Property (Schedule Of Property) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Real Estate [Abstract]
Land	$ 928,510	$ 911,521
Land held for development	39,912	40,667
Land under development	21,241	53,076
Buildings and improvements	3,010,980	2,898,867
Construction in-progress	199,840	241,118
Total	$ 4,200,483	$ 4,145,249