Discontinued Operations (Details) (USD $)	3 Months Ended		6 Months Ended		3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Mar. 31, 2012 Tierra Del Sol/Norte [Member] Unit	Mar. 31, 2012 Alpine Country [Member] Unit
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					7,000,000	3,900,000
Schedule of components from discontinued operations [Abstract]
Rental revenues	0	0	0	608,000
Property operating expenses	0	0	0	(260,000)
Depreciation and amortization	0	0	0	(94,000)
Income from real estate sold	0	0	0	254,000
Gain on sale	0	0	0	10,870,000
Internal disposition costs and taxes	0	0	0	(1,087,000)
Income from discontinued operations	$ 0	$ 0	$ 0	$ 10,037,000