| Cover Page | Jun. 24, 2021 |
| Entity Information [Line Items] | |
| Document Type | 8-K/A |
| Document Period End Date | Jun. 24, 2021 |
| Entity Registrant Name | OFFICE PROPERTIES INCOME TRUST |
| Entity Incorporation, State or Country Code | MD |
| Entity File Number | 001-34364 |
| 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 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001456772 |
| Amendment Flag | true |
| Amendment Description | On June 28, 2021, we filed a Current Report on Form 8-K, or the Original Form 8-K, to report that a subsidiary of ours acquired an office property located at 1000 West Fulton Market Street in Chicago, IL, with approximately 531,000 rentable square feet, or 1K Fulton, for $355.0 million, excluding purchase price adjustments and acquisition related costs, from SVF Fulton Chicago, LLC, an unaffiliated third party. We are amending the Original Form 8-K to provide the historical financial statements required by Item 9.01(a) of Form 8-K and to provide the pro forma financial information required by Item 9.01(b) of Form 8-K, which financial statements and pro forma information were not included in the Original Form 8-K as permitted by Item 9.01(a)(3) and Item 9.01(b)(2) of Form 8-K. This amendment reports no other updates or amendments to the Original Form 8-K. |
| Common Shares Of Beneficial Interest | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Common Shares of Beneficial Interest |
| Trading Symbol | OPI |
| Security Exchange Name | NASDAQ |
| 6.375% Senior Notes due 2050 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | 6.375% Senior Notes due 2050 |
| Trading Symbol | OPINL |
| Security Exchange Name | NASDAQ |
