Income Taxes (Schedule Of Significant Changes To Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Abstract]
Balance at January 1,	$ 1,323	$ 1,348	$ 1,123
Unrecognized tax benefits due to positions taken in current year	200	234	453
Decrease due to expiration of statute of limitations	(219)	(259)	(228)
Balance at December 31,	$ 1,304	$ 1,323	$ 1,348