XML 55 R41.htm IDEA: XBRL DOCUMENT v3.20.4
Real Estate - Additional Information (Detail)
1 Months Ended 12 Months Ended
Dec. 31, 2018
USD ($)
Sep. 30, 2018
USD ($)
May 31, 2018
USD ($)
a
shares
Aug. 31, 2016
shares
Dec. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Sep. 01, 2019
USD ($)
Dec. 31, 2017
USD ($)
Real Estate Properties [Line Items]                  
Acquisition costs     $ 200,000            
Development in process         $ 69,477,000 $ 335,644,000      
Total purchase price $ 1,948,165,000       2,124,796,000 2,081,597,000 $ 1,948,165,000   $ 1,803,200,000
Below market lease, carrying amount         23,700,000 24,100,000      
Below market lease, accumulated amortization         15,000,000.0 13,900,000      
Accretion income, intangible liabilities         1,400,000 1,500,000 1,700,000    
Above Market Rent                  
Real Estate Properties [Line Items]                  
Intangible assets gross carrying amount         600,000 600,000      
Intangible assets, accumulated amortization         128,900 108,300      
Amortization expense         $ 43,600 109,600 110,500    
Weighted-average amortization period         7 years        
Below Market Rent                  
Real Estate Properties [Line Items]                  
Weighted-average amortization period         5 years        
Lease acquisition costs                  
Real Estate Properties [Line Items]                  
Intangible assets gross carrying amount         $ 11,000,000.0 11,700,000      
Intangible assets, accumulated amortization         8,600,000 8,500,000      
Amortization expense         $ 600,000 900,000 1,300,000    
Weighted-average amortization period         4 years 3 months 18 days        
Ashbrook Marketplace                  
Real Estate Properties [Line Items]                  
Limited partnership units issued     $ 8,800,000       8,776,000    
Development in process         $ 153,000 19,128,000      
Hampden House (formerly 7316 Wisconsin Avenue)                  
Real Estate Properties [Line Items]                  
Acquisition costs   $ 700,000              
Payments to acquire real estate   $ 35,500,000              
Development in process         $ 50,723,000 $ 44,638,000   $ 42,600,000  
Parcel Adjacent to 7316 Wisconsin Avenue                  
Real Estate Properties [Line Items]                  
Payments to acquire real estate 4,500,000                
BF Saul Real Estate Investment Trust | Ashbrook Marketplace                  
Real Estate Properties [Line Items]                  
Limited partnership units issued (in shares) | shares     176,680 176,680          
Area of land | a     13.7            
2018 Acquisitions                  
Real Estate Properties [Line Items]                  
Total purchase price 49,450,000           49,450,000    
2018 Acquisitions | In-place Leases                  
Real Estate Properties [Line Items]                  
Intangible assets 886,000           886,000    
2018 Acquisitions | Above Market Rent                  
Real Estate Properties [Line Items]                  
Intangible assets 168,000           168,000    
2018 Acquisitions | Below Market Rent                  
Real Estate Properties [Line Items]                  
Intangible assets $ 21,000           $ 21,000