Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 1,014,139	$ 1,042,044
Private pay
Disaggregation of Revenue [Line Items]
Revenue	640,776	648,679
Government reimbursement
Disaggregation of Revenue [Line Items]
Revenue	110,532	127,408
Other third-party payor programs
Disaggregation of Revenue [Line Items]
Revenue	31,399	33,392
Total resident fee revenue
Disaggregation of Revenue [Line Items]
Revenue	782,707	809,479
Independent Living | Private pay
Disaggregation of Revenue [Line Items]
Revenue	135,290	135,045
Independent Living | Government reimbursement
Disaggregation of Revenue [Line Items]
Revenue	572	649
Independent Living | Other third-party payor programs
Disaggregation of Revenue [Line Items]
Revenue	0	0
Independent Living | Total resident fee revenue
Disaggregation of Revenue [Line Items]
Revenue	135,862	135,694
Assisted Living and Memory Care | Private pay
Disaggregation of Revenue [Line Items]
Revenue	440,613	441,911
Assisted Living and Memory Care | Government reimbursement
Disaggregation of Revenue [Line Items]
Revenue	16,866	16,615
Assisted Living and Memory Care | Other third-party payor programs
Disaggregation of Revenue [Line Items]
Revenue	0	0
Assisted Living and Memory Care | Total resident fee revenue
Disaggregation of Revenue [Line Items]
Revenue	457,479	458,526
CCRCs | Private pay
Disaggregation of Revenue [Line Items]
Revenue	64,703	71,533
CCRCs | Government reimbursement
Disaggregation of Revenue [Line Items]
Revenue	19,405	21,487
CCRCs | Other third-party payor programs
Disaggregation of Revenue [Line Items]
Revenue	10,439	10,707
CCRCs | Total resident fee revenue
Disaggregation of Revenue [Line Items]
Revenue	94,547	103,727
Health Care Services | Private pay
Disaggregation of Revenue [Line Items]
Revenue	170	190
Health Care Services | Government reimbursement
Disaggregation of Revenue [Line Items]
Revenue	73,689	88,657
Health Care Services | Other third-party payor programs
Disaggregation of Revenue [Line Items]
Revenue	20,960	22,685
Health Care Services | Total resident fee revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 94,819	$ 111,532