Discontinued Operations (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of components from discontinued operations [Abstract]
Rental revenues	$ 608,000	$ 4,081,000	$ 5,453,000
Property operating expenses	(260,000)	(1,861,000)	(2,342,000)
Depreciation and amortization	(94,000)	(1,115,000)	(1,491,000)
Expenses	(354,000)	(2,976,000)	(3,833,000)
Operating income from real estate sold	254,000	1,105,000	1,620,000
Gain on sale of real estate	10,870,000	8,382,000	0
Internal disposition costs	(1,087,000)	(839,000)	0
Income from discontinued operations	10,037,000	8,648,000	1,620,000
Tierra Del Sol/Norte [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Units in the community	156
Sales price of communities sold	17,200,000
Gain on sale of real estate	7,000,000
Alpine Country [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Units in the community	108
Sales price of communities sold	11,100,000
Gain on sale of real estate	3,900,000
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