REAL ESTATE SOLD AND HELD FOR SALE DISCONTINUED OPERATIONS (Details)	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2019 USD ($) ft²	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($) a	Jun. 30, 2019 USD ($) ft²	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($) ft² Integer
Long Lived Assets Held-for-sale [Line Items]
Document Period End Date				Jun. 30, 2019
Gains (Losses) on Sales of Investment Real Estate	$ 9,081,000	$ 0		$ 11,406,000	$ 10,222,000
Number of real estate properties transferred to held for sale and sold | Integer						3
2019 Operating Property Sales [Member] [Domain]
Long Lived Assets Held-for-sale [Line Items]
Square Footage of Real Estate Property | ft²	237,000			237,000
Gain (Loss) on Sale of Properties				$ 11,400,000
Proceeds from Sale of Property, Plant, and Equipment				$ 18,700,000
Altamonte Commerce Center [Member]
Long Lived Assets Held-for-sale [Line Items]
Gain (Loss) on Sale of Properties	$ 9,100,000
2018 Operating Property Sales [Member]
Long Lived Assets Held-for-sale [Line Items]
Square Footage of Real Estate Property | ft²						339,000
Gain (Loss) on Sale of Properties						$ 14,300,000
Proceeds from Sale of Property, Plant, and Equipment						$ 22,900,000
Land [Member]
Long Lived Assets Held-for-sale [Line Items]
Size (in acres) of land sold | a			11
Proceeds from Sale of Property, Plant, and Equipment			$ 2,600,000
Gain on sales of land			$ 86,000