v3.26.1
Cover Page - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
May 18, 2026
Jun. 30, 2025
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2025    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 001-34364    
Entity Registrant Name OFFICE PROPERTIES INCOME TRUST    
Entity Incorporation, State or Country Code MD    
Entity Tax Identification Number 26-4273474    
Entity Address, Address Line One Two Newton Place,    
Entity Address, Address Line Two 255 Washington Street,    
Entity Address, Address Line Three Suite 300,    
Entity Address, City or Town Newton,    
Entity Address, State or Province MA    
Entity Address, Postal Zip Code 02458-1634    
City Area Code 617    
Local Phone Number 219-1440    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Public Float     $ 18.2
Entity Common Stock, Shares Outstanding   73,941,128  
Documents Incorporated by Reference
References in this Annual Report on Form 10-K to the Company, OPI, we, us or our mean Office Properties Income Trust and its consolidated subsidiaries unless otherwise expressly stated or the context indicates otherwise.
    
Entity Central Index Key 0001456772    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Amendment Flag false