Real Estate And Accumulated Depreciation (Changes In Accumulated Depreciation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Balance at beginning of year	$ 1,108,188	$ 1,166,126	$ 1,184,546
Additions at cost	109,825	118,664	132,900
Retirements or sales	(107,338)	(176,602)	(127,391)
Property held for sale	0	0	(23,929)
Balance at end of year	$ 1,110,675	$ 1,108,188	$ 1,166,126