Segment Information (Details) $ in Thousands		12 Months Ended
	Jul. 01, 2021	Dec. 31, 2023 USD ($) segment	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment		3
Revenue		$ 3,015,829	$ 2,825,379	$ 2,758,259
Segment operating income		746,704	594,413	500,951
General and administrative expense (including non-cash stock-based compensation expense)		178,894	168,594	184,916
Facility operating lease expense		202,410	165,294	174,358
Depreciation and amortization		342,712	347,444	337,613
Asset impairment		40,572	29,618	23,003
Loss (gain) on sale of communities, net		(36,296)	(73,850)	0
Loss (gain) on facility operating lease termination, net		0	0	(2,003)
Income (loss) from operations		18,412	(42,687)	(216,936)
Total interest expense		238,274	204,717	195,140
Total capital expenditures for property, plant and equipment, and leasehold intangibles		228,592	200,009	182,718
Assets		5,573,435	5,937,062
Equity in earnings (loss) of unconsolidated ventures		(3,996)	(10,782)	10,394
Goodwill		27,321	27,321
CARES Act
Segment Reporting Information [Line Items]
Cash made available for Provider Relief Fund		9,073	80,469	12,368
Independent Living
Segment Reporting Information [Line Items]
Goodwill		27,300	27,300	27,300
Health Care Services | HCA Healthcare, Inc.
Segment Reporting Information [Line Items]
Percentage of ownership after transaction	20.00%
Operating segments | Independent Living
Segment Reporting Information [Line Items]
Revenue		564,499	518,699	477,050
Segment operating income		184,645	158,950	146,108
Facility operating lease expense		39,114	39,700	42,162
Depreciation and amortization		83,637	79,521	74,922
Asset impairment		1,647	10,893	3,483
Total interest expense		61,624	48,788	45,209
Total capital expenditures for property, plant and equipment, and leasehold intangibles		51,188	44,857	36,992
Assets		1,206,021	1,267,825
Operating segments | Independent Living | CARES Act
Segment Reporting Information [Line Items]
Cash made available for Provider Relief Fund		487	10,906	1,512
Operating segments | Assisted Living and Memory Care
Segment Reporting Information [Line Items]
Revenue		1,968,440	1,815,722	1,595,684
Segment operating income		502,317	379,958	294,320
Facility operating lease expense		146,166	106,961	111,117
Depreciation and amortization		196,994	207,344	200,677
Asset impairment		11,574	11,613	14,384
Total interest expense		141,330	133,139	121,785
Total capital expenditures for property, plant and equipment, and leasehold intangibles		121,240	111,978	105,177
Assets		3,315,921	3,329,516
Operating segments | Assisted Living and Memory Care | CARES Act
Segment Reporting Information [Line Items]
Cash made available for Provider Relief Fund		8,008	60,630	5,963
Operating segments | CCRCs
Segment Reporting Information [Line Items]
Revenue		333,404	331,577	306,213
Segment operating income		49,581	43,485	34,109
Facility operating lease expense		12,943	13,883	15,932
Depreciation and amortization		36,951	38,039	37,891
Asset impairment		1,368	5,970	4,790
Total interest expense		24,889	21,251	18,756
Total capital expenditures for property, plant and equipment, and leasehold intangibles		37,414	20,467	19,086
Assets		612,521	664,502
Operating segments | CCRCs | CARES Act
Segment Reporting Information [Line Items]
Cash made available for Provider Relief Fund		578	8,933	1,788
Operating segments | Corporate and All Other
Segment Reporting Information [Line Items]
Revenue		149,486	159,381	202,043
Segment operating income		10,161	12,020	20,598
Facility operating lease expense		4,187	4,750	5,147
Depreciation and amortization		25,130	22,540	23,783
Asset impairment		25,983	1,142	346
Total interest expense		10,431	1,539	9,390
Total capital expenditures for property, plant and equipment, and leasehold intangibles		18,750	22,707	21,463
Assets		438,972	675,219
Equity in earnings (loss) of unconsolidated ventures		$ 900	$ 4,200	17,200
Operating segments | Health Care Services
Segment Reporting Information [Line Items]
Revenue				177,269
Segment operating income				5,816
Depreciation and amortization				340
Operating segments | Health Care Services | CARES Act
Segment Reporting Information [Line Items]
Cash made available for Provider Relief Fund				$ 3,105