REAL ESTATE INVESTMENTS - Capitalized Construction Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Internal direct construction costs capitalized related to development of properties and land holdings	$ 7,431	$ 6,964	$ 6,063
Development
Property, Plant and Equipment [Line Items]
Internal direct construction costs capitalized related to development of properties and land holdings	3,047	3,185	4,390
Redevelopment
Property, Plant and Equipment [Line Items]
Internal direct construction costs capitalized related to development of properties and land holdings	775	968	319
Tenant Improvements
Property, Plant and Equipment [Line Items]
Internal direct construction costs capitalized related to development of properties and land holdings	$ 3,609	$ 2,811	$ 1,354