Segment Information (Sales By Geographic Location) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Total revenue	$ 3,098	$ 3,489	$ 5,890	$ 6,313
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenue	3,098	3,489	5,890	6,313
United States [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenue	2,278	2,556	4,429	4,790
Canada [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenue	819	917	1,443	1,482
Other Countries [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenue	$ 1	$ 16	$ 18	$ 41