Leases and Management Agreements with Five Star - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue
Revenues	$ 337,416	$ 394,339	$ 1,046,481	$ 1,247,117
Residents fees and services
Disaggregation of Revenue
Revenues	236,013	290,101	739,926	926,174
Residents fees and services | Basic housing and support services
Disaggregation of Revenue
Revenues	188,381	208,941	564,579	659,240
Residents fees and services | Medicare and Medicaid programs
Disaggregation of Revenue
Revenues	18,948	38,882	79,803	131,460
Residents fees and services | Private pay and other third party payer SNF services
Disaggregation of Revenue
Revenues	$ 28,684	$ 42,278	$ 95,544	$ 135,474