Real Property Acquisitions and Development - Summary of Real Property Investment Activity by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Land and land improvements	$ 603,017	$ 117,466	$ 472,500
Buildings and improvements	3,470,801	780,048	3,676,958
Acquired lease intangibles	289,340	53,386	259,930
Real property held for sale			17,435
Construction in progress			36,174
Right of use assets, net	77,455		58,377
Total net real estate assets	4,440,613	950,900	4,521,374
Receivables and other assets	10,041	1,014	17,220
Total assets acquired	4,450,654	951,914	4,538,594
Secured debt			(401,162)
Lease liabilities	(138,126)		(47,740)
Accrued expenses and other liabilities	(200,423)	(2,612)	(44,917)
Total liabilities acquired	(338,549)	(2,612)	(493,819)
Noncontrolling interests	(27,931)	(45,546)	(73,203)
Non-cash acquisition related activity			(11,889)
Cash disbursed for acquisitions	4,084,174	903,756	3,959,683
Construction in progress additions	441,926	220,034	349,316
Less: Capitalized interest	(19,352)	(17,472)	(15,272)
Accruals	(4,611)	(1,226)	(1,035)
Cash disbursed for construction in progress	417,963	201,336	333,009
Capital improvements to existing properties	282,588	244,989	328,824
Total cash invested in real property, net of cash acquired	4,784,725	1,350,081	4,621,516
Cash acquired from acquisition	4,201	580	2,090
Seniors Housing Operating
Business Acquisition [Line Items]
Land and land improvements	449,335	55,000	154,470
Buildings and improvements	2,347,609	527,189	1,518,748
Acquired lease intangibles	264,589	28,668	76,009
Real property held for sale			17,435
Construction in progress			36,174
Right of use assets, net	77,455		0
Total net real estate assets	3,138,988	610,857	1,802,836
Receivables and other assets	6,096	746	15,634
Total assets acquired	3,145,084	611,603	1,818,470
Secured debt			(194,408)
Lease liabilities	(138,126)		0
Accrued expenses and other liabilities	(191,454)	(1,650)	(12,024)
Total liabilities acquired	(329,580)	(1,650)	(206,432)
Noncontrolling interests	(4,942)	(45,546)	(67,987)
Non-cash acquisition related activity			(11,889)
Cash disbursed for acquisitions	2,810,562	564,407	1,532,162
Construction in progress additions	322,050	134,945	227,018
Less: Capitalized interest	(13,834)	(10,389)	(8,889)
Accruals	35	(1,226)	0
Cash disbursed for construction in progress	308,251	123,330	218,129
Capital improvements to existing properties	197,829	107,379	260,413
Total cash invested in real property, net of cash acquired	3,316,642	795,116	2,010,704
Triple-net
Business Acquisition [Line Items]
Land and land improvements	88,839	16,876	24,097
Buildings and improvements	809,328	73,855	203,282
Acquired lease intangibles	0	0	0
Real property held for sale			0
Construction in progress			0
Right of use assets, net	0		0
Total net real estate assets	898,167	90,731	227,379
Receivables and other assets	411	0	0
Total assets acquired	898,578	90,731	227,379
Secured debt			0
Lease liabilities	0		0
Accrued expenses and other liabilities	(8,703)	0	0
Total liabilities acquired	(8,703)	0	0
Noncontrolling interests	(6,449)	0	(4,015)
Non-cash acquisition related activity			0
Cash disbursed for acquisitions	883,426	90,731	223,364
Construction in progress additions	77,412	45,256	61,414
Less: Capitalized interest	(3,078)	(3,209)	(2,385)
Accruals	0	0	0
Cash disbursed for construction in progress	74,334	42,047	59,029
Capital improvements to existing properties	37,345	76,625	17,426
Total cash invested in real property, net of cash acquired	995,105	209,403	299,819
Outpatient Medical
Business Acquisition [Line Items]
Land and land improvements	64,843	45,590	293,933
Buildings and improvements	313,864	179,004	1,954,928
Acquired lease intangibles	24,751	24,718	183,921
Real property held for sale			0
Construction in progress			0
Right of use assets, net	0		58,377
Total net real estate assets	403,458	249,312	2,491,159
Receivables and other assets	3,534	268	1,586
Total assets acquired	406,992	249,580	2,492,745
Secured debt			(206,754)
Lease liabilities	0		(47,740)
Accrued expenses and other liabilities	(266)	(962)	(32,893)
Total liabilities acquired	(266)	(962)	(287,387)
Noncontrolling interests	(16,540)	0	(1,201)
Non-cash acquisition related activity			0
Cash disbursed for acquisitions	390,186	248,618	2,204,157
Construction in progress additions	42,464	39,833	60,884
Less: Capitalized interest	(2,440)	(3,874)	(3,998)
Accruals	(4,646)	0	(1,035)
Cash disbursed for construction in progress	35,378	35,959	55,851
Capital improvements to existing properties	47,414	60,985	50,985
Total cash invested in real property, net of cash acquired	$ 472,978	$ 345,562	$ 2,310,993