Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 2,758,259	$ 3,540,195	$ 4,057,088
Resident fees
Disaggregation of Revenue [Line Items]
Revenue	2,543,848	2,892,567	3,209,931
Private pay
Disaggregation of Revenue [Line Items]
Revenue	2,208,910	2,368,295	2,572,426
Government reimbursement
Disaggregation of Revenue [Line Items]
Revenue	261,376	418,629	509,037
Other third-party payor programs
Disaggregation of Revenue [Line Items]
Revenue	73,562	105,643	128,468
Independent Living | Resident fees
Disaggregation of Revenue [Line Items]
Revenue	475,538	512,598	544,558
Independent Living | Private pay
Disaggregation of Revenue [Line Items]
Revenue	473,740	510,254	542,112
Independent Living | Government reimbursement
Disaggregation of Revenue [Line Items]
Revenue	1,798	2,344	2,446
Independent Living | Other third-party payor programs
Disaggregation of Revenue [Line Items]
Revenue	0	0	0
Assisted Living and Memory Care | Resident fees
Disaggregation of Revenue [Line Items]
Revenue	1,589,721	1,691,276	1,815,938
Assisted Living and Memory Care | Private pay
Disaggregation of Revenue [Line Items]
Revenue	1,521,588	1,622,117	1,748,364
Assisted Living and Memory Care | Government reimbursement
Disaggregation of Revenue [Line Items]
Revenue	68,133	69,159	67,574
Assisted Living and Memory Care | Other third-party payor programs
Disaggregation of Revenue [Line Items]
Revenue	0	0	0
CCRCs | Resident fees
Disaggregation of Revenue [Line Items]
Revenue	304,425	321,883	402,175
CCRCs | Private pay
Disaggregation of Revenue [Line Items]
Revenue	212,981	235,018	281,197
CCRCs | Government reimbursement
Disaggregation of Revenue [Line Items]
Revenue	57,362	59,614	81,054
CCRCs | Other third-party payor programs
Disaggregation of Revenue [Line Items]
Revenue	34,082	27,251	39,924
Health Care Services | Resident fees
Disaggregation of Revenue [Line Items]
Revenue	174,164	366,810	447,260
Health Care Services | Private pay
Disaggregation of Revenue [Line Items]
Revenue	601	906	753
Health Care Services | Government reimbursement
Disaggregation of Revenue [Line Items]
Revenue	134,083	287,512	357,963
Health Care Services | Other third-party payor programs
Disaggregation of Revenue [Line Items]
Revenue	$ 39,480	$ 78,392	$ 88,544