Acquisitions, Dispositions and Other Significant Transactions - CCRC Venture (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) community	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Distributions from unconsolidated ventures from cumulative share of net earnings	$ 6,191	$ 766	$ 3,472
Equity in earnings (loss) of unconsolidated ventures	10,394	(2,107)	(4,544)
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations | Communities Disposed of Through Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds	$ 16,500	$ 38,100	$ 85,400
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations | Communities Disposed of Through Sale | CCRC Venture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of entry fee communities sold | community	2
Cash proceeds	$ 14,000
Distributions from unconsolidated ventures from cumulative share of net earnings	8,300
Equity in earnings (loss) of unconsolidated ventures	$ 13,600