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Fair value portion of assets classified as held for sale.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Value of input used to measure investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of realized gain (loss) from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Number of shares of investment owned.

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Fair value portion of investments in an entity not consolidated. Includes, but is not limited to, investments in an entity that is affiliated with the reporting entity by means of direct or indirect ownership, an entity in which the reporting entity shares control of the entity with another party or group, an entity which the company has significant influence, but does not have control and subsidiaries that are not required to be consolidated and are accounted for using the equity or cost method.

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- Definition

The number of real estate properties owned as of the balance sheet date.

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Fair Value of Assets and Liabilities - Assets and Liabilities (Details) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
	Feb. 02, 2023 $ / shares shares	Sep. 30, 2023 USD ($) property	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) property	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Jun. 28, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Gains and (losses) on equity securities, net		$ 0	$ (2,674)	$ 8,126	$ (21,384)
Impairment of assets		$ 1,156	$ 0	$ 18,380	$ 0
Number of properties \| property		376		376
Disposal Group, Held-for-Sale, Not Discontinued Operations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Number of properties \| property		6		6
AlerisLife Inc
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Investment owned balance per shares \| $ / shares	$ 1.31
Corporate Joint Venture
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Number of properties \| property		11		11
Corporate Joint Venture \| Seaport Innovation LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Equity method investment ownership percentage		10.00%		10.00%			20.00%	55.00%
Holding period				10 years
Number of properties \| property		1		1
Corporate Joint Venture \| Seaport Innovation LLC \| Measurement Input, Discount Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Measurement input		0.0650		0.0650
Corporate Joint Venture \| Seaport Innovation LLC \| Measurement Input, Market Capitalization Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Measurement input		0.0600		0.0600
Corporate Joint Venture \| The LSMD Fund REIT LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Equity method investment ownership percentage		20.00%		20.00%
Holding period				10 years
Number of properties \| property		10		10
Corporate Joint Venture \| The LSMD Fund REIT LLC \| Measurement Input, Discount Rate \| Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Measurement input		0.0625		0.0625
Corporate Joint Venture \| The LSMD Fund REIT LLC \| Measurement Input, Discount Rate \| Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Measurement input		0.0800		0.0800
Corporate Joint Venture \| The LSMD Fund REIT LLC \| Measurement Input, Market Capitalization Rate \| Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Measurement input		0.0475		0.0475
Corporate Joint Venture \| The LSMD Fund REIT LLC \| Measurement Input, Market Capitalization Rate \| Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Measurement input		0.0700		0.0700
Recurring Fair Value Measurements Assets \| Level 1 \| Carrying Amount \| AlerisLife Inc
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Investments in affiliates, fair value		$ 0		$ 0		$ 5,880
Equity securities investment (in shares) \| shares	10,691,658
Recurring Fair Value Measurements Assets \| Level 1 \| Estimated Fair Value \| AlerisLife Inc
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Investments in affiliates, fair value		0		0		5,880
Recurring Fair Value Measurements Assets \| Level 3 \| Joint Venture \| Carrying Amount \| Seaport Innovation LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Investments in affiliates, fair value		107,773		107,773		104,697
Recurring Fair Value Measurements Assets \| Level 3 \| Joint Venture \| Carrying Amount \| The LSMD Fund REIT LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Investments in affiliates, fair value		45,971		45,971		50,780
Recurring Fair Value Measurements Assets \| Level 3 \| Joint Venture \| Estimated Fair Value \| Seaport Innovation LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Investments in affiliates, fair value		107,773		107,773		104,697
Recurring Fair Value Measurements Assets \| Level 3 \| Joint Venture \| Estimated Fair Value \| The LSMD Fund REIT LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Investments in affiliates, fair value		45,971		45,971		50,780
Non-Recurring Fair Value Measurements Assets \| Life Science Property
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Aggregate sales price		5,845		$ 5,845
Non-Recurring Fair Value Measurements Assets \| Life Science Property \| Disposal Group, Held-for-Sale, Not Discontinued Operations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Impairment of assets		$ 427
Number of properties \| property		1		1
Non-Recurring Fair Value Measurements Assets \| Senior Living Communities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Aggregate sales price		$ 741		$ 741
Non-Recurring Fair Value Measurements Assets \| Senior Living Communities \| Disposal Group, Held-for-Sale, Not Discontinued Operations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Impairment of assets		$ 729
Number of properties \| property		1		1
Non-Recurring Fair Value Measurements Assets \| Level 2 \| Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Real estate properties held for sale		$ 6,586		$ 6,586		0
Non-Recurring Fair Value Measurements Assets \| Level 2 \| Estimated Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Real estate properties held for sale		$ 6,586		$ 6,586		$ 0