Business and Property Management Agreements with RMR-Schedule of Business Management Fees, Property Management Fees and Construction Supervision Fees Recognized (Details) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Pursuant to business management agreement:
Incentive management fees	$ 17,905,000	$ 0	$ 0
RMR LLC
Pursuant to business management agreement:
Business management fees	15,761,000	16,468,000	13,965,000
Incentive management fees	17,905,000	0	0
Total business management fees and incentive management fees	33,666,000	16,468,000	13,965,000
Pursuant to property management agreement
Property management fees	4,816,000	5,683,000	5,686,000
Construction supervision fees	1,063,000	2,005,000	3,200,000
Total property management and construction supervision fees	5,879,000	7,688,000	8,886,000
Expense Reimbursement:
Property level expenses	13,193,000	15,023,000	14,587,000
Recognized amortization of the liability	2,974,000	2,974,000	2,974,000
Amortization of liability related to property management and construction supervision fees	797,000	797,000	797,000
RMR LLC | General and administrative expenses
Expense Reimbursement:
Other expenses	200,000	304,000	288,000
RMR LLC | Property operating expenses
Expense Reimbursement:
Property level expenses	$ 12,993,000	$ 14,719,000	$ 14,299,000