Segment Reporting - Summary Information for Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Segment Reporting Information [Line Items]
Resident fees and services	$ 2,780,931	$ 1,864,530
Rental income	453,842	461,567
Interest income	70,929	62,490
Other income	46,224	34,500
Total revenues	3,351,926	2,423,087
Property operating expenses	2,055,420	1,462,390
Consolidated net operating income (loss)	1,296,506	960,697
Depreciation and amortization	622,752	485,869
Interest expense	192,715	144,962
General and administrative expenses	67,474	63,758
Loss (gain) on derivatives and financial instruments, net	0	(3,210)
Loss (gain) on extinguishment of debt, net	727	6,156
Provision for loan losses, net	1,632	(2,007)
Impairment of assets	4,826	52,402
Other expenses	61,137	14,060
Income (loss) from continuing operations before income taxes and other items	345,243	198,707
Income tax (expense) benefit	(11,633)	5,519
Income (loss) from unconsolidated entities	(1,686)	1,263
Gain (loss) on real estate dispositions and acquisitions of controlling interests, net	420,400	51,777
Income (loss) from continuing operations	752,324	257,266
Net income (loss)	752,324	257,266
Seniors Housing Operating
Segment Reporting Information [Line Items]
Rental income	231,571	185,225
Operating Segments | Seniors Housing Operating
Segment Reporting Information [Line Items]
Resident fees and services	2,780,931	1,864,530
Rental income	0	0
Interest income	0	0
Other income	9,443	3,341
Total revenues	2,790,374	1,867,871
Property operating expenses	2,015,361	1,384,684
Consolidated net operating income (loss)	775,013	483,187
Operating Segments | Triple-net
Segment Reporting Information [Line Items]
Resident fees and services	0	0
Rental income	383,803	252,688
Interest income	8,077	2,111
Other income	232	231
Total revenues	392,112	255,030
Property operating expenses	7,806	8,818
Consolidated net operating income (loss)	384,306	246,212
Operating Segments | Outpatient Medical
Segment Reporting Information [Line Items]
Resident fees and services	0	0
Rental income	70,039	208,879
Interest income	0	0
Other income	1,093	2,137
Total revenues	71,132	211,016
Property operating expenses	17,833	64,606
Consolidated net operating income (loss)	53,299	146,410
Non-segment/Corporate
Segment Reporting Information [Line Items]
Resident fees and services	0	0
Rental income	0	0
Interest income	62,852	60,379
Other income	35,456	28,791
Total revenues	98,308	89,170
Property operating expenses	14,420	4,282
Consolidated net operating income (loss)	$ 83,888	$ 84,888