Quarterly report pursuant to Section 13 or 15(d)

Disclosure Of Fair Value Of Assets And Liabilities (Narrative) (Details)

v3.19.1
Disclosure Of Fair Value Of Assets And Liabilities (Narrative) (Details)
3 Months Ended
Mar. 31, 2019
USD ($)
property
Dec. 31, 2018
USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value of Company's long-term debt $ 2,595,592,000 $ 2,711,712,000
Principal balance outstanding 2,686,317,000 2,792,651,000
Aggregate carrying value 33,239,000 $ 108,848,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Paramus, New Jersey [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Aggregate carrying value $ 33,239,000  
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Office [Member] | Paramus, New Jersey [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Number of properties held for sale | property 1  
Aggregate carrying value $ 39,400,000  
Estimated expected sales proceeds 36,900,000  
Unrealized losses on rental properties held for sale 2,500,000  
Disposal Group, Not Discontinued Operations [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Unrealized losses on rental properties held for sale $ (2,500,000)