Discontinued Operations (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Schedule of components from discontinued operations [Abstract]
Rental revenues	$ 0	$ 608,000
Property operating expenses	0	(260,000)
Depreciation and amortization	0	(94,000)
Income from real estate sold	0	254,000
Gain on sale	0	10,870,000
Internal disposition costs and taxes	0	(1,087,000)
Income from discontinued operations	0	10,037,000
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