Quarterly report pursuant to Section 13 or 15(d)

Commitments And Contingencies (Construction Projects) (Narrative) (Details)

v3.20.1
Commitments And Contingencies (Construction Projects) (Narrative) (Details)
$ in Thousands
 3 Months Ended
Mar. 31, 2020
USD ($)
item
Mar. 31, 2019
USD ($)
Dec. 31, 2019
USD ($)
Commitments And Contingencies [Line Items]      
Properties aggregate net book value $ 898,000    
Costs of the project incurred 3,853 $ 6,112  
Amount outstanding 277,000   $ 329,000
Building 8/9 [Member]      
Commitments And Contingencies [Line Items]      
Costs of the project incurred $ 77,700    
Delivery date to tenant first quarter 2021    
Number of units | item 313    
Total project costs $ 142,900    
Amount to fund 50,900    
233 Canoe Brook [Member]      
Commitments And Contingencies [Line Items]      
Costs of the project incurred $ 55,900    
Delivery date to tenant fourth quarter 2020    
Number of units | item 198    
Total project costs $ 99,400    
Amount to fund 35,400    
25 Christopher Columbus [Member]      
Commitments And Contingencies [Line Items]      
Costs of the project incurred $ 195,400    
Delivery date to tenant first quarter 2022    
Number of units | item 750    
Amount outstanding $ 38,400    
Amount of project costs funded 138,500    
Total project costs 469,500    
Amount to fund 169,500    
Construction Loan [Member] | Building 8/9 [Member]      
Commitments And Contingencies [Line Items]      
Amount outstanding 92,000    
Construction Loan [Member] | 233 Canoe Brook [Member]      
Commitments And Contingencies [Line Items]      
Amount outstanding 64,000    
Construction Loan [Member] | 25 Christopher Columbus [Member]      
Commitments And Contingencies [Line Items]      
Amount outstanding $ 300,000