SEGMENT INFORMATION - Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Revenues
Rental income	$ 376,306	$ 386,138	$ 1,123,338	$ 1,109,043
Income from loans and investments	1,881	1,208	4,606	21,351
Interest and other income	8,204	2,754	19,809	5,529
Revenues	1,236,315	1,149,832	3,637,209	3,333,435
Less:
Interest and other income	8,204	2,754	19,809	5,529
Property-level operating expenses	713,408	656,477	2,081,056	1,887,226
Third party capital management expenses			4,956	4,614
NOI	513,150	489,129	1,531,388	1,436,066
Interest and other income	8,204	2,754	19,809	5,529
Interest expense	(150,437)	(147,919)	(449,629)	(419,259)
Depreciation and amortization	(304,268)	(370,377)	(944,371)	(957,185)
General, administrative and professional fees	(35,092)	(33,297)	(121,556)	(112,494)
Loss on extinguishment of debt, net	0	(612)	(672)	6,189
Transaction, transition and restructuring costs	(8,580)	(7,125)	(16,143)	(11,580)
Recovery of allowance on loans receivable and investments, net	56	66	166	20,195
Gain on foreclosure of real estate	0	0	0	29,127
Shareholder relations matters	0	0	(15,751)	0
Other expense	(3,935)	(9,432)	(10,729)	765
Income from unconsolidated entities	4,629	(5,119)	(5,406)	20,512
Gain on real estate dispositions	271	10,711	50,282	22,317
Income tax expense	(3,002)	1,662	(7,764)	14,237
Net income	20,996	(69,559)	29,624	54,419
Net income attributable to noncontrolling interests	1,753	1,565	5,306	4,573
Net income attributable to common stockholders	19,243	(71,124)	24,318	49,846
Resident fees and services
Revenues
Other revenues	845,532	754,417	2,476,436	2,184,024
Third party capital management expenses
Revenues
Other revenues	4,392	5,315	13,020	13,488
Less:
Third party capital management expenses	1,553	1,472	4,956	4,614
Third party capital management revenues
Revenues
Other revenues			13,020	13,488
Operating Segments | SHOP
Revenues
Rental income	0	0	0	0
Income from loans and investments	0	0	0	0
Interest and other income	0	0	0	0
Revenues	845,532	754,417	2,476,436	2,184,024
Less:
Interest and other income	0	0	0	0
Property-level operating expenses	631,550	573,715	1,844,730	1,658,047
Third party capital management expenses			0	0
NOI		180,702	631,706	525,977
Interest and other income	0	0	0	0
Operating Segments | SHOP | Resident fees and services
Revenues
Other revenues	845,532	754,417	2,476,436	2,184,024
Operating Segments | SHOP | Third party capital management expenses
Revenues
Other revenues	0	0
Less:
Third party capital management expenses	0	0
Operating Segments | SHOP | Third party capital management revenues
Revenues
Other revenues			0	0
Operating Segments | OM&R
Revenues
Rental income	220,957	226,326	658,687	645,137
Income from loans and investments	0	0	0	0
Interest and other income	0	0	0	0
Revenues	221,575	226,988	660,641	646,986
Less:
Interest and other income	0	0	0	0
Property-level operating expenses	77,479	78,915	224,703	217,999
Third party capital management expenses			0	0
NOI	144,096	148,073	435,938	428,987
Interest and other income	0	0	0	0
Operating Segments | OM&R | Resident fees and services
Revenues
Other revenues	0	0	0	0
Operating Segments | OM&R | Third party capital management expenses
Revenues
Other revenues	618	662
Less:
Third party capital management expenses	0	0
Operating Segments | OM&R | Third party capital management revenues
Revenues
Other revenues			1,954	1,849
Operating Segments | NNN
Revenues
Rental income	155,349	159,812	464,651	463,906
Income from loans and investments	0	0	0	0
Interest and other income	0	0	0	0
Revenues	155,349	159,812	464,651	463,906
Less:
Interest and other income	0	0	0	0
Property-level operating expenses	4,379	3,847	11,623	11,180
Third party capital management expenses			0	0
NOI	150,970	155,965	453,028	452,726
Interest and other income	0	0	0	0
Operating Segments | NNN | Resident fees and services
Revenues
Other revenues	0	0	0	0
Operating Segments | NNN | Third party capital management expenses
Revenues
Other revenues	0	0
Less:
Third party capital management expenses	0	0
Operating Segments | NNN | Third party capital management revenues
Revenues
Other revenues			0	0
Operating Segments | Senior Living Operations
Less:
NOI	213,982
Non-Segment
Revenues
Rental income	0	0	0	0
Income from loans and investments	1,881	1,208	4,606	21,351
Interest and other income	8,204	2,754	19,809	5,529
Revenues	13,859	8,615	35,481	38,519
Less:
Interest and other income	8,204	2,754	19,809	5,529
Property-level operating expenses	0	0	0	0
Third party capital management expenses			4,956	4,614
NOI	4,102	4,389	10,716	28,376
Interest and other income	8,204	2,754	19,809	5,529
Non-Segment | Resident fees and services
Revenues
Other revenues	0	0	0	0
Non-Segment | Third party capital management expenses
Revenues
Other revenues	3,774	4,653
Less:
Third party capital management expenses	$ 1,553	$ 1,472
Non-Segment | Third party capital management revenues
Revenues
Other revenues			$ 11,066	$ 11,639