Property (Schedule Of Property) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Real Estate [Abstract]
Land	$ 1,044,622	$ 929,958
Land held for development	85,563	95,524
Land under development	13,776	17,367
Buildings and improvements	3,505,911	3,152,215
Construction in-progress	75,843	67,895
Total	$ 4,725,715	$ 4,262,959