Other Comprehensive Income Loss (Schedule Of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	$ (1,102)	$ (1,406)
Other comprehensive loss	(204)	(490)
Balance	(1,306)	(1,896)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	(1,285)	(1,475)
Other comprehensive loss	(147)	(600)
Balance	(1,432)	(2,075)
Available-for-sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	183	69
Other comprehensive loss	(57)	110
Balance	$ 126	$ 179