Revenue Concentrations, Significant Customers, and Geographic Areas (Schedule Of Long-lived Assets Attributable To Each Geographic Area's Operations) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	$ 3,549	$ 3,560
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	2,526	2,814
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	13	6
Asia And Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	$ 1,010	$ 740