Quarterly report pursuant to Section 13 or 15(d)

Real Estate Joint Ventures - Investments in Unconsolidated Real Estate Joint Ventures (Details)

v3.22.2.2
Real Estate Joint Ventures - Investments in Unconsolidated Real Estate Joint Ventures (Details)
$ in Thousands
Sep. 30, 2022
USD ($)
property
Dec. 31, 2021
USD ($)
Unconsolidated Real Estate Joint Ventures    
Schedule of Equity Method Investments [Line Items]    
Number of Properties | property 19  
Carrying value of Investments $ 38,644 $ 39,889
B RE COPT DC JV II LLC    
Schedule of Equity Method Investments [Line Items]    
Nominal Ownership % 10.00%  
Number of Properties | property 8  
Carrying value of Investments $ 15,140 15,579
Difference between the joint venture's cost basis and the entity's share of B RE COPT’s underlying equity in the net assets acquired $ 7,100 7,200
BREIT COPT DC JV LLC    
Schedule of Equity Method Investments [Line Items]    
Nominal Ownership % 10.00%  
Number of Properties | property 9  
Carrying value of Investments $ 11,801 12,460
B RE COPT DC JV III LLC    
Schedule of Equity Method Investments [Line Items]    
Nominal Ownership % 10.00%  
Number of Properties | property 2  
Carrying value of Investments $ 11,703 $ 11,850