REAL ESTATE AND RELATED LEASE INTANGIBLES, NET - Unamortized Favorable Lease Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Business Acquisition [Line Items]
Gross intangible assets	$ 159,721		$ 159,721		$ 162,002
Accumulated amortization	61,056		61,056		57,712
Net intangible assets	98,665		98,665		104,290
Increase in operating lease income for amortization of below market lease intangibles acquired	564	$ 500	1,594	$ 1,821
Unamortized favorable lease intangibles	4,600		4,600		$ 5,500
Above Market Leases
Business Acquisition [Line Items]
Reduction in operating lease income for amortization of above market lease intangibles acquired	$ (94)	$ (155)	$ (727)	$ (535)