Income Taxes (Schedule Of Reconciliation Of Beginning And Ending Amount Of Unrecognized Tax Benefits ) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Beginning of year	$ 6,392	$ 4,678	$ 4,435
Additions based on tax positions related to the current year	918	1,695	1,677
Additions for tax positions in prior years	770	657	283
Reductions for tax positions in prior years	(2,907)	(38)	(163)
Reductions as a result of completed audit examinations	0	0	(1,554)
Reductions as a result of a lapse of the applicable statute of limitations	(309)	(600)	0
End of year	$ 4,864	$ 6,392	$ 4,678