land area					1	1
Investment in real estate ventures, at equity	$ 34,800
Net gain on sale of undepreciated real estate	$ 2,000