Discontinued Operations (Details) (USD $)	3 Months Ended		9 Months Ended		1 Months Ended	3 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Aug. 31, 2013 Linden Square [Member]	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					$ 25,300,000	$ 17,200,000	$ 11,100,000
Gain on sale of real estate					12,700,000	7,000,000	3,900,000
Schedule of components from discontinued operations [Abstract]
Rental revenues	385,000	552,000	1,578,000	2,275,000
Property operating expenses	(151,000)	(236,000)	(573,000)	(997,000)
Depreciation and amortization	(49,000)	(144,000)	(342,000)	(533,000)
Income from real estate sold	185,000	172,000	663,000	745,000
Gain on sale	12,658,000	0	12,658,000	10,870,000
Internal disposition costs and taxes	0	0	0	(1,087,000)
Income from discontinued operations	$ 12,843,000	$ 172,000	$ 13,321,000	$ 10,528,000