Real Estate Disposition Activities (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) community land_parcel home	Mar. 31, 2016 USD ($)
Summary of income from discontinued operations
Gain on sale of communities	$ 87,949	$ 51,430
Number of land parcels sold | land_parcel	2
Number of owned communities under construction | community	24
Gain on sale of other real estate	$ 366	$ 0
Number of communities held for sale | community	0
Avalon Pines [Member]
Summary of income from discontinued operations
Apartment homes | home	450
Proceeds from sale of real estate	$ 140,000
Gain on sale of communities	87,949
Other Real Estate Sales [Member]
Summary of income from discontinued operations
Proceeds from sale of real estate	22,286
Gain on sale of other real estate	$ 366
Development Communities [Member] | Avalon Newcastle Commons I [Member]
Summary of income from discontinued operations
Number of owned communities under construction | community	1