Organization, Basis of Presentation, and Significant Accounting Policies Organization - Revenue and Gain Recognition (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Management, development and other fees	$ 3,084	$ 3,819	$ 4,960
Rental and other income	2,291,766	2,297,442	2,319,666
Total revenue	2,294,850	2,301,261	2,324,626
Non-allocated
Disaggregation of Revenue [Line Items]
Total revenue	3,084	1,978	4,960
Same Store | Operating segment
Disaggregation of Revenue [Line Items]
Total revenue	2,046,173	2,082,183	2,040,575
Other Stabilized Communities | Operating segment
Disaggregation of Revenue [Line Items]
Total revenue	104,357	79,431	110,434
Continuing Operations
Disaggregation of Revenue [Line Items]
Management, development and other fees	12,765	11,596	13,612
Rental and other income	2,239,228	2,179,915	2,169,695
Business interruption insurance proceeds	0	379	1,439
Total revenue	2,251,993	2,191,890	2,184,746
Continuing Operations | Management, development and other fees and other ancillary items
Disaggregation of Revenue [Line Items]
Management, development and other fees	3,084	1,978	4,960
Continuing Operations | Rental and non-rental related income
Disaggregation of Revenue [Line Items]
Management, development and other fees	9,681	9,618	8,652
Continuing Operations | Non-allocated
Disaggregation of Revenue [Line Items]
Management, development and other fees	3,084	1,978	4,960
Rental and other income	0	0	0
Business interruption insurance proceeds	0	0	0
Total revenue	3,084	1,978	4,960
Continuing Operations | Non-allocated | Management, development and other fees and other ancillary items
Disaggregation of Revenue [Line Items]
Management, development and other fees	3,084	1,978	4,960
Continuing Operations | Non-allocated | Rental and non-rental related income
Disaggregation of Revenue [Line Items]
Management, development and other fees	0	0	0
Continuing Operations | Same Store | Operating segment
Disaggregation of Revenue [Line Items]
Management, development and other fees	7,356	7,200	7,028
Rental and other income	2,038,817	2,074,604	2,032,561
Business interruption insurance proceeds	0	379	986
Total revenue	2,046,173	2,082,183	2,040,575
Continuing Operations | Same Store | Operating segment | Management, development and other fees and other ancillary items
Disaggregation of Revenue [Line Items]
Management, development and other fees	0	0	0
Continuing Operations | Same Store | Operating segment | Rental and non-rental related income
Disaggregation of Revenue [Line Items]
Management, development and other fees	7,356	7,200	7,028
Continuing Operations | Other Stabilized Communities | Operating segment
Disaggregation of Revenue [Line Items]
Management, development and other fees	1,650	2,056	1,224
Rental and other income	102,707	77,375	108,757
Business interruption insurance proceeds	0	0	453
Total revenue	104,357	79,431	110,434
Continuing Operations | Other Stabilized Communities | Operating segment | Management, development and other fees and other ancillary items
Disaggregation of Revenue [Line Items]
Management, development and other fees	0	0	0
Continuing Operations | Other Stabilized Communities | Operating segment | Rental and non-rental related income
Disaggregation of Revenue [Line Items]
Management, development and other fees	1,650	2,056	1,224
Continuing Operations | Development/ Redevelopment Communities | Operating segment
Disaggregation of Revenue [Line Items]
Management, development and other fees	675	362	400
Rental and other income	97,704	27,936	28,377
Business interruption insurance proceeds	0	0	0
Total revenue	98,379	28,298	28,777
Continuing Operations | Development/ Redevelopment Communities | Operating segment | Management, development and other fees and other ancillary items
Disaggregation of Revenue [Line Items]
Management, development and other fees	0	0	0
Continuing Operations | Development/ Redevelopment Communities | Operating segment | Rental and non-rental related income
Disaggregation of Revenue [Line Items]
Management, development and other fees	$ 675	$ 362	$ 400