Segment Reporting - Summary Information for Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Segment Reporting Information [Line Items]
Resident fees and services	$ 2,061,370	$ 1,511,524	$ 5,896,944	$ 4,265,271
Rental income	499,475	430,486	1,444,082	1,183,949
Interest income	67,216	69,046	191,763	185,163
Other income	57,631	44,607	124,234	105,905
Total revenues	2,685,692	2,055,663	7,657,023	5,740,288
Property operating expenses	1,577,048	1,212,701	4,554,149	3,420,911
Consolidated net operating income (loss)	1,108,644	842,962	3,102,874	2,319,377
Depreciation and amortization	509,812	403,779	1,490,717	1,151,687
Interest expense	162,052	139,050	448,171	419,792
General and administrative expenses	63,124	77,901	191,057	186,784
Loss (gain) on derivatives and financial instruments, net	31,682	(9,906)	28,063	(18,785)
Loss (gain) on extinguishment of debt, net	0	419	6,156	2,130
Provision for loan losses, net	1,088	4,193	(2,032)	10,370
Impairment of assets	3,081	23,421	75,359	69,146
Other expenses	44,699	20,239	75,357	83,054
Income (loss) from continuing operations before income taxes and other items	293,106	183,866	790,026	415,199
Income tax (expense) benefit	(2,335)	4,706	2,131	(2,586)
Income (loss) from unconsolidated entities	(12,610)	(4,038)	(18,739)	(6,925)
Gain (loss) on real estate dispositions and acquisitions of controlling interests, net	4,025	272,266	70,652	443,416
Income (loss) from continuing operations	282,186	456,800	844,070	849,104
Net income (loss)	282,186	456,800	844,070	849,104
Seniors Housing Operating
Segment Reporting Information [Line Items]
Rental income			589,289	417,490
Operating Segments | Seniors Housing Operating
Segment Reporting Information [Line Items]
Resident fees and services	2,061,370	1,511,524	5,896,944	4,265,271
Rental income	0	0	0	0
Interest income	0	0	0	0
Other income	8,745	2,498	16,774	5,861
Total revenues	2,070,115	1,514,022	5,913,718	4,271,132
Property operating expenses	1,499,215	1,135,887	4,322,176	3,190,140
Consolidated net operating income (loss)	570,900	378,135	1,591,542	1,080,992
Operating Segments | Triple-net
Segment Reporting Information [Line Items]
Resident fees and services	0	0	0	0
Rental income	286,353	227,531	812,435	590,426
Interest income	0	0	2,111	0
Other income	284	1,118	875	3,248
Total revenues	286,637	228,649	815,421	593,674
Property operating expenses	8,227	9,345	25,697	30,657
Consolidated net operating income (loss)	278,410	219,304	789,724	563,017
Operating Segments | Outpatient Medical
Segment Reporting Information [Line Items]
Resident fees and services	0	0	0	0
Rental income	213,122	202,955	631,647	593,523
Interest income	0	0	0	0
Other income	2,050	2,040	6,352	7,019
Total revenues	215,172	204,995	637,999	600,542
Property operating expenses	63,319	62,778	190,759	186,426
Consolidated net operating income (loss)	151,853	142,217	447,240	414,116
Non-segment/Corporate
Segment Reporting Information [Line Items]
Resident fees and services	0	0	0	0
Rental income	0	0	0	0
Interest income	67,216	69,046	189,652	185,163
Other income	46,552	38,951	100,233	89,777
Total revenues	113,768	107,997	289,885	274,940
Property operating expenses	6,287	4,691	15,517	13,688
Consolidated net operating income (loss)	$ 107,481	$ 103,306	$ 274,368	$ 261,252