SEGMENT INFORMATION - Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenues
Rental income	$ 374,245	$ 352,743
Income from loans and investments	1,289	13,589
Interest and other income	6,780	1,743
Revenues	1,199,914	1,077,245
Less:
Interest and other income	6,780	1,743
Property-level operating expenses	687,497	607,931
NOI	503,884	465,865
Interest and other income	6,780	1,743
Interest expense	(149,933)	(128,075)
Depreciation and amortization	(300,255)	(282,119)
General, administrative and professional fees	(48,737)	(44,798)
Loss on extinguishment of debt, net	(252)	0
Transaction, transition and restructuring costs	(4,677)	(1,386)
Allowance on loans receivable and investments	68	8,064
Shareholder relations matters	(15,714)	0
Other income	1,334	(7,762)
Loss from unconsolidated entities	(8,383)	(5,623)
Gain on real estate dispositions	341	10,201
Income tax benefit	3,004	2,802
Loss from continuing operations	(12,540)	18,912
Net (loss) income	(12,540)	18,912
Net income attributable to noncontrolling interests	1,772	1,395
Net loss attributable to common stockholders	(14,312)	17,517
Resident fees and services
Revenues
Other revenues	813,304	704,993
Third party capital management expenses
Revenues
Other revenues	4,296	4,177
Less:
Third party capital management expenses	1,753	1,706
Operating Segments | SHOP
Revenues
Rental income	0	0
Income from loans and investments	0	0
Interest and other income	0	0
Revenues	813,304	704,993
Less:
Interest and other income	0	0
Property-level operating expenses	609,821	537,222
NOI		167,771
Interest and other income	0	0
Operating Segments | SHOP | Resident fees and services
Revenues
Other revenues	813,304	704,993
Operating Segments | SHOP | Third party capital management expenses
Revenues
Other revenues	0	0
Less:
Third party capital management expenses	0	0
Operating Segments | Outpatient Medical and Research Portfolio
Revenues
Rental income	218,877	203,004
Income from loans and investments	0	0
Interest and other income	0	0
Revenues	219,508	203,632
Less:
Interest and other income	0	0
Property-level operating expenses	73,938	66,913
NOI	145,570	136,719
Interest and other income	0	0
Operating Segments | Outpatient Medical and Research Portfolio | Resident fees and services
Revenues
Other revenues	0	0
Operating Segments | Outpatient Medical and Research Portfolio | Third party capital management expenses
Revenues
Other revenues	631	628
Less:
Third party capital management expenses	0	0
Operating Segments | Triple-Net Leased Properties
Revenues
Rental income	155,368	149,739
Income from loans and investments	0	0
Interest and other income	0	0
Revenues	155,368	149,739
Less:
Interest and other income	0	0
Property-level operating expenses	3,738	3,796
NOI	151,630	145,943
Interest and other income	0	0
Operating Segments | Triple-Net Leased Properties | Resident fees and services
Revenues
Other revenues	0	0
Operating Segments | Triple-Net Leased Properties | Third party capital management expenses
Revenues
Other revenues	0	0
Less:
Third party capital management expenses	0	0
Operating Segments | Senior Living Operations
Less:
NOI	203,483
Non-Segment
Revenues
Rental income	0	0
Income from loans and investments	1,289	13,589
Interest and other income	6,780	1,743
Revenues	11,734	18,881
Less:
Interest and other income	6,780	1,743
Property-level operating expenses	0	0
NOI	3,201	15,432
Interest and other income	6,780	1,743
Non-Segment | Resident fees and services
Revenues
Other revenues	0	0
Non-Segment | Third party capital management expenses
Revenues
Other revenues	3,665	3,549
Less:
Third party capital management expenses	$ 1,753	$ 1,706