Leases and Management Agreements with Five Star - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue
Total revenues	$ 1,632,026	$ 1,040,155	$ 1,117,164
Residents fees and services
Disaggregation of Revenue
Total revenues	1,204,811	433,597	$ 416,523
Residents fees and services | Basic housing and support services
Disaggregation of Revenue
Total revenues	856,687	353,699
Residents fees and services | Medicare and Medicaid programs
Disaggregation of Revenue
Total revenues	173,878	31,324
Residents fees and services | Private pay and other third party payer SNF services
Disaggregation of Revenue
Total revenues	$ 174,246	$ 48,574