Deferred Charges, Goodwill And Other Assets, Net (Schedule Of Deferred Charges, Goodwill And Other Assets) (Details) - USD ($)
$ in Thousands
 1 Months Ended 3 Months Ended
Apr. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Aug. 11, 2017
Deferred Charges, Goodwill And Other Assets [Line Items]        
Deferred leasing costs   $ 149,948 $ 199,515  
Deferred financing costs - unsecured revolving credit facility [1]   4,945 4,945  
Deferred charges, gross   154,893 204,460  
Accumulated amortization   (60,815) (98,956)  
Deferred charges, net   94,078 105,504  
Notes receivable [2]   54,291 50,167  
In-place lease values, related intangibles and other assets, net   97,787 102,757  
Goodwill [3]   2,945 2,945  
Prepaid expenses and other assets, net [4]   57,456 80,947  
Total deferred charges, goodwill and other assets, net   306,557 $ 342,320  
Net sales proceeds held by qualified intermediary   $ 26,900    
Notes Receivable 5.85 Interest Rate [Member]        
Deferred Charges, Goodwill And Other Assets [Line Items]        
Interest rate   5.85%    
Notes receivable   $ 43,400   $ 44,700
Loan extension period   3 days    
Mortgage loan, maturity date   Jul. 01, 2019    
Prepayment of note receivable   $ 3,000    
Interest-Free Notes Receivable [Member]        
Deferred Charges, Goodwill And Other Assets [Line Items]        
Notes receivable   $ 2,500    
Mortgage loan, maturity date   Apr. 01, 2023    
Disposal Group, Not Discontinued Operations [Member] | Buyer [Member] | Notes Receivable 3.0 Interest Rate [Member]        
Deferred Charges, Goodwill And Other Assets [Line Items]        
Interest rate   3.00%    
Notes receivable   $ 4,000    
Mortgage loan, maturity date   Apr. 01, 2028    
Disposal Group, Not Discontinued Operations [Member] | Buyer [Member] | Notes Receivable 6.0 Interest Rate [Member]        
Deferred Charges, Goodwill And Other Assets [Line Items]        
Interest rate   6.00%    
Notes receivable   $ 2,800    
Mortgage loan, maturity date   May 01, 2018    
Disposal Group, Not Discontinued Operations [Member] | Buyer [Member] | Subsequent Event [Member] | Notes Receivable 6.0 Interest Rate [Member]        
Deferred Charges, Goodwill And Other Assets [Line Items]        
Prepayment of note receivable $ 600      
[1] Deferred financing costs related to all other debt liabilities (other than for the unsecured revolving credit facility) are netted against those debt liabilities for all periods presented. See Note 2: Significant Accounting Policies - Deferred Financing Costs.
[2] Includes as of March 31, 2018: a mortgage receivable with a balance of $43.4 million (acquired in August 2017) which bears interest at 5.85 percent and matures in July 2019 with a three-month extension option; a note receivable for $4.0 million (provided to an affiliate of the buyers in connection with a property sale in March 2018) which bears interest at 3.0 percent and matures in April 2028; a note receivable for $2.8 million (provided to an affiliate of the buyers in connection with a property sale in March 2018) which bears interest at 6.0 percent and matures in May 2018, of which a part prepayment of $0.6 million was received in April 2018; and an interest-free note receivable with a net present value of $2.5 million which matures in April 2023. The Company believes these balances are fully collectible.
[3] All goodwill is attributable to the Company's Multi-family Real Estate and Services segment.
[4] The balance as of March 31, 2018 reflects the receipt by the Company of $26.9 million of proceeds from 2017 property sales held by a qualified intermediary as of December 31, 2017.