Real Estate Disposition Activities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) community land_parcel	Dec. 31, 2016 USD ($) community land_parcel	Dec. 31, 2016 USD ($) community land_parcel	Dec. 31, 2016 USD ($) community land_parcel home	Dec. 31, 2016 USD ($) community land_parcel	Dec. 31, 2016 USD ($) community land_parcel building	Dec. 31, 2015 USD ($) home	Dec. 31, 2014 USD ($) home
Summary of income from discontinued operations
Number of owned communities under construction | community	27	27	27	27	27	27
Gain on sale of communities					$ 374,623		$ 115,625	$ 84,925
Number of Land Parcels Sold | land_parcel			1
Gain on sale of other real estate					$ 10,224		$ 9,647	$ 490
Accounts receivable, balance to be received, period	35 years
Number of Land Parcels Held For Sale | land_parcel	2	2	2	2	2	2
Eaves Trumbull [Member]
Summary of income from discontinued operations
Apartment homes | home				340
Gross sales price					$ 70,250
Net cash proceeds (1)					68,665
Avalon Essex
Summary of income from discontinued operations
Apartment homes | home				154
Gross sales price					45,100
Net cash proceeds (1)					44,085
Eaves Nanuet
Summary of income from discontinued operations
Apartment homes | home				504
Gross sales price					147,000
Net cash proceeds (1)					145,722
Avalon Shrewsbury
Summary of income from discontinued operations
Apartment homes | home				251
Gross sales price					60,500
Net cash proceeds (1)					59,263
Avalon at Freehold
Summary of income from discontinued operations
Apartment homes | home				296
Gross sales price					68,000
Net cash proceeds (1)					66,320
Avalon Brandemoor I and II [Member]
Summary of income from discontinued operations
Apartment homes | home				506
Gross sales price					132,000
Net cash proceeds (1)					128,021
Other Real Estate Sales [Member]
Summary of income from discontinued operations
Gain on sale of other real estate					10,224
Gross sales price					41,178
Net cash proceeds (1)					20,641
West Hollywood Affordable [Member]
Summary of income from discontinued operations
Number of apartment buildings sold		1				1
Apartment homes | home				77
Accounts Receivable, Net	$ 18,643	$ 18,643	$ 18,643	$ 18,643	18,643	$ 18,643
Accounts Receivable, Net, Current	$ 16,891	$ 16,891	$ 16,891	$ 16,891	16,891	$ 16,891
Wholly Owned Properties
Summary of income from discontinued operations
Number of apartment communities sold | community		7
Sale of Communities Gross Sales Price					522,850
Gain on sale of communities					370,301
Apartment homes | home				2,051			851	1,337
Repayments of secured mortgages					0		$ 0	$ 16,341
Gross sales price					564,028		289,320	304,250
Net cash proceeds (1)					$ 532,717		$ 282,163	$ 281,125
AVA North Point [Member]
Summary of income from discontinued operations
Equity Method Investment, Ownership Percentage	55.00%	55.00%	55.00%	55.00%	55.00%	55.00%
Gain on sale of other real estate					$ 10,621
Avalon West Hollywood [Member] | Development Communities [Member]
Summary of income from discontinued operations
Number of owned communities under construction | community	1	1	1	1	1	1