Supplemental Disclosure of Cash Flow Information - Narrative (Details) $ in Thousands		9 Months Ended		12 Months Ended		21 Months Ended	27 Months Ended
	May 01, 2023 USD ($) community	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2023 USD ($) community	Sep. 30, 2023 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of communities acquired | community						1
Number of equity interest communities acquired | community						1
Proceeds from sale of assets, net		$ 43,181	$ 5,844
Non-operating gain (loss) on sale of assets, net		37,156	611
Property, plant and equipment and leasehold intangibles, net		4,372,072		$ 4,535,702		$ 4,372,072	$ 4,372,072
Employee retention credit, amount received		$ 14,700	$ 1,200
CARES Act
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Employee retention credit, amount recognized				$ 9,400	$ 9,900
Employee retention credit, amount received							$ 19,300
One Acquired Community
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage		50.00%				50.00%	50.00%
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of communities disposed of | community						3
Communities Disposed of Through Lease Terminations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of communities disposed of | community						4
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations | CCRCs Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of entry fee communities sold | community	1
Proceeds from sale of assets, net	$ 12,700
Property, plant and equipment and leasehold intangibles, net		$ 12,700				$ 12,700	$ 12,700
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations | CCRCs Segment | Secured Debt | Mortgages
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Current portion of long-term debt	29,600
Non-operating gain (loss) on sale of assets, net	$ 36,300