v3.26.1
Related Person Transactions - Narrative (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 9 Months Ended
Jun. 17, 2026
Jun. 05, 2015
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Apr. 30, 2026
Sep. 30, 2025
Related Party Transaction [Line Items]                
Separation costs     $ 1,720 $ 1,880 $ 4,392 $ 5,335    
Offering price per share (in usd per share)             $ 1.20  
Total revenues     45,526 44,068 154,269 136,965    
Total reimbursable costs     102,796 107,950 309,455 396,958    
Investments     136,200   136,200     $ 31,900
OPI                
Related Party Transaction [Line Items]                
Payment for investments   $ 53,415            
OPI                
Related Party Transaction [Line Items]                
Investments $ 8,778              
OPI | Common shares                
Related Party Transaction [Line Items]                
Common stock, par value (in usd per share) $ 0.01              
Shares owned (in shares) 439,072              
Shares received as percentage of outstanding shares 2.00%              
Additional hares received as percentage of outstanding shares 8.00%              
GOV and Select Income REIT                
Related Party Transaction [Line Items]                
Other impairment loss     19,066   19,066      
Investments     60,162   60,162      
Management services                
Related Party Transaction [Line Items]                
Total revenues     44,093 42,724 126,685 133,289    
Other reimbursable expenses                
Related Party Transaction [Line Items]                
Total reimbursable costs     $ 81,002 87,977 $ 249,913 333,882    
Common shares                
Related Party Transaction [Line Items]                
Common stock, par value (in usd per share)     $ 0.01   $ 0.01      
ABP Trust and Managed REIT                
Related Party Transaction [Line Items]                
Lease expense     $ 1,608 1,519 $ 4,333 4,251    
Abp Trust | Up C Transaction                
Related Party Transaction [Line Items]                
Tax receivable agreement, percent of payment         85.00%      
Liability related to tax receivable agreement     18,478   $ 18,478      
Current portion of liability related to tax receivable agreement     2,552   2,552      
Total revenues from related parties                
Related Party Transaction [Line Items]                
Total revenues     45,526 44,068 154,269 136,965    
Total reimbursable costs     102,796 107,950 309,455 396,958    
Total revenues from related parties | Former Nonexecutive Officer                
Related Party Transaction [Line Items]                
Separation costs     1,720 1,880 4,392 5,335    
Cash severance costs     1,252 1,741 3,871 4,919    
Equity severance costs     $ 468 $ 139 $ 521 $ 416    
RMR LLC                
Related Party Transaction [Line Items]                
Common stock, shares issued (in shares)             41,666,666  
Payments for common stock             $ 50,000  
Ownership percentage by related parties     6.40%   6.40%      
Adam Portnoy                
Related Party Transaction [Line Items]                
Ownership percentage by related parties     6.80%   6.80%      
OPI Management                
Related Party Transaction [Line Items]                
Agreement term 5 years 20 years            
Termination term 2 years              
Property management fee, percent fee 3.00%              
Construction supervision fee percentage 5.00%              
OPI Management | Management services                
Related Party Transaction [Line Items]                
Total revenues $ 14,000              
Termination term 2 years              
OPI Management | Other reimbursable expenses                
Related Party Transaction [Line Items]                
Total reimbursable costs     $ 950   $ 950