Deferred Charges, Goodwill And Other Assets, Net (Schedule Of Deferred Charges, Goodwill And Other Assets) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Aug. 31, 2017
Deferred Charges, Goodwill And Other Assets [Line Items]        
Deferred leasing costs $ 173,822 $ 199,515    
Deferred financing costs - unsecured revolving credit facility 5,356 4,945    
Deferred charges, net 179,178 204,460    
Accumulated amortization (71,326) (98,956)    
Deferred charges, net 107,852 105,504    
Notes receivable 47,409 50,167    
In-place lease values, related intangibles and other assets, net 89,860 102,757    
Goodwill 2,945 2,945    
Prepaid expenses and other assets, net 107,168 80,947    
Total deferred charges, goodwill and other assets, net 355,234 342,320    
Acquired Above And Below Market Lease Intangibles [Member]        
Deferred Charges, Goodwill And Other Assets [Line Items]        
Lease revenue 5,300 7,900 $ 1,900  
Acquisition-related Costs [Member]        
Deferred Charges, Goodwill And Other Assets [Line Items]        
Net sales proceeds held by qualified intermediary $ 49,200 26,900    
Notes Receivable 5.85 Interest Rate [Member]        
Deferred Charges, Goodwill And Other Assets [Line Items]        
Notes receivable   45,700    
Mortgage loan, maturity date Jul. 01, 2019      
Interest rate 5.85%      
Notes receivable $ 45,200     $ 44,700
Loan extension period 3 months      
Interest-Free Notes Receivable [Member]        
Deferred Charges, Goodwill And Other Assets [Line Items]        
Mortgage loan, maturity date Apr. 01, 2023      
Notes receivable $ 2,200 2,500    
Disposal Group, Not Discontinued Operations [Member] | Buyer [Member] | Bergen Portfolio [Member]        
Deferred Charges, Goodwill And Other Assets [Line Items]        
Notes receivable   $ 65,000