Segment Reporting (Schedule Of Reconciliation Of Net Operating Income To Income From Continuing Operations) (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Segment Reporting [Abstract]        
Net operating income [1] $ 40,907 $ 47,474 $ 78,240 $ 74,831
Depreciation and amortization (42,365) (44,711) (83,167) (89,696)
Realized gains (losses) on disposition of rental property, net 34,399 54,584 34,543 54,584
Gain on sale of investment in unconsolidated joint ventures 6,448   6,448  
Net income 39,389 57,347 36,064 39,719
Noncontrolling interest in consolidated joint ventures 373 290 863 612
Noncontrolling interest in Operating Partnership (4,383) (6,514) (4,069) (4,506)
Net income available to common shareholders $ 35,379 $ 51,123 $ 32,858 $ 35,825
[1] Net operating income represents total revenues less total operating and interest expenses (as defined in Note "a"), plus equity in earnings (loss) of unconsolidated joint ventures, for the period.