RELATED PARTY TRANSACTIONS (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) member property board_member	Dec. 31, 2022 USD ($) property	Dec. 31, 2021 USD ($) property	Apr. 30, 2023
Related party transaction
Number of Properties | property	1,355
Total rental income	$ 1,486,401	$ 1,399,313	$ 1,448,120
Income from loans and investments	22,952	48,160	74,981
Interest and other income	11,414	3,635	14,809
Revenues	4,497,827	4,129,193	3,828,007
Property-level operating expenses	2,555,145	2,276,724	2,084,064
Third party capital management expenses	6,101	6,194	4,433
NOI	1,925,167	1,842,640	1,724,701
Resident fees and services
Related party transaction
Revenue from contracts with customers	2,959,219	2,651,886	2,270,001
Third party capital management revenues
Related party transaction
Revenue from contracts with customers	17,841	26,199	20,096
Operating Segments | Outpatient Medical And Research Portfolio
Related party transaction
Total rental income	867,193	801,159	794,297
Income from loans and investments	0	0	0
Interest and other income	0	0	0
Revenues	869,708	803,607	802,681
Property-level operating expenses	292,776	257,003	257,001
Third party capital management expenses	0	0	1,798
NOI	576,932	546,604	543,882
Operating Segments | Outpatient Medical And Research Portfolio | Resident fees and services
Related party transaction
Revenue from contracts with customers	0	0	0
Operating Segments | Outpatient Medical And Research Portfolio | Third party capital management revenues
Related party transaction
Revenue from contracts with customers	$ 2,515	$ 2,448	$ 8,384
Seniors Housing Communities | Dispositions
Related party transaction
Number of Properties | property		7
Eclipse Senior Living (ESL) | Seniors Housing Communities | Dispositions
Related party transaction
Number of Properties | property		90	90
Ardent | Triple-net leased properties
Related party transaction
Number of Properties | property	11
Ardent | Outpatient Medical Buildings And Other
Related party transaction
Number of Properties | property	19
PMB RES
Related party transaction
Costs and Expenses, Related Party	$ 10,900	$ 8,500	$ 9,200
Atria
Related party transaction
Ownership interests	34.00%
Number of board members appointed | board_member	2
Equity Method Investment, Rights To Appoint Board of Directors | member	2
Ardent
Related party transaction
Ownership interests	7.50%			9.80%
Eclipse Senior Living (ESL)
Related party transaction
Ownership interests		34.00%
Number of board members appointed | board_member	2
PMB RES
Related party transaction
Ownership interests	50.00%
Atria
Related party transaction
Costs and Expenses, Related Party	$ 63,400	$ 61,500	50,800
Atria | Sale Or Transition Of Senior Housing Communities Operated By Related Party
Related party transaction
Costs and Expenses, Related Party	$ 1,500	$ 6,100	$ 20,300
Ardent | Triple-net leased properties
Related party transaction
Revenue, Related Party, Type [Extensible Enumeration]	Other Affiliates [Member]	Other Affiliates [Member]	Other Affiliates [Member]
Ardent | Outpatient Medical Buildings And Other
Related party transaction
Revenue, Related Party, Type [Extensible Enumeration]	Other Affiliates [Member]
Eclipse Senior Living (ESL)
Related party transaction
Costs and Expenses, Related Party	$ 0	$ 0	$ 11,800
Eclipse Senior Living (ESL) | Transition Of Operations At Senior Housing Communities
Related party transaction
Costs and Expenses, Related Party			$ 24,000