Discontinued Operations (Details) (USD $)	3 Months Ended		9 Months Ended		3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Mar. 31, 2012 Tierra Del Sol Norte [Member]	Mar. 31, 2012 Alpine Country [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Units in the community					156	108
Sales price of communities sold					$ 17,200,000	$ 11,100,000
Gain on sale of real estate	0	0	10,870,000	5,854,000	7,000,000	3,900,000
Schedule of components from discontinued operations [Abstract]
Rental revenues	0	892,000	608,000	3,239,000
Property operating expenses	0	(435,000)	(260,000)	(1,459,000)
Depreciation and amortization	0	(256,000)	(94,000)	(892,000)
Income from real estate sold	0	201,000	254,000	888,000
Internal dispositon costs and taxes	0	(880,000)	(1,087,000)	(1,469,000)
Income (loss) from discontinued operations	$ 0	$ (679,000)	$ 10,037,000	$ 5,273,000