Property (Schedule Of Property) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Real Estate [Abstract]
Land	$ 952,879	$ 929,958
Land held for development	90,064	95,524
Land under development	14,942	17,367
Buildings and improvements	3,318,140	3,152,215
Construction in-progress	70,510	67,895
Total	$ 4,446,535	$ 4,262,959