TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities [Line Items]
Amortization expense	$ 20,236	$ 20,405	$ 14,429
Housing Subsidy Intangible Asset
Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities [Line Items]
Remaining amortization period	28 years 8 months 12 days
Amortization expense	$ 100	100	100
Property Tax Abatement Intangible Asset
Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities [Line Items]
Amortization expense	$ 500	500	$ 100
Property Tax Abatement Intangible Asset | Minimum
Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities [Line Items]
Intangible asset, amortization	3 years 9 months 18 days
Prepaid Expenses and Other Assets
Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities [Line Items]
Intangible assets, net	$ 2,300	2,400
Unamortized tax abatement intangible asset	$ 1,800	$ 2,300