Real Estate Disposition Activities (Details) ft² in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) community home residential_condominium ft²	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Summary of income from discontinued operations
Gain (Loss) on Sale of Other Investments	$ 4,903	$ 0
Gain on sale of communities	$ 24,436	14,835
Number Of Communities Held For Sale | community	1
Number of Residential Condominium Units Sold | residential_condominium	36
Other Selling, General and Administrative Expense	$ 1,443	$ 473
For-sale condominium inventory	$ 365,120		$ 457,809
Avalon Shelton [Member]
Summary of income from discontinued operations
Number Of Apartment Homes Sold | home	250
Proceeds from Sale of Real Estate	$ 64,750
Gain on sale of communities	24,413
The Park Loggia [Member]
Summary of income from discontinued operations
Proceeds from Sale of Real Estate	105,607
Gain (Loss) on Sale of Other Investments	$ 4,903
Number Of Residential Condominium Units | home	172
Retail Square Feet | ft²	67