Quarterly report pursuant to Section 13 or 15(d)

Organization - Narrative (Details)

v3.22.2.2
Organization - Narrative (Details) - 9 months ended Sep. 30, 2022
ft² in Millions
property
ft²
a
shares
Corporate Office Properties, L.P. | Preferred Units        
Investments in real estate        
Limited partners' capital account, units outstanding (in units) | shares       0
COPT | Corporate Office Properties, L.P. | Common Units        
Investments in real estate        
Percentage ownership in operating partnership 98.00%      
Unconsolidated Real Estate Joint Ventures        
Investments in real estate        
Number of real estate properties 19      
Operating Properties        
Investments in real estate        
Number of real estate properties 188      
Area of real estate property (in sqft or acres) | ft²   22.1    
Operating Properties | Office Properties        
Investments in real estate        
Number of real estate properties 161      
Area of real estate property (in sqft or acres) | ft²   17.1    
Operating Properties | Single-tenant data centers        
Investments in real estate        
Number of real estate properties 27      
Area of real estate property (in sqft or acres) | ft²   5.0    
Operating Properties | Single-tenant data centers | Unconsolidated Real Estate Joint Ventures        
Investments in real estate        
Number of real estate properties 19      
Properties under development        
Investments in real estate        
Number of real estate properties 12      
Area of real estate property (in sqft or acres) | ft²   1.9    
Properties under development | Office Properties        
Investments in real estate        
Number of real estate properties 9      
Properties under development | Single-tenant data centers        
Investments in real estate        
Number of real estate properties 3      
Properties under development, partially-operational        
Investments in real estate        
Number of real estate properties 1      
Properties under development, expansions of fully operational properties        
Investments in real estate        
Number of real estate properties 1      
Land controlled for future development        
Investments in real estate        
Area of real estate property (in sqft or acres)   8.4 710  
Other Land        
Investments in real estate        
Area of real estate property (in sqft or acres) | a     43