Real Estate And Accumulated Depreciation (Changes In Accumulated Depreciation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Balance at beginning of year	$ 1,166,126	$ 1,184,546	$ 1,087,642
Additions at cost	118,664	132,900	131,120
Retirements or sales	(176,602)	(127,391)	(33,132)
Property held for sale	0	(23,929)	(1,084)
Balance at end of year	$ 1,108,188	$ 1,166,126	$ 1,184,546