ACQUISITIONS AND DISPOSITIONS - Fair Value of Net Assets Acquired (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018 USD ($) property	Mar. 31, 2017 property	Dec. 31, 2017
Business Acquisition [Line Items]
Percent of total assets, less than	10.00%
Number of properties sold | property	0
Number of business acquisitions | property		0
Acquired in-place leases
Business Acquisition [Line Items]
Average useful life (in years)	7 years		9 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