Quarterly report pursuant to Section 13 or 15(d)

Properties, Net (Details 6)

v3.5.0.2
Properties, Net (Details 6)
ft² in Thousands, $ in Thousands
 9 Months Ended
Jul. 21, 2016
USD ($)
Property
Sep. 30, 2016
USD ($)
ft²
buillding
Property
Sep. 30, 2015
USD ($)
Construction and Redevelopment Activities      
Value of properties contributed   $ 22,600 $ 0
Sale price of land   $ 5,700  
Operating office properties      
Construction and Redevelopment Activities      
Square footage of real estate properties (in square feet) | ft²   17,500  
Number of real estate properties | Property   168  
Office properties under, or contractually committed for, construction or approved for redevelopment      
Construction and Redevelopment Activities      
Square footage of real estate properties (in square feet) | ft²   1,200  
Number of real estate properties | Property   10  
Single-tenant data centers | Operating office properties      
Construction and Redevelopment Activities      
Transaction Value   $ 44,300  
Ownership percentage sold (percent) 50.00%    
Number of properties contributed | Property 6    
Value of properties contributed $ 147,600    
Proceeds from issuance of debt   $ 60,000  
Ownership percentage (percent) 50.00%    
Number of real estate properties | Property   12  
Newly constructed properties placed in service      
Construction and Redevelopment Activities      
Square feet of properties placed in service | ft²   490  
Number of real estate properties | Property   5  
Newly redeveloped properties placed in service      
Construction and Redevelopment Activities      
Square feet of properties placed in service | ft²   55  
Number of real estate properties | Property   2  
Properties under construction or contractually committed for construction      
Construction and Redevelopment Activities      
Square footage of real estate properties (in square feet) | ft²   1,100  
Number of real estate properties | Property   7  
Properties completed Held-for-future lease | Office properties under, or contractually committed for, construction or approved for redevelopment      
Construction and Redevelopment Activities      
Number of real estate properties | Property   2  
Properties under or approved for redevelopment      
Construction and Redevelopment Activities      
Square footage of real estate properties (in square feet) | ft²   104  
Number of real estate properties | Property   3  
Operating Properties      
Construction and Redevelopment Activities      
Number of Buildings | buillding   15  
Square footage of real estate properties (in square feet) | ft²   1,126  
Transaction Value   $ 210,713  
Gain on Disposition   16,179  
Operating Properties | Data Center Shells | Single-tenant data centers | Operating office properties      
Construction and Redevelopment Activities      
Gain on Disposition   $ 17,900  
Number of properties contributed | buillding   6  
Operating Properties | Regional Office | Arborcrest Corporate Campus      
Construction and Redevelopment Activities      
Number of Buildings | buillding   4  
Square footage of real estate properties (in square feet) | ft²   654  
Transaction Value   $ 142,800  
Gain on Disposition   $ 4,742  
Operating Properties | Regional Office | 8003 Corporate Drive      
Construction and Redevelopment Activities      
Number of Buildings | buillding   1  
Square footage of real estate properties (in square feet) | ft²   18  
Transaction Value   $ 2,400  
Gain on Disposition   $ 0  
Operating Properties | Regional Office | 8007, 8013, 8015, 8019 and 8023-8027 Corporate Drive      
Construction and Redevelopment Activities      
Number of Buildings | buillding   5  
Square footage of real estate properties (in square feet) | ft²   130  
Transaction Value   $ 14,513  
Gain on Disposition   $ 1,906  
Operating Properties | Fort Meade/BW Corridor | 1341 and 1343 Ashton Road      
Construction and Redevelopment Activities      
Number of Buildings | buillding   2  
Square footage of real estate properties (in square feet) | ft²   25  
Transaction Value   $ 2,900  
Gain on Disposition   $ 848  
Operating Properties | Fort Meade/BW Corridor | 1302, 1304 & 1306 Concourse Drive      
Construction and Redevelopment Activities      
Number of Buildings | buillding   3  
Square footage of real estate properties (in square feet) | ft²   299  
Transaction Value   $ 48,100  
Gain on Disposition   $ 8,683