Investments In Unconsolidated Joint Ventures (Summary Of Financial Position Of Unconsolidated Joint Ventures) (Details) - USD ($)
$ in Thousands
Sep. 30, 2016
Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]    
Rental property, net $ 1,725,663 $ 1,781,621
Other assets 268,233 307,000
Total assets 1,993,896 2,088,621
Mortgages and loans payable 1,335,918 1,298,293
Other liabilities 231,071 215,951
Partners'/members' capital 426,907 574,377
Total liabilities and partners'/members' capital 1,993,896 2,088,621
Company's net investment in unconsolidated joint ventures 319,807 303,457
South Pier At Harborside [Member]    
Schedule of Equity Method Investments [Line Items]    
Rental property, net 41,161 44,925
Other assets 17,959 15,249
Total assets 59,120 60,174
Mortgages and loans payable 100,000 63,741
Other liabilities 4,985 5,481
Partners'/members' capital (45,865) (9,048)
Total liabilities and partners'/members' capital 59,120 60,174
Other [Member]    
Schedule of Equity Method Investments [Line Items]    
Rental property, net 1,684,502 1,736,696
Other assets 250,274 291,751
Total assets 1,934,776 2,028,447
Mortgages and loans payable 1,235,918 1,234,552
Other liabilities 226,086 210,470
Partners'/members' capital 472,772 583,425
Total liabilities and partners'/members' capital 1,934,776 2,028,447
Company's net investment in unconsolidated joint ventures $ 319,807 $ 303,457