Property (Schedule Of Property) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Real Estate [Abstract]
Land	$ 1,109,163	$ 1,107,072
Land held for development	72,009	82,953
Land under development	48,780	51,761
Buildings and improvements	3,411,373	3,489,685
Construction in-progress	82,575	57,674
Total	$ 4,723,900	$ 4,789,145