RENTAL PROPERTIES (Details)	9 Months Ended
	Sep. 30, 2017 USD ($) property item	Dec. 31, 2016 USD ($)	Sep. 30, 2016 property
Rental properties
Total fixed assets	$ 312,784,092	$ 263,659,293
Less: Accumulated depreciation	(103,634,403)	(94,196,482)
Total fixed assets, net	209,149,689	169,462,811
Land, improvements and parking lots
Rental properties
Total fixed assets	$ 64,694,380	52,612,929
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	$ 202,705,581	173,536,288
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	$ 12,585,369	8,738,323
Kitchen cabinets | Minimum
Rental properties
Useful Life	5 years
Kitchen cabinets | Maximum
Rental properties
Useful Life	10 years
Carpets
Rental properties
Total fixed assets	$ 9,181,606	7,621,292
Carpets | Minimum
Rental properties
Useful Life	5 years
Carpets | Maximum
Rental properties
Useful Life	10 years
Air conditioning
Rental properties
Total fixed assets	$ 690,535	690,535
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	$ 274,389	269,784
Laundry equipment | Minimum
Rental properties
Useful Life	5 years
Laundry equipment | Maximum
Rental properties
Useful Life	7 years
Elevators
Rental properties
Total fixed assets	$ 1,139,296	1,139,296
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	$ 10,816,225	10,029,639
Equipment | Minimum
Rental properties
Useful Life	5 years
Equipment | Maximum
Rental properties
Useful Life	30 years
Motor vehicles
Rental properties
Total fixed assets	$ 237,954	237,954
Motor vehicles | Maximum
Rental properties
Useful Life	5 years
Fences
Rental properties
Total fixed assets	$ 37,465	37,465
Fences | Minimum
Rental properties
Useful Life	5 years
Fences | Maximum
Rental properties
Useful Life	15 years
Furniture and fixtures
Rental properties
Total fixed assets	$ 9,316,804	8,127,100
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	$ 659,859	$ 174,059
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	26
Investment Properties
RENTAL PROPERTIES
Number of units | property	1,033		1,033
Residential and mixed-use properties
RENTAL PROPERTIES
Number of units | item	2,632
Number of properties | item	22
Residential and mixed-use properties | Partially owned properties
RENTAL PROPERTIES
Number of units | item	739
Number of properties | item	9
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	739
Condominium
RENTAL PROPERTIES
Number of units | item	19
Condominium | Wholly owned properties
RENTAL PROPERTIES
Number of units | item	19
Number of properties | item	1