Dispositions, Real Property Held for Sale and Impairment - Narrative (Details) $ in Thousands	1 Months Ended	3 Months Ended				12 Months Ended
	Jun. 30, 2023 property	Mar. 31, 2024 USD ($) property	Sep. 30, 2023 property	Jun. 30, 2023 property	Mar. 31, 2023 USD ($) property	Dec. 31, 2023 USD ($) property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real estate held-for-sale | $		$ 422,225				$ 372,883	[1]
Expected sale proceeds | $		611,468
Impairment of assets held for sale | $		15,584			$ 12,629
Impairment of assets held for use | $		3,952
Revera Joint Venture, Disposal Transaction
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Property sold | property	4		13	31		14
Held for sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Secured debt | $		171,292
Net other assets and liabilities | $		21,925
Sold or Held for sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) from real estate dispositions, net | $		$ (37,190)			$ (14,525)
Seniors Housing Operating
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Properties classified as held for sale | property		21			3
Property sold | property		4
Impairment of assets sold | $		$ 23,795
Properties sold, impaired | property		2
Properties held for sale and not yet sold | property		6
Number of properties held for use | property		2			1
Triple-net
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Properties classified as held for sale | property		1
Outpatient Medical
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Properties classified as held for sale | property		4

[1] The consolidated balance sheet at December 31, 2023 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by U.S. generally accepted accounting principles for complete financial statements.