INCOME PROPERTIES AND LEASES (Details)		6 Months Ended
	May 23, 2019 USD ($) ft²	Jun. 30, 2019 USD ($) ft² building property	Jun. 30, 2018 USD ($) property	Jun. 24, 2019 USD ($) ft²	Feb. 21, 2019 USD ($) ft²	Dec. 31, 2018 property	Mar. 26, 2018 USD ($)
Acquisitions of Income Properties
Number of real estate properties | property						4
Payments to Acquire Commercial Real Estate		$ 40,559,000
Area of real estate property | ft²		139,514
Daytona Beach, FL
Acquisitions of Income Properties
Sales price							$ 11,400,000
2019 acquisitions of income property subject to lease
Acquisitions of Income Properties
Number of real estate properties | property		5
Payments to Acquire Commercial Real Estate		$ 40,600,000
Aggregate acquisition cost including capitalized acquisition costs		$ 40,900,000
Amount allocated of total acquisition cost
Weighted average amortization period of intangible assets		9 years 6 months
Weighted average amortization period of intangible liabilities		9 years 6 months
2019 acquisitions of income property subject to lease | Nonrecurring basis
Acquisitions of Income Properties
Land		$ 16,300,000
Buildings and improvements		20,500,000
Intangible assets pertaining to the in-place lease value, leasing fees and above market lease value		4,400,000
Intangible liabilities for below market lease value		$ 300,000
2018 acquisitions of income property subject to a lease
Acquisitions of Income Properties
Number of real estate properties | property			1
Payments to Acquire Commercial Real Estate			$ 28,000,000
Aggregate acquisition cost including capitalized acquisition costs			$ 29,000,000
Amount allocated of total acquisition cost
Weighted average amortization period of intangible assets			20 years
Weighted average amortization period of intangible liabilities			20 years
2018 acquisitions of income property subject to a lease | Nonrecurring basis
Acquisitions of Income Properties
Land			$ 12,000,000
Buildings and improvements			15,000,000
Intangible assets pertaining to the in-place lease value, leasing fees and above market lease value			2,800,000
Intangible liabilities for below market lease value			$ 800,000
Concierge Office Building
Acquisitions of Income Properties
Area of real estate property | ft²		22,012
Williamson Business Park office building
Acquisitions of Income Properties
Area of real estate property | ft²		15,360
Gain on Sale		$ 3,700,000
Gain on sale of properties (in dollars per share)		$ 0.49
Area of real estate property leased | ft²		7,600
Lease term		5 years
Mason Commerce Center
Acquisitions of Income Properties
Area of real estate property | ft²		30,720
Number of office building | building		2
Whole Foods | Sarasota, FL | Sold
Acquisitions of Income Properties
Sales price					$ 24,620,000
Area of real estate property | ft²					59,000
Gain on Sale		$ 6,900,000
Gain on sale of properties (in dollars per share)		0.96
3600 Peterson | Santa Clara, CA | Sold
Acquisitions of Income Properties
Sales price				$ 37,000,000
Area of real estate property | ft²				76,000
Gain on Sale		9,000,000
Gain on sale of properties (in dollars per share)		1.36
The Grove | Winter Park, FL | Sold
Acquisitions of Income Properties
Sales price	$ 18,250,000
Gain on Sale		2,800,000
Gain on sale of properties (in dollars per share)		$ 0.42
Area of real estate property leased | ft²	112,000