Reportable Segments - Reconciliation of NOI from Rental Real Estate Specific to Continuing Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Rental income	$ 2,463,997	$ 2,571,705	$ 2,700,691
Property and maintenance expense	(453,532)	(440,998)	(446,845)
Real estate taxes and insurance expense	(397,105)	(381,562)	(366,139)
Operating income	1,675,841	1,317,990	1,356,160
Same Store, Non-same Store and Other
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Rental income	2,463,997	2,571,705	2,700,691
Property and maintenance expense	(453,532)	(440,998)	(446,845)
Real estate taxes and insurance expense	(397,105)	(381,562)	(366,139)
Total operating expenses	(850,637)	(822,560)	(812,984)
Operating income	$ 1,613,360	$ 1,749,145	$ 1,887,707