Annual report pursuant to Section 13 and 15(d)

Real Estate Joint Ventures (Unconsolidated Real Estate Joint Ventures) (Details)

v3.22.0.1
Real Estate Joint Ventures (Unconsolidated Real Estate Joint Ventures) (Details)
$ in Thousands
Dec. 31, 2021
USD ($)
property
Jun. 02, 2021
Dec. 31, 2020
USD ($)
Dec. 22, 2020
Oct. 30, 2020
Dec. 31, 2019
Unconsolidated Real Estate Joint Ventures            
Schedule of Equity Method Investments [Line Items]            
Number of real estate properties | property 19          
Real estate equity method investments $ 39,889   $ 29,303      
BRE-COPT 2            
Schedule of Equity Method Investments [Line Items]            
Nominal Ownership % 10.00%   10.00% 10.00% 10.00%  
Number of real estate properties | property 8          
Real estate equity method investments $ 15,579   $ 15,988      
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 from GI-COPT $ 7,200   7,400      
BREIT-COPT            
Schedule of Equity Method Investments [Line Items]            
Nominal Ownership % 10.00%         10.00%
Number of real estate properties | property 9          
Real estate equity method investments $ 12,460   13,315      
BRE-COPT 3            
Schedule of Equity Method Investments [Line Items]            
Nominal Ownership % 10.00% 10.00%        
Number of real estate properties | property 2          
Real estate equity method investments $ 11,850   $ 0