Segment Information (Details) $ in Thousands		12 Months Ended
	Jul. 01, 2021	Dec. 31, 2021 USD ($) segment	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment		3
Revenue		$ 2,758,259	$ 3,540,195	$ 4,057,088
Segment operating income		500,951	797,147	876,544
General and administrative expense (including non-cash stock-based compensation expense)		184,916	206,575	219,289
Facility operating lease expense		174,358	224,033	269,666
Depreciation and amortization		337,613	359,226	379,433
Asset impairment		23,003	107,308	49,266
Loss (gain) on facility operating lease termination, net		(2,003)	(2,303)	3,388
Income (loss) from operations		(216,936)	(97,692)	(44,498)
Total interest expense		195,140	208,779	248,341
Total capital expenditures for property, plant and equipment, and leasehold intangibles		182,718	181,105	295,201
Assets		6,410,467	6,901,758
Equity in earnings (loss) of unconsolidated ventures		10,394	(2,107)	(4,544)
CARES Act
Segment Reporting Information [Line Items]
Cash made available for Provider Relief Fund		$ 12,368	115,749
Health Care Services | Securities Purchase Agreement | HCA Healthcare, Inc.
Segment Reporting Information [Line Items]
Percentage of ownership sold in transaction	80.00%
Percentage of ownership after transaction	20.00%	20.00%
Operating segments | Independent Living
Segment Reporting Information [Line Items]
Revenue		$ 477,050	524,421	544,558
Segment operating income		146,108	182,813	203,741
Facility operating lease expense		42,162	60,445	81,680
Depreciation and amortization		74,922	70,803	81,745
Asset impairment		3,483	31,317	1,812
Total interest expense		45,209	44,682	46,713
Total capital expenditures for property, plant and equipment, and leasehold intangibles		36,992	47,889	78,831
Assets		1,349,341	1,419,838
Operating segments | Independent Living | CARES Act
Segment Reporting Information [Line Items]
Cash made available for Provider Relief Fund		1,512	11,823
Operating segments | Assisted Living and Memory Care
Segment Reporting Information [Line Items]
Revenue		1,595,684	1,753,861	1,815,938
Segment operating income		294,320	428,601	518,636
Facility operating lease expense		111,117	137,900	157,823
Depreciation and amortization		200,677	224,790	222,574
Asset impairment		14,384	61,640	32,229
Total interest expense		121,785	134,015	166,097
Total capital expenditures for property, plant and equipment, and leasehold intangibles		105,177	90,354	157,845
Assets		3,601,144	3,787,611
Operating segments | Assisted Living and Memory Care | CARES Act
Segment Reporting Information [Line Items]
Cash made available for Provider Relief Fund		5,963	62,585
Operating segments | CCRCs
Segment Reporting Information [Line Items]
Revenue		306,213	340,337	402,175
Segment operating income		34,109	53,180	72,072
Facility operating lease expense		15,932	20,406	24,248
Depreciation and amortization		37,891	38,426	44,163
Asset impairment		4,790	12,413	4,983
Total interest expense		18,756	19,928	27,426
Total capital expenditures for property, plant and equipment, and leasehold intangibles		19,086	18,709	33,535
Assets		693,386	738,121
Operating segments | CCRCs | CARES Act
Segment Reporting Information [Line Items]
Cash made available for Provider Relief Fund		1,788	18,454
Operating segments | Corporate and All Other
Segment Reporting Information [Line Items]
Revenue		202,043	531,879	847,157
Segment operating income		20,598	130,690	57,108
Facility operating lease expense		5,147	5,282	5,915
Depreciation and amortization		23,783	24,458	28,704
Asset impairment		0	0	7,578
Total interest expense		9,390	10,154	8,105
Total capital expenditures for property, plant and equipment, and leasehold intangibles		21,463	23,638	24,506
Assets		766,596	723,010
Equity in earnings (loss) of unconsolidated ventures		17,200	67,200	329,900
Operating segments | Health Care Services
Segment Reporting Information [Line Items]
Revenue		177,269	389,697	447,260
Segment operating income		5,816	1,863	24,987
Depreciation and amortization		340	749	2,247
Asset impairment		346	1,938	2,664
Total capital expenditures for property, plant and equipment, and leasehold intangibles		0	515	$ 484
Assets		0	233,178
Operating segments | Health Care Services | CARES Act
Segment Reporting Information [Line Items]
Cash made available for Provider Relief Fund		$ 3,105	$ 22,887