Goodwill And Other Intangible Assets (Schedule Of Impairment Of Goodwill) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill And Other Intangible Assets [Abstract]
Goodwill, gross	$ 233,818	$ 230,679
Accumulated impairment losses	(58,467)	(58,467)
Goodwill, net	$ 175,351	$ 172,212	$ 172,956