Quarterly report pursuant to Section 13 or 15(d)

Recent Transactions (Real Estate Held For Sale/Discontinued Operations/Dispositions) (Narrative) (Details)

v3.21.2
Recent Transactions (Real Estate Held For Sale/Discontinued Operations/Dispositions) (Narrative) (Details)
$ in Thousands
 1 Months Ended 3 Months Ended 9 Months Ended 33 Months Ended
May 24, 2021
USD ($)
Oct. 31, 2021
USD ($)
ft²
Sep. 30, 2021
USD ($)
ft²
property
Sep. 30, 2020
USD ($)
Sep. 30, 2021
USD ($)
ft²
property
Sep. 30, 2020
USD ($)
Sep. 30, 2021
USD ($)
ft²
property
Dec. 31, 2020
USD ($)
Dec. 19, 2019
ft²
Real Estate Properties [Line Items]                  
Unrealized gains (losses) on real estate held for sale         $ (3,485)        
Land and other impairments, net     $ 3,401 $ 1,292 11,333 $ 23,401      
Proceeds from the sale of property         42,702 $ 16,455      
Book value     $ 4,198,975   $ 4,198,975   $ 4,198,975 $ 4,638,643  
Suburban Office Portfolio [Member]                  
Real Estate Properties [Line Items]                  
Area of property (in square feet) | ft²                 6,600,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Office [Member]                  
Real Estate Properties [Line Items]                  
Number of properties held for sale | property     3   3   3    
Number of disposal groups | property         3        
Disposal Group, Not Discontinued Operations [Member]                  
Real Estate Properties [Line Items]                  
Unrealized gains (losses) on real estate held for sale         $ 439        
Area Of Real Estate Property Sold | ft²     2,800,833   2,800,833   2,800,833    
Gain (loss) on sale of property         $ 25,030        
Disposal Group, Not Discontinued Operations [Member] | Suburban Office Portfolio [Member]                  
Real Estate Properties [Line Items]                  
Area of property (in square feet) | ft²     6,000,000   6,000,000   6,000,000    
Gain (loss) on sale of property     $ 500   $ 500   $ 1,000    
Disposal Group, Not Discontinued Operations [Member] | Subsequent Event [Member] | Suburban Office Portfolio [Member]                  
Real Estate Properties [Line Items]                  
Area of property (in square feet) | ft²   248,480              
Proceeds from the sale of property   $ 25,300              
Disposal Group, Not Discontinued Operations [Member] | Properties Disposed One [Member] | Suburban Office Portfolio [Member]                  
Real Estate Properties [Line Items]                  
Number of properties sold | property             35    
Disposal Group, Not Discontinued Operations [Member] | Office [Member]                  
Real Estate Properties [Line Items]                  
Proceeds from the sale of property     $ 25,300   $ 25,300        
Disposal Group, Not Discontinued Operations [Member] | Office [Member] | Subsequent Event [Member]                  
Real Estate Properties [Line Items]                  
Area of property (in square feet) | ft²   248,480              
Parsippany, Madison, Short Hills, Edison, And Red Bank, New Jersey [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]                  
Real Estate Properties [Line Items]                  
Number of properties held for sale | property     2   2   2    
Hamilton, New Jersey [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]                  
Real Estate Properties [Line Items]                  
Gain (loss) on sale of property $ 111                
Proceeds from the sale of property $ 745                
Jersey City And Hoboken [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Office [Member]                  
Real Estate Properties [Line Items]                  
Number of real estate properties | property     2   2   2    
Area of property (in square feet) | ft²     1,800,000   1,800,000   1,800,000    
Estimated expected sales proceeds         $ 570,000        
Repayment of debt         400,000        
Jersey City And Hoboken [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Office [Member] | Minimum [Member]                  
Real Estate Properties [Line Items]                  
Estimated Prepayment Costs         20,000        
Jersey City And Hoboken [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Office [Member] | Maximum [Member]                  
Real Estate Properties [Line Items]                  
Estimated Prepayment Costs         $ 25,000        
Jersey City, New Jersey [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]                  
Real Estate Properties [Line Items]                  
Number of properties held for sale | property     2   2   2    
Unrealized gains (losses) on real estate held for sale     $ 3,000   $ 3,500        
Land and other impairments, net     300   700        
Jersey City, New Jersey [Member] | Discontinued Operations [Member]                  
Real Estate Properties [Line Items]                  
Unrealized gains (losses) on real estate held for sale     $ 3,700   $ 3,700