Organization - Narrative 2 (Details) - Corporate Office Properties, L.P.  | 
6 Months Ended | 
|---|---|
| 
 Jun. 30, 2022  
shares 
 | |
| Preferred Units | |
| Forms of ownership in Operating Partnership and ownership percentage by the entity | |
| Limited partners' capital account, units outstanding (in units) | 0 | 
| COPT | Common Units | |
| Forms of ownership in Operating Partnership and ownership percentage by the entity | |
| Percentage ownership in operating partnership | 98.00% | 
| X | ||||||||||
- Definition Line items related to the percentage of classes of ownership in a subsidiary that are owned by the parent. No definition available. 
  | 
| X | ||||||||||
- Definition Percentage investment held by the managing member or general partner of the limited liability company (LLC) or limited partnership (LP). Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
  | 
| X | ||||||||||
- Definition The number of limited partner units outstanding. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
  | 
| X | ||||||||||
- Details 
  | 
| X | ||||||||||
- Details 
  | 
| X | ||||||||||
- Details 
  | 
| X | ||||||||||
- Details 
  |