INCOME PROPERTIES AND LEASES - Properties Acquired (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) ft²
Acquisitions of Income Properties
Square-Feet | ft²	522,681
Purchase price	$ 137,235
Remaining Lease Term	4 years 2 months 12 days
2020 acquisitions of income property subject to lease
Acquisitions of Income Properties
Purchase price	$ 137,200
Winston-Salem, NC | 2020 acquisitions of income property subject to lease
Acquisitions of Income Properties
Square-Feet | ft²	254,109
Purchase price	$ 61,800
Percentage Leased	99.00%
Remaining Lease Term	5 years
Falls Church, VA | 2020 acquisitions of income property subject to lease
Acquisitions of Income Properties
Square-Feet | ft²	268,572
Purchase price	$ 75,435
Percentage Leased	80.00%
Remaining Lease Term	3 years 7 months 6 days