SEGMENT INFORMATION - Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenues
Rental income	$ 372,787	$ 370,162	$ 747,032	$ 722,905
Income from loans and investments	1,436	6,554	2,725	20,143
Interest and other income	4,825	1,032	11,605	2,775
Revenues	1,200,980	1,106,358	2,400,894	2,183,603
Less:
Interest and other income	4,825	1,032	11,605	2,775
Property-level operating expenses	680,151	622,818	1,367,648	1,230,749
Third party capital management expenses			3,403	3,142
NOI	514,354	481,072	1,018,238	946,937
Interest and other income	4,825	1,032	11,605	2,775
Interest expense	(149,259)	(143,265)	(299,192)	(271,340)
Depreciation and amortization	(339,848)	(304,689)	(640,103)	(586,808)
General, administrative and professional fees	(37,727)	(34,399)	(86,464)	(79,197)
Loss on extinguishment of debt, net	(420)	6,801	(672)	6,801
Transaction, transition and restructuring costs	(2,886)	(3,069)	(7,563)	(4,455)
Allowance on loans receivable and investments, net	42	12,065	110	20,129
Gain on foreclosure of real estate	0	29,127	0	29,127
Shareholder relations matters	(37)	0	(15,751)	0
Other expense	(8,128)	17,959	(6,794)	10,197
Loss from unconsolidated entities	(1,652)	31,254	(10,035)	25,631
Gain on real estate dispositions	49,670	1,405	50,011	11,606
Income tax expense	(7,766)	9,773	(4,762)	12,575
Income from continuing operations	21,168	105,066	8,628	123,978
Net income	21,168	105,066	8,628	123,978
Net income attributable to noncontrolling interests	1,781	1,613	3,553	3,008
Net income attributable to common stockholders	19,387	103,453	5,075	120,970
Resident fees and services
Revenues
Other revenues	817,600	724,614	1,630,904	1,429,607
Third party capital management expenses
Revenues
Other revenues	4,332	3,996	8,628	8,173
Less:
Third party capital management expenses	1,650	1,436	3,403	3,142
Third party capital management revenues
Revenues
Other revenues			8,628	8,173
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	817,600	724,614	1,630,904	1,429,607
Less:
Interest and other income	0	0	0	0
Property-level operating expenses	603,359	547,110	1,213,180	1,084,332
Third party capital management expenses			0	0
NOI		177,504	417,724	345,275
Interest and other income	0	0	0	0
Operating Segments | SHOP | Resident fees and services
Revenues
Other revenues	817,600	724,614	1,630,904	1,429,607
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 | Outpatient Medical and Research Portfolio
Revenues
Rental income	218,853	215,807	437,730	418,811
Income from loans and investments	0	0	0	0
Interest and other income	0	0	0	0
Revenues	219,559	216,366	439,066	419,998
Less:
Interest and other income	0	0	0	0
Property-level operating expenses	73,286	72,171	147,224	139,084
Third party capital management expenses			0	0
NOI	146,273	144,195	291,842	280,914
Interest and other income	0	0	0	0
Operating Segments | Outpatient Medical and Research Portfolio | Resident fees and services
Revenues
Other revenues	0	0	0	0
Operating Segments | Outpatient Medical and Research Portfolio | Third party capital management expenses
Revenues
Other revenues	706	559
Less:
Third party capital management expenses	0	0
Operating Segments | Outpatient Medical and Research Portfolio | Third party capital management revenues
Revenues
Other revenues			1,336	1,187
Operating Segments | Triple-Net Leased Properties
Revenues
Rental income	153,934	154,355	309,302	304,094
Income from loans and investments	0	0	0	0
Interest and other income	0	0	0	0
Revenues	153,934	154,355	309,302	304,094
Less:
Interest and other income	0	0	0	0
Property-level operating expenses	3,506	3,537	7,244	7,333
Third party capital management expenses			0	0
NOI	150,428	150,818	302,058	296,761
Interest and other income	0	0	0	0
Operating Segments | Triple-Net Leased Properties | Resident fees and services
Revenues
Other revenues	0	0	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 | Triple-Net Leased Properties | Third party capital management revenues
Revenues
Other revenues			0	0
Operating Segments | Senior Living Operations
Less:
NOI	214,241
Non-Segment
Revenues
Rental income	0	0	0	0
Income from loans and investments	1,436	6,554	2,725	20,143
Interest and other income	4,825	1,032	11,605	2,775
Revenues	9,887	11,023	21,622	29,904
Less:
Interest and other income	4,825	1,032	11,605	2,775
Property-level operating expenses	0	0	0	0
Third party capital management expenses			3,403	3,142
NOI	3,412	8,555	6,614	23,987
Interest and other income	4,825	1,032	11,605	2,775
Non-Segment | Resident fees and services
Revenues
Other revenues	0	0	0	0
Non-Segment | Third party capital management expenses
Revenues
Other revenues	3,626	3,437
Less:
Third party capital management expenses	$ 1,650	$ 1,436
Non-Segment | Third party capital management revenues
Revenues
Other revenues			$ 7,292	$ 6,986