SIGNIFICANT ACCOUNTING POLICIES (Details)		9 Months Ended
	Jan. 03, 2012	Sep. 30, 2016 USD ($) item shares	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	Jun. 30, 2013 USD ($)	Aug. 20, 2007
Principles of Consolidation
Value of equity method investment to discontinued partnership		$ 0
Revenue Recognition
Period for which arrears are charged against income		60 days
Income Taxes
Provision for income taxes		$ 0
Deferred financing costs				$ 1,400,000
Amortization of deferred financing costs		$ 141,000	$ 128,000
Segment Reporting
Number of segments | item		1
Income Per Unit
Dilutive units | shares		0
Concentration of Credit Risks and Financial Instruments
Federally uninsured amounts of cash and cash equivalents, and security deposits included in prepaid expenses and other assets		$ 9,241,000		$ 11,592,000
Advertising Expense
Advertising expense		154,105	106,482
Interest Capitalized
Capitalized interest		$ 0	$ 0
Minimum
Principles of Consolidation
Ownership interest in each subsidiary (as a percent)		99.67%
Interest Capitalized
Criteria of capitalization of interest on property based on specified period of construction		1 year
Minimum | Cash and cash equivalents
Concentration of Credit Risks and Financial Instruments
Interest rate on interest bearing accounts (as a percent)		0.01%
Maximum
Principles of Consolidation
Ownership interest in each subsidiary (as a percent)		100.00%
Maximum | Cash and cash equivalents
Concentration of Credit Risks and Financial Instruments
Interest rate on interest bearing accounts (as a percent)		0.35%
Investment Properties
Principles of Consolidation
Number of limited liability companies/partnerships | item		9
Investment Properties | Minimum
Principles of Consolidation
Percentage of ownership interest		40.00%
Investment Properties | Maximum
Principles of Consolidation
Percentage of ownership interest		50.00%
345 Franklin
Principles of Consolidation
Value of equity method investment to discontinued partnership					$ 0
Class A
Income (Loss) Per Depositary Receipt
Forward split of depositary receipts	3
Exchange ratio of depositary receipts for partnership units before adjustment	10
Exchange ratio of depositary receipts for partnership units after adjustment	30
Number of units in each depository receipt	0.03333					0.1