Mortgages Payable Mortgage Payable by Property (Details) (USD $)	12 Months Ended			3 Months Ended	6 Months Ended		3 Months Ended	9 Months Ended			12 Months Ended
	Dec. 31, 2012	Feb. 28, 2013	Dec. 31, 2011	Mar. 31, 2011 Arboretum [Member]	Jun. 30, 2011 Eagle Village [Member]	Jun. 30, 2012 Glynn Place [Member]	Mar. 31, 2012 Residences at DeCordova [Member]	Sep. 30, 2011 Residences at Weatherford [Member]	Dec. 31, 2012 Real Estate [Member]	Dec. 31, 2011 Real Estate [Member]	Dec. 31, 2012 Real Estate [Member] Arboretum [Member]		Dec. 31, 2011 Real Estate [Member] Arboretum [Member]		Dec. 31, 2012 Real Estate [Member] Eagle Village [Member]		Dec. 31, 2011 Real Estate [Member] Eagle Village [Member]		Dec. 31, 2012 Real Estate [Member] Glynn Place [Member]		Dec. 31, 2011 Real Estate [Member] Glynn Place [Member]		Dec. 31, 2012 Real Estate [Member] Residences at DeCordova [Member]		Dec. 31, 2012 Real Estate [Member] Residences at Weatherford [Member]		Dec. 31, 2011 Real Estate [Member] Residences at Weatherford [Member]
Mortgage Loans on Real Estate [Line Items]
Long-term Debt	$ 39,119,507	$ 7,500,000	$ 35,464,455					$ 6,400,000	$ 39,119,507	$ 35,464,455	$ 17,500,000		$ 17,500,000		$ 8,925,000		$ 8,925,000		$ 4,252,836		$ 4,308,468		$ 1,995,628		$ 6,446,043		$ 4,730,987
Debt Instrument, Face Amount				$ 17,500,000	$ 8,900,000		$ 2,000,000	$ 6,500,000	$ 39,405,000	$ 35,635,987	$ 17,500,000		$ 17,500,000		$ 8,925,000		$ 8,925,000		$ 4,480,000		$ 4,480,000		$ 2,000,000		$ 6,500,000		$ 4,730,987
Long Term Debt, Maturity date at a point in time	Apr. 01, 2050			Mar. 31, 2014	Jun. 01, 2013	May 01, 2013	Feb. 01, 2017	Jul. 28, 2015			Mar. 01, 2014		Mar. 01, 2014		Jun. 01, 2013		Jun. 01, 2013		May 01, 2013		May 01, 2012		Feb. 01, 2017		Jul. 01, 2015		Jul. 01, 2015
Debt Instrument, Interest Rate, Effective Percentage											5.25%	[1]	5.25%	[1]	3.50%	[1]	3.50%	[1]	2.78%	[1]	2.99%	[1]	5.01%	[1]	5.84%	[1]	5.63%	[1]

[1] Represents the average effective interest rate, including fees, for the years ended December 31, 2012 and 2011 and excludes the effect of interest rate caps (see Note 15).