NOTES PAYABLE Narrative (Details)	Feb. 27, 2018 USD ($) Property extension_option	Sep. 30, 2020 USD ($) Property	Dec. 31, 2019 USD ($)	Sep. 30, 2019 Property
Line of Credit Facility [Line Items]
Number of real estate properties owned | Property		14		13
Revised Wells Fargo Line of Credit | Wells Fargo Bank
Line of Credit Facility [Line Items]
Line of credit, term	3 years
Number of extensions | extension_option	2
Extension period	1 year
Maximum borrowing capacity	$ 100,000,000	$ 89,310,000
Maximum borrowing capacity, expansion	200,000,000
Expansion feature, minimum increase limit for each request	$ 25,000,000
Long-term line of credit		$ 77,600,000	$ 81,600,000
Line of credit, interest rate at period end		1.85%	3.33%
Percentage of property value	65.00%
Percentage of minimum debt yield	9.00%
Number of real estate properties owned | Property	5
Revised Wells Fargo Line of Credit | Wells Fargo Bank | Minimum | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.60%
Revised Wells Fargo Line of Credit | Wells Fargo Bank | Maximum | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.80%