Property (Schedule Of Property) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Real Estate [Abstract]
Land	$ 913,304	$ 821,614
Land held for development	100,099	103,349
Land under development	20,356	24,297
Buildings and improvements	3,171,840	3,061,616
Construction in-progress	71,535	65,218
Total	$ 4,277,134	$ 4,076,094