ACQUISITIONS AND DISPOSITIONS - Fair Value of Net Assets Acquired (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Business Acquisition [Line Items]
Percent of total assets, less than		10.00%
Acquired in-place leases
Business Acquisition [Line Items]
Average useful life (in years)	8 years		8 years
2018 Acquisitions
Business Acquisition [Line Items]
Net assets acquired		$ 132,048
2018 Acquisitions | Land
Business Acquisition [Line Items]
Property, plant, and equipment		52,199
2018 Acquisitions | Land improvements
Business Acquisition [Line Items]
Property, plant, and equipment		756
2018 Acquisitions | Buildings and improvements
Business Acquisition [Line Items]
Property, plant, and equipment		74,522
2018 Acquisitions | Tenant improvements
Business Acquisition [Line Items]
Property, plant, and equipment		1,451
2018 Acquisitions | Acquired in-place leases
Business Acquisition [Line Items]
Intangible assets		$ 7,003
Average useful life (in years)		3 years
2018 Acquisitions | Acquired above-market leases
Business Acquisition [Line Items]
Intangible assets		$ 109
Average useful life (in years)		2 years
2018 Acquisitions | Acquired below-market leases
Business Acquisition [Line Items]
Intangible assets		$ 3,992
Average useful life (in years)		3 years