Quarterly report pursuant to Section 13 or 15(d)

Real Estate Joint Ventures - Narrative (Details)

v3.21.2
Real Estate Joint Ventures - Narrative (Details)
$ in Millions
Aug. 11, 2021
USD ($)
Sep. 30, 2021
USD ($)
Jun. 02, 2021
property
Stevens Investors, LLC | Construction Loan      
Real Estate [Line Items]      
Related party transaction, amount of transaction $ 112.0    
Loans and leases receivable, related parties   $ 90.5  
B RE COPT DC JV III LLC      
Real Estate [Line Items]      
Nominal Ownership %   10.00% 10.00%
Disposed of by sale | Data Center Shells in Northern Virginia      
Real Estate [Line Items]      
Ownership percentage sold     90.00%
Number of real estate properties sold | property     2
London Interbank Offered Rate (LIBOR) | Stevens Investors, LLC | Construction Loan      
Real Estate [Line Items]      
Related party transaction, rate 2.35%