Reportable Segments - Reconciliation of NOI from Rental Real Estate Specific to Continuing Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Rental income	$ 622,433	$ 685,120	$ 1,958,270	$ 2,016,796
Property and maintenance expense	(113,065)	(114,966)	(333,333)	(338,497)
Real estate taxes and insurance expense	(95,273)	(87,546)	(288,043)	(270,434)
Operating income	182,410	368,338	961,384	947,232
Same Store, Non-same Store and Other
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Rental income	622,433	685,120	1,958,270	2,016,796
Property and maintenance expense	(113,065)	(114,966)	(333,333)	(338,497)
Real estate taxes and insurance expense	(95,273)	(87,546)	(288,043)	(270,434)
Total operating expenses	(208,338)	(202,512)	(621,376)	(608,931)
Operating income	$ 414,095	$ 482,608	$ 1,336,894	$ 1,407,865