Deferred Charges, Goodwill And Other Assets (Schedule Of Deferred Charges, Goodwill And Other Assets) (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended
Mar. 31, 2014
Dec. 31, 2013
Mar. 31, 2014
Mortgage Receivable [Member]
Mar. 31, 2014
Notes Receivable [Member]
Mar. 31, 2014
Interest-Free Notes Receivable [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]          
Deferred leasing costs $ 239,665 $ 258,648      
Deferred financing costs 21,718 25,366      
Deferred charges, gross 261,383 284,014      
Accumulated amortization (111,750) (131,669)      
Deferred charges, net 149,633 152,345      
Notes receivable 21,925 [1] 21,986 [1] 10,400 8,000 3,500
In-place lease values, related intangible and other assets, net 11,159 13,659      
Goodwill 2,945 2,945      
Prepaid expenses and other assets, net 43,068 27,584      
Total deferred charges, goodwill and other assets $ 228,730 $ 218,519      
Spread over LIBOR     6.00%    
Interest rate       8.00%  
[1] Includes a mortgage receivable for $10.4 million and bearing interest at LIBOR plus six percent; includes a note receivable for $8 million bearing interest at eight percent; and includes an interest-free note receivable with a net present value of $3.5 million as of March 31, 2014.