RENTAL PROPERTIES (Details)	6 Months Ended
	Jun. 30, 2019 USD ($) property item	Dec. 31, 2018 USD ($)	Jun. 30, 2018 property
RENTAL PROPERTIES
Number of units | property			913
Rental properties
Total fixed assets	$ 339,618,399	$ 337,902,411
Less: Accumulated depreciation	(114,480,889)	(107,391,148)
Total fixed assets, net	225,137,510	230,511,263
Land, improvements and parking lots
Rental properties
Total fixed assets	$ 72,554,622	72,547,547
Land, improvements and parking lots | Minimum
Rental properties
Useful Life	15 years
Land, improvements and parking lots | Maximum
Rental properties
Useful Life	40 years
Buildings and improvements
Rental properties
Total fixed assets	$ 221,865,864	221,697,939
Buildings and improvements | Minimum
Rental properties
Useful Life	15 years
Buildings and improvements | Maximum
Rental properties
Useful Life	40 years
Kitchen cabinets
Rental properties
Total fixed assets	$ 12,516,335	12,134,519
Kitchen cabinets | Minimum
Rental properties
Useful Life	5 years
Kitchen cabinets | Maximum
Rental properties
Useful Life	10 years
Carpets
Rental properties
Total fixed assets	$ 8,022,028	7,591,591
Carpets | Minimum
Rental properties
Useful Life	5 years
Carpets | Maximum
Rental properties
Useful Life	10 years
Air conditioning
Rental properties
Total fixed assets	$ 603,149	603,149
Air conditioning | Minimum
Rental properties
Useful Life	5 years
Air conditioning | Maximum
Rental properties
Useful Life	10 years
Laundry equipment
Rental properties
Total fixed assets	$ 349,071	327,643
Laundry equipment | Minimum
Rental properties
Useful Life	5 years
Laundry equipment | Maximum
Rental properties
Useful Life	7 years
Elevators
Rental properties
Total fixed assets	$ 1,885,265	1,839,590
Elevators | Minimum
Rental properties
Useful Life	20 years
Elevators | Maximum
Rental properties
Useful Life	40 years
Swimming pools
Rental properties
Total fixed assets	$ 444,629	444,629
Swimming pools | Minimum
Rental properties
Useful Life	10 years
Swimming pools | Maximum
Rental properties
Useful Life	30 years
Equipment
Rental properties
Total fixed assets	$ 13,110,356	12,919,389
Equipment | Minimum
Rental properties
Useful Life	5 years
Equipment | Maximum
Rental properties
Useful Life	30 years
Motor vehicles
Rental properties
Total fixed assets	$ 216,260	216,260
Motor vehicles | Maximum
Rental properties
Useful Life	5 years
Fences
Rental properties
Total fixed assets	$ 38,213	38,213
Fences | Minimum
Rental properties
Useful Life	5 years
Fences | Maximum
Rental properties
Useful Life	15 years
Furniture and fixtures
Rental properties
Total fixed assets	$ 7,484,510	7,013,845
Furniture and fixtures | Minimum
Rental properties
Useful Life	5 years
Furniture and fixtures | Maximum
Rental properties
Useful Life	7 years
Smoke alarms
Rental properties
Total fixed assets	$ 528,097	$ 528,097
Smoke alarms | Minimum
Rental properties
Useful Life	5 years
Smoke alarms | Maximum
Rental properties
Useful Life	7 years
Wholly owned properties
RENTAL PROPERTIES
Number of properties | item	27
Investment Properties
RENTAL PROPERTIES
Number of units | property	913
Residential and mixed-use properties
RENTAL PROPERTIES
Number of units | item	2,711
Number of properties | item	23
Residential and mixed-use properties | Partially owned properties
RENTAL PROPERTIES
Number of units | item	688
Number of properties | item	8
Residential and mixed-use properties | Partially owned properties | Minimum
RENTAL PROPERTIES
Ownership interest (as a percent)	40.00%
Residential and mixed-use properties | Partially owned properties | Maximum
RENTAL PROPERTIES
Ownership interest (as a percent)	50.00%
Residential and mixed-use properties | Investment Properties | Partially owned properties
RENTAL PROPERTIES
Number of units | property	688
Condominium
RENTAL PROPERTIES
Number of units | item	19
Condominium | Wholly owned properties
RENTAL PROPERTIES
Number of units | item	19
Number of properties | item	1