Significant Transactions - Summary of Apartment Community Dispositions (Details) $ in Thousands		12 Months Ended
		Dec. 31, 2020 USD ($) Property apartment_home	Dec. 31, 2019 USD ($) Property apartment_home	Dec. 31, 2018 USD ($) Property apartment_home	Sep. 08, 2020 apartment_home Multi_family_apartment
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of apartment communities sold | Multi_family_apartment					12
Number of apartment homes sold | apartment_home					4,051
Gain on dispositions of real estate and the Asset Management business | $		$ 119,215	$ 503,168	$ 677,463
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Wholly And Partially Owned Consolidated Properties
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of apartment communities sold | Property		2	12	4
Number of apartment homes sold | apartment_home		485	3,596	1,334
Gain on dispositions of real estate and the Asset Management business | $	[1]	$ 119,215	$ 503,168	$ 175,213

[1] (1) During the year ended December 31, 2019, gain on dispositions of real estate includes the gain recognized upon the expiration of indemnification liabilities related to the sale of our Asset Management business.