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- Definition

Real Estate Owned, Property Management And Construction Supervision Fees

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Related Party Transaction, Common Shares Ownership Percentage

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Related Party Transaction, Shares Owned By Related Party

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- Definition

Shares To Purchase Through Rights Offering Percentage

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- Definition

Number of mortgage loans within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

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Amount of investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

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- Definition

The percentage charged for managing real estate properties.

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- Definition

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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Cash received on stock transaction after deduction of issuance costs.

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The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

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Percentage of subsidiary's or equity investee's stock owned by parent company after stock transaction.

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Related Person Transactions (Details) $ in Thousands					1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
Related Person Transactions (Details) $ in Thousands	Dec. 11, 2025 shares	Dec. 04, 2025 shares	Nov. 10, 2025 USD ($) loan	Oct. 30, 2025 USD ($) shares	Jul. 31, 2023	Jun. 30, 2026 USD ($) shares	Jun. 30, 2025 USD ($)	Jun. 30, 2026 USD ($) loan shares	Jun. 30, 2025 USD ($)	Dec. 31, 2025 USD ($) loan	Mar. 31, 2026 USD ($)	Mar. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)
Related Party Transaction [Line Items]
Number of loans \| loan								27		24
Amortized cost \| $						$ 719,634	$ 631,318	$ 719,634	$ 631,318	$ 685,707	$ 730,096	$ 660,237	$ 609,916
Tremont Realty Advisors LLC \| Transferrable Rights Offering
Related Party Transaction [Line Items]
Sale of stock, percentage of ownership after transaction (as a percent)								20.20%
Shares issued (in shares)	2,015,748	854,029
Adam Portnoy \| Transferrable Rights Offering
Related Party Transaction [Line Items]
Shares owned (in shares)						5,095,308		5,095,308
Shares issued (in shares)		109,669
The RMR Group Inc
Related Party Transaction [Line Items]
Property management agreement, termination notice period (in days)					30 days
Real estate owned, property management and construction supervision fees \| $						$ 18	$ 16	$ 38	$ 37
The RMR Group Inc \| Transferrable Rights Offering
Related Party Transaction [Line Items]
Shares owned (in shares)				5,517,113
Sale of stock, percentage of ownership after transaction (as a percent)				73.20%
Shares issued (in shares)				7,532,861
Net proceeds \| $				$ 65,200
Rights offering percentage (as a percent)				100.00%
ABP Trust \| Transferrable Rights Offering
Related Party Transaction [Line Items]
Shares issued (in shares)		58,266
Management Services \| Tremont Realty Advisors LLC
Related Party Transaction [Line Items]
Shares owned (in shares)						4,577,835		4,577,835
Outstanding common shares (as a percent)						22.50%		22.50%
Property Management Services \| The RMR Group Inc
Related Party Transaction [Line Items]
Property management fee (as a percent)					3.00%
Construction Supervision Services \| The RMR Group Inc
Related Party Transaction [Line Items]
Property management fee (as a percent)					5.00%
Purchase of Mortgage Loans
Related Party Transaction [Line Items]
Number of loans \| loan			2
Purchase of Mortgage Loans \| The RMR Group Inc
Related Party Transaction [Line Items]
Amortized cost \| $			$ 61,733