Dispositions, Real Property Held for Sale and Impairment - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) property	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) property	Sep. 30, 2022 USD ($) property	Dec. 31, 2022 USD ($)	[1]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real estate held-for-sale | $	$ 355,380,000		$ 355,380,000		$ 133,058,000
Expected sale proceeds | $			518,443,000
Impairment of assets held for sale | $			15,401,000	$ 4,356,000
Impairment of assets held for use | $			5,702,000
Held for sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Secured debt | $	166,312,000		166,312,000
Net other assets and liabilities | $	37,072,000		37,072,000
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 | $	$ 1,482,000	$ (633,000)	$ 53,479,000	$ 990,000
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	18		18
Number of properties held for sale, impaired | property	4		4
Number of properties held for use | property			2
Outpatient Medical
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Properties classified as held for sale | property	2		2
Number of properties held for use | property				1
Triple-net
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties held for sale, impaired | property	1		1
Number of properties held for use | property			1	2

[1] The consolidated balance sheet at December 31, 2022 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.