MORTGAGE NOTES PAYABLE (Details) (USD $)			0 Months Ended	9 Months Ended	0 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Jul. 15, 2013 Hamilton Green Apartments, LLC	Sep. 30, 2013 Mortgages payable	Sep. 30, 2013 Mortgages payable Hamilton Green Apartments, LLC	Feb. 25, 2013 Mortgages payable Hamilton Cypress LLC Commercial-1031Exchange Brookline, Massachusetts	Mar. 11, 2013 Mortgages payable Property located at School Street	Jul. 07, 2013 Mortgages payable Boylston Downtown L.P. Residential Apartments Boston, Massachusetts	Sep. 30, 2013 Mortgages payable Minimum	Sep. 30, 2013 Mortgages payable Maximum
MORTGAGE NOTES PAYABLE
Interest rate (as a percent)					4.67%		3.70%	3.97%	2.44%	7.07%
Amount of monthly installments including principal				$ 791,000
Weighted average interest rate (as a percent)				4.84%
Effective interest rate (as a percent)	5.47%			4.98%
Annual maturities of mortgage debt
2014-current maturities	1,825,000
2015	9,127,000
2016	945,000
2017	1,889,000
2018	9,158,000
Thereafter	169,030,000
Total	191,974,000
Additional disclosures related to mortgages
Amount of mortgage paid off						3,697,000
Mortgage prepayment penalties						0
Amount of new loan					38,500,000		15,000,000	40,000,000
Period of interest only payments on loans					15 years		3 years
Deferred financing cost associated with mortgage							159,000
Term of debt					15 years			15 years
Period for which the entity is required to make interest only payments					2 years			3 years
Amortization period of debt					30 years			30 years
Amount of loan proceeds utilized for pay off the existing mortgage								19,500,000
Outstanding amount of mortgage loan	191,974,239	138,055,522
Net proceed from the loan - cash back								20,000,000
Refinancing cost								279,000
Closing costs associated with financing			126,000		405,000
Proceeds from like kind exchange			$ 2,100,000