BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES - Revenue (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Accounting Policies [Abstract]
Fixed lease income - operating leases	$ 60,324,000	$ 60,851,000	$ 184,256,000	$ 176,911,000
Variable lease income - operating leases	3,006,000	2,905,000	9,523,000	7,728,000
Other property revenue	1,238,000	1,682,000	3,462,000	4,229,000
Total revenue	64,568,000	65,438,000	197,241,000	188,868,000
Gain on sale of real estate and other investments	$ 11,235,000	$ 0	$ 71,327,000	$ 27,000