Quarterly report pursuant to Section 13 or 15(d)

Real Estate Joint Ventures (Details)

v3.8.0.1
Real Estate Joint Ventures (Details)
$ in Thousands
1 Months Ended 9 Months Ended
Jul. 31, 2017
USD ($)
Sep. 30, 2017
USD ($)
buillding
Property
Sep. 30, 2016
USD ($)
Dec. 31, 2016
USD ($)
Investments in consolidated real estate joint ventures        
Due to Affiliate   $ 7,860 $ 14,329  
Real estate equity method investments   2,413   $ 2,355
GI-COPT        
Investments in consolidated real estate joint ventures        
Real estate equity method investments   25,200    
Difference between cost basis and our share of the underlying equity   17,100    
Consolidated real estate joint ventures        
Investments in consolidated real estate joint ventures        
Total Assets   300,087    
Encumbered Assets   122,187    
Total Liabilities   $ 120,805    
Variable Interest Entity, Primary Beneficiary | LW Redstone Company, LLC        
Investments in consolidated real estate joint ventures        
Ownership (as a percent)   85.00%    
Total Assets   $ 158,937    
Encumbered Assets   76,374    
Total Liabilities   $ 50,344    
Variable Interest Entity, Primary Beneficiary | M Square Associates, LLC        
Investments in consolidated real estate joint ventures        
Ownership (as a percent)   50.00%    
Total Assets   $ 70,767    
Encumbered Assets   45,813    
Total Liabilities   $ 46,895    
Variable Interest Entity, Primary Beneficiary | Stevens Investors, LLC        
Investments in consolidated real estate joint ventures        
Ownership (as a percent)   95.00%    
Total Assets   $ 70,383    
Encumbered Assets   0    
Total Liabilities   $ 23,566    
Due to Affiliate $ 6,700      
Operating office properties        
Investments in consolidated real estate joint ventures        
Number of real estate properties | Property   159    
Single-tenant data centers | Operating office properties        
Investments in consolidated real estate joint ventures        
Number of real estate properties | buillding   15    
Single-tenant data centers | Operating office properties | GI-COPT        
Investments in consolidated real estate joint ventures        
Ownership percentage (percent)   50.00%    
Number of real estate properties | Property   6