Discontinued Operations (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($) unit
Schedule of components from discontinued operations [Abstract]
Revenues			$ 4,454
Property operating expenses			(1,406)
Depreciation and amortization			(1,098)
Expenses			(2,504)
Operating income from real estate sold			1,950
Gain on sale of real estate			29,223
Income from discontinued operations	$ 0	$ 0	$ 31,173
Linden Square [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Units in the community | unit			183
Gain on sale of real estate			$ 12,700
Sales price of communities sold			$ 25,300
Cambridge [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Units in the community | unit			40
Gain on sale of real estate			$ 2,500
Sales price of communities sold			$ 4,700
Brentwood [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Units in the community | unit			140
Gain on sale of real estate			$ 14,000
Sales price of communities sold			$ 27,500