REAL ESTATE AND RELATED LEASE INTANGIBLES, NET - Unamortized Favorable Lease Intangibles (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Gross intangible assets	$ 161,203	$ 162,002
Accumulated amortization	62,773	57,712
Total	98,430	104,290
Unamortized favorable lease intangibles	4,500	5,500
Increase in operating lease income for amortization of below market lease intangibles acquired	2,177	2,387	$ 1,880
Above Market Leases
Business Acquisition [Line Items]
Reduction in operating lease income for amortization of above market lease intangibles acquired	$ (819)	$ (648)	$ (1,094)