RENTAL INCOME (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
RENTAL INCOME
Percentage of rental income related to residential apartments and condominium units with leases of one year or less	93.00%
Maximum period of non-cancelable operating lease	1 year
Percentage of rental income related to commercial properties	7.00%
Minimum future rental income
2018	$ 2,623,000
2019	2,131,000
2020	1,767,000
2021	1,325,000
2022	565,000
Thereafter	1,159,000
Commercial Property Leases	9,570,000
Aggregate contingent rentals from continuing operations	$ 642,000	$ 616,000	$ 683,000