Property (Schedule Of Property) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Real Estate [Abstract]
Land	$ 1,107,072	$ 929,958
Land held for development	82,953	95,524
Land under development	51,761	17,367
Buildings and improvements	3,489,685	3,152,215
Construction in-progress	57,674	67,895
Total	$ 4,789,145	$ 4,262,959