INCOME PROPERTIES - Properties Acquired (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019 USD ($) a ft²
Acquisitions of Income Properties
Square-Feet | ft²	139,514
Purchase price	$ 40,559
Remaining Lease Term	9 years 6 months
2019 acquisitions of income property subject to lease
Acquisitions of Income Properties
Purchase price	$ 40,600
Winston-Salem, NC | 2019 acquisitions of income property subject to lease - Hobby Lobby Stores, Inc
Acquisitions of Income Properties
Square-Feet | ft²	55,000
Acres of land | a	7.63
Purchase price	$ 8,075
Percentage Leased	100.00%
Remaining Lease Term	10 years 10 months 24 days
Falls Church, VA | 2019 acquisitions of income property subject to lease - 24 Hour Fitness USA, Inc
Acquisitions of Income Properties
Square-Feet | ft²	46,000
Acres of land | a	3.09
Purchase price	$ 21,250
Percentage Leased	100.00%
Remaining Lease Term	8 years 7 months 6 days
Birmingham, AL | 2019 acquisitions of income property subject to lease - Walgreen Co.
Acquisitions of Income Properties
Square-Feet | ft²	14,516
Acres of land | a	2.05
Purchase price	$ 5,500
Percentage Leased	100.00%
Remaining Lease Term	9 years 9 months 18 days
Lynn, MA | 2019 acquisitions of income property subject to lease - Family Dollar Stores of Massachusetts, Inc
Acquisitions of Income Properties
Square-Feet | ft²	9,228
Acres of land | a	0.67
Purchase price	$ 2,100
Percentage Leased	100.00%
Remaining Lease Term	4 years 9 months 18 days
Albany, GA | 2019 acquisitions of income property subject to lease - Walgreen Co.
Acquisitions of Income Properties
Square-Feet | ft²	14,770
Acres of land | a	3.55
Purchase price	$ 3,634
Percentage Leased	100.00%
Remaining Lease Term	13 years 7 months 6 days