COVID-19 Pandemic (Details) $ in Thousands		1 Months Ended	3 Months Ended	6 Months Ended
	Jul. 26, 2020 USD ($) community	Mar. 31, 2020 USD ($) transaction community	Jun. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Subsequent Event [Line Items]
Line of credit, borrowings outstanding			$ 166,381	$ 166,381	$ 0
Capital expenditures incurred but not yet paid				50,000
Aggregate minimum rent amount			1,878,787	1,878,787
Rent reduced the next twelve months			287,241	287,241
Total liquidity			600,200	600,200
Unrestricted cash and cash equivalents			452,441	452,441	$ 240,227
Marketable securities			109,900	109,900
Number of non-recourse mortgage debt financing transactions | transaction		3
Payments of financing costs		$ 208,500
Number of communities acquired | community		26
Debt remaining 2020			36,400	36,400
Debt remaining 2021			254,100	254,100
CARES Act
Subsequent Event [Line Items]
Facility operating expense			60,600	70,600
Non-cash asset impairment charges			10,300	87,000
Employer portion of payroll taxes delayed			26,500	26,500
Income recognized from Emergency Fund grant			26,400
Unrecognized grants			7,100	7,100
Net grants received from Emergency Fund			33,500	33,500
CARES Act | Accelerated and Advance Payment Program
Subsequent Event [Line Items]
Amount received from Accelerated and Advance Payment Program			$ 85,000	$ 85,000
Percent of Medicare advanced payment			100.00%	100.00%
Repayment period start (in days)				120 days
Repayment period (in days)				210 days
Health Care Services and CCRCs | CARES Act
Subsequent Event [Line Items]
Cash made available for Emergency Fund			$ 28,800
Nursing Facilities | CARES Act
Subsequent Event [Line Items]
Cash made available for Emergency Fund			4,700
Line of Credit | Fifth Amended and Restated Credit Agreement
Subsequent Event [Line Items]
Line of credit, borrowings outstanding		$ 166,400	166,400	$ 166,400
Line of Credit | Fifth Amended and Restated Credit Agreement | Revolving Credit Facility
Subsequent Event [Line Items]
Line of credit facility, remaining borrowing capacity			37,900	$ 37,900
Subsequent Event | Ventas, Inc
Subsequent Event [Line Items]
Capital expenditures incurred but not yet paid	$ 37,800
Number of communities leased | community	120
Payments for Advance to Affiliate	$ 119,200
Aggregate minimum rent amount	100,000
Rent reduced the next twelve months	$ 86,000
Loans Insured or Guaranteed by US Government Authorities | CARES Act
Subsequent Event [Line Items]
Relief received from the Emergency Fund			$ 33,500