SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Concentration of Credit Risk (Details) - tenant	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Square Footage | Geographic Concentration Risk | Income Properties
CONCENTRATION OF CREDIT RISK
Concentration risk percentage		18.10%
Square Footage | Geographic Concentration Risk | Income Properties | Florida
CONCENTRATION OF CREDIT RISK
Concentration risk percentage	23.00%	26.00%
Square Footage | Geographic Concentration Risk | Income Properties | Georgia
CONCENTRATION OF CREDIT RISK
Concentration risk percentage	13.00%	11.00%
Square Footage | Geographic Concentration Risk | Income Properties | New Mexico
CONCENTRATION OF CREDIT RISK
Concentration risk percentage	13.00%
Square Footage | Geographic Concentration Risk | Income Properties | North Carolina
CONCENTRATION OF CREDIT RISK
Concentration risk percentage	12.00%	20.00%
Square Footage | Geographic Concentration Risk | Income Properties | Texas
CONCENTRATION OF CREDIT RISK
Concentration risk percentage	16.00%	17.00%
Square Footage | Geographic Concentration Risk | Income Properties | Arizona
CONCENTRATION OF CREDIT RISK
Concentration risk percentage		12.00%
Multi-Tenant Income Property | Geographic Concentration Risk | Income Properties | Income Property, Multi-tenant, Ashford Lane, Atlanta, Georgia
CONCENTRATION OF CREDIT RISK
Concentration risk percentage	10.50%
Multi-Tenant Income Property | Geographic Concentration Risk | Income Properties | Income Property, Multi Tenant, Beaver Creek, Apex, North Carolina
CONCENTRATION OF CREDIT RISK
Concentration risk percentage	11.80%
Base Rent Revenues
CONCENTRATION OF CREDIT RISK
Number of tenants	1
Base Rent Revenues | Geographic Concentration Risk | Florida
CONCENTRATION OF CREDIT RISK
Concentration risk percentage	31.00%
Base Rent Revenues | Geographic Concentration Risk | Georgia
CONCENTRATION OF CREDIT RISK
Concentration risk percentage	13.00%
Base Rent Revenues | Geographic Concentration Risk | Texas
CONCENTRATION OF CREDIT RISK
Concentration risk percentage	16.00%
Base Rent Revenues | Geographic Concentration Risk | Arizona
CONCENTRATION OF CREDIT RISK
Concentration risk percentage	11.00%
Base Rent Revenues | Customer Concentration Risk | Income Property, Wells Fargo, Raleigh, North Carolina
CONCENTRATION OF CREDIT RISK
Concentration risk percentage		10.90%	12.50%