Discontinued Operations (Details) (USD $)	12 Months Ended
	Dec. 31, 2013 Community	Dec. 31, 2012 Community	Dec. 31, 2011
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of communities sold	3	2
Schedule of components from discontinued operations [Abstract]
Rrevenues	$ 4,454,000	$ 5,848,000	$ 9,133,000
Property operating expenses	(1,406,000)	(2,181,000)	(3,584,000)
Depreciation and amortization	(1,098,000)	(1,513,000)	(2,534,000)
Expenses	(2,504,000)	(3,694,000)	(6,118,000)
Operating income from real estate sold	1,950,000	2,154,000	3,015,000
Gain on sale of real estate	29,223,000	10,870,000	8,382,000
Internal disposition costs	0	(1,087,000)	(839,000)
Income from discontinued operations	31,173,000	11,937,000	10,558,000
Woodlawn Colonial [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales price of communities sold			23,400,000
Gain on sale of real estate			8,400,000
Number of communities sold			1
Number of office building sold			1
Linden Square [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Units in the community	183
Sales price of communities sold	25,300,000
Gain on sale of real estate	12,700,000
Cambridge [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Units in the community	40
Sales price of communities sold	4,700,000
Gain on sale of real estate	2,500,000
Brentwood [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Units in the community	140
Sales price of communities sold	27,500,000
Gain on sale of real estate	14,000,000
Tierra Del Sol/Norte and Alpine Country [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales price of communities sold		28,300,000
Gain on sale of real estate		$ 10,900,000
Number of communities sold		2