Segment Information (Schedule Of Sales By Geographic Location) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Total revenue	$ 2,824	$ 2,837
United States [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenue	2,234	2,237
Canada [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenue	565	583
Other countries | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenue	$ 25	$ 17