SEGMENT INFORMATION - Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Revenues
Rental income	$ 373,516	$ 372,787	$ 750,948	$ 747,032
Income from loans and investments	4,395	1,436	8,719	2,725
Interest and other income	5,871	4,825	8,949	11,605
Revenues	1,420,893	1,200,980	2,778,967	2,400,894
Less:
Interest and other income	5,871	4,825	8,949	11,605
Labor	420,212	343,099	812,836	687,806
Management fees	54,421	41,951	105,032	84,017
Other segment expenses	350,636	295,101	691,285	595,825
Property-level operating expenses	825,269	680,151	1,609,153	1,367,648
Third-party capital management expenses			3,452	3,403
NOI	588,126	514,354	1,157,413	1,018,238
Interest and other income	5,871	4,825	8,949	11,605
Interest expense	(150,298)	(149,259)	(299,654)	(299,192)
Depreciation and amortization	(347,719)	(339,848)	(669,244)	(640,103)
General, administrative and professional fees	(42,856)	(37,727)	(96,005)	(86,464)
Loss on extinguishment of debt, net	0	(420)	0	(672)
Transaction, transition and restructuring costs	(4,627)	(2,886)	(10,609)	(7,563)
Recovery of allowance on loans receivable and investments, net		42		110
Shareholder relations matters	0	(37)	0	(15,751)
Other expense	(5,839)	(8,128)	(7,251)	(6,794)
Loss from unconsolidated entities	(1,138)	(1,652)	(4,449)	(10,035)
Gain on real estate dispositions	33,816	49,670	33,985	50,011
Income tax expense	(3,874)	(7,766)	6,683	(4,762)
Net income	71,462	21,168	119,818	8,628
Net income attributable to noncontrolling interests	3,198	1,781	4,686	3,553
Net income attributable to common stockholders	68,264	19,387	115,132	5,075
Resident fees and services
Revenues
Other revenues	1,032,714	817,600	2,001,618	1,630,904
Third-party capital management expenses
Revenues
Other revenues	4,397	4,332	8,733	8,628
Less:
Third-party capital management expenses	1,627	1,650	3,452	3,403
Operating Segments | SHOP
Revenues
Rental income	0	0	308,815	0
Income from loans and investments	0	0	0	0
Interest and other income	0	0	0	0
Revenues	1,032,714	817,600	2,001,618	1,630,904
Less:
Interest and other income	0	0	0	0
Third-party capital management expenses			0	0
NOI		214,241		417,724
Interest and other income	0	0	0	0
Operating Segments | SHOP | Resident fees and services
Revenues
Other revenues	1,032,714	817,600	0	1,630,904
Operating Segments | SHOP | Third-party capital management expenses
Revenues
Other revenues	0	0	0	0
Less:
Third-party capital management expenses	0	0
Operating Segments | OM&R
Revenues
Rental income	220,814	218,853	442,133	437,730
Income from loans and investments	0	0	0	0
Interest and other income	0	0	0	0
Revenues	221,487	219,559	443,486	439,066
Less:
Interest and other income	0	0	0	0
Labor	0	0	0	0
Management fees	0	0	0	0
Other segment expenses	75,001	73,286	150,958	147,224
Property-level operating expenses	75,001	73,286	150,958	147,224
Third-party capital management expenses			0	0
NOI	146,486	146,273	292,528	291,842
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	673	706	1,353	1,336
Less:
Third-party capital management expenses	0	0
Operating Segments | NNN
Revenues
Rental income	152,702	153,934	0	309,302
Income from loans and investments	0	0	0	0
Interest and other income	0	0	0	0
Revenues	152,702	153,934	308,815	309,302
Less:
Interest and other income	0	0	0	0
Labor	0	0	0	0
Management fees	0	0	0	0
Other segment expenses	3,966	3,506	7,493	7,244
Property-level operating expenses	3,966	3,506	7,493	7,244
Third-party capital management expenses			0	0
NOI	148,736	150,428	301,322	302,058
Interest and other income	0	0	0	0
Operating Segments | NNN | Resident fees and services
Revenues
Other revenues	0	0	2,001,618	0
Operating Segments | NNN | Third-party capital management expenses
Revenues
Other revenues	0	0	0	0
Less:
Third-party capital management expenses	0	0
Operating Segments | Senior Living Operations
Less:
Labor	420,212	343,099	812,836	687,806
Management fees	54,421	41,951	105,032	84,017
Other segment expenses	271,669	218,309	532,834	441,357
Property-level operating expenses	746,302	603,359	1,450,702	1,213,180
NOI	286,412		550,916
Non-Segment
Revenues
Rental income	0	0	0	0
Income from loans and investments	4,395	1,436	8,719	2,725
Interest and other income	5,871	4,825	8,949	11,605
Revenues	13,990	9,887	25,048	21,622
Less:
Interest and other income	5,871	4,825	8,949	11,605
Labor	0	0	0	0
Management fees	0	0	0	0
Other segment expenses	0	0	0	0
Property-level operating expenses	0	0	0	0
Third-party capital management expenses			3,452	3,403
NOI	6,492	3,412	12,647	6,614
Interest and other income	5,871	4,825	8,949	11,605
Non-Segment | Resident fees and services
Revenues
Other revenues	0	0	0	0
Non-Segment | Third-party capital management expenses
Revenues
Other revenues	3,724	3,626	$ 7,380	$ 7,292
Less:
Third-party capital management expenses	$ 1,627	$ 1,650