REAL ESTATE SOLD AND HELD FOR SALE DISCONTINUED OPERATIONS (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2019 USD ($) ft²	Dec. 31, 2019 USD ($) ft² a
2019 Operating Property Sales [Member] [Domain]
Long Lived Assets Held-for-sale [Line Items]
Square Footage of Real Estate Property | ft²		617,000
Proceeds from Sale of Property, Plant, and Equipment		$ 68,500,000
Gain (Loss) on Sale of Properties		41,100,000
2Q19 Operating Property Sales - World Houston 5 and Altamonte Commerce Center [Member]
Long Lived Assets Held-for-sale [Line Items]
Square Footage of Real Estate Property | ft²	237,000
Proceeds from Sale of Property, Plant, and Equipment	$ 18,700,000
Gain (Loss) on Sale of Properties	$ 11,400,000
Land [Member]
Long Lived Assets Held-for-sale [Line Items]
Proceeds from Sale of Property, Plant, and Equipment		$ 185,000
Size (in acres) of land sold | a		0.2
Gain on sales of land		$ 83,000