Annual report pursuant to Section 13 and 15(d)

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

v3.20.4
Commitments And Contingencies (Construction Projects) (Narrative) (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
USD ($)
item
Dec. 31, 2019
USD ($)
item
Dec. 31, 2018
USD ($)
Commitments And Contingencies [Line Items]      
Costs of the project incurred $ 13,717 $ 17,881 $ 23,799
Number of units | item 326 208  
Amount outstanding $ 25,000 $ 329,000  
Port Imperial South 9 [Member]      
Commitments And Contingencies [Line Items]      
Delivery date to tenant 2021    
Number of units | item 313    
Amount outstanding $ 46,300    
Amount of project costs funded 51,800    
Total project costs 143,800    
The Upton At Short Hills [Member]      
Commitments And Contingencies [Line Items]      
Costs of the project incurred $ 77,900    
Delivery date to tenant first quarter 2021    
Number of units | item 198    
Amount outstanding $ 42,500    
Amount of project costs funded 35,400    
Total project costs 99,400    
25 Christopher Columbus [Member]      
Commitments And Contingencies [Line Items]      
Costs of the project incurred $ 331,000    
Delivery date to tenant first quarter 2022    
Number of units | item 750    
Amount outstanding $ 161,500    
Total project costs 469,500    
Amount to fund 169,500    
Construction Loan [Member] | Port Imperial South 9 [Member]      
Commitments And Contingencies [Line Items]      
Development costs 98,100    
Amount outstanding 92,000    
Construction Loan [Member] | The Upton At Short Hills [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