Quarterly report pursuant to Section 13 or 15(d)

Real Estate - Properties Sold and Held for Sale (Details)

v3.20.1
Real Estate - Properties Sold and Held for Sale (Details)
ft² in Thousands, $ in Thousands
12 Months Ended
Dec. 19, 2019
USD ($)
ft²
Aug. 27, 2019
USD ($)
ft²
Aug. 21, 2019
USD ($)
ft²
Jul. 23, 2019
USD ($)
ft²
property
Jun. 26, 2019
USD ($)
ft²
Dec. 31, 2019
USD ($)
ft²
Apr. 21, 2020
USD ($)
ft²
Quantico Corporate Center | Office              
Properties Sold and Held for Sale [Line Items]              
Rentable Square Feet (sq ft) | ft²         272    
Contract Sales Price         $ 33,000    
(Loss) gain on sale         $ 1,000    
Shopping Center Portfolio              
Properties Sold and Held for Sale [Line Items]              
(Loss) gain on sale       $ 333,000      
Frederick Crossing and Frederick County Square              
Properties Sold and Held for Sale [Line Items]              
(Loss) gain on sale     $ 9,500        
Centre at Hagerstown              
Properties Sold and Held for Sale [Line Items]              
(Loss) gain on sale   $ (3,500)          
2019 Properties              
Properties Sold and Held for Sale [Line Items]              
Rentable Square Feet (sq ft) | ft²           2,184  
Contract Sales Price           $ 728,750  
(Loss) gain on sale           $ 398,985  
2019 Properties | Disposal group, not discontinued operations | Quantico Corporate Center | Office              
Properties Sold and Held for Sale [Line Items]              
Rentable Square Feet (sq ft) | ft²         272    
Contract Sales Price         $ 33,000    
(Loss) gain on sale         $ (1,046)    
2019 Properties | Disposal group, not discontinued operations | 1776 G Street | Office              
Properties Sold and Held for Sale [Line Items]              
Rentable Square Feet (sq ft) | ft² 262            
Contract Sales Price $ 129,500            
(Loss) gain on sale $ 61,007            
2019 Properties | Discontinued operations | Shopping Center Portfolio | Retail              
Properties Sold and Held for Sale [Line Items]              
Rentable Square Feet (sq ft) | ft²       800      
Contract Sales Price       $ 485,250      
(Loss) gain on sale       $ 333,023      
Number of properties | property       5      
2019 Properties | Discontinued operations | Frederick Crossing and Frederick County Square | Retail              
Properties Sold and Held for Sale [Line Items]              
Rentable Square Feet (sq ft) | ft²     520        
Contract Sales Price     $ 57,500        
(Loss) gain on sale     $ 9,507        
2019 Properties | Discontinued operations | Centre at Hagerstown | Retail              
Properties Sold and Held for Sale [Line Items]              
Rentable Square Feet (sq ft) | ft²   330          
Contract Sales Price   $ 23,500          
(Loss) gain on sale   $ (3,506)          
Subsequent Event | 2020 Properties              
Properties Sold and Held for Sale [Line Items]              
Rentable Square Feet (sq ft) | ft²             223
Contract Sales Price             $ 57,000
Subsequent Event | 2020 Properties | Disposal group, not discontinued operations | John Marshall II | Office              
Properties Sold and Held for Sale [Line Items]              
Rentable Square Feet (sq ft) | ft²             223
Contract Sales Price             $ 57,000