Geographic Information (Geographical Distribution Of Net Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	$ 23,602	$ 29,336	$ 45,105	$ 58,906
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	17,228	24,361	35,016	48,576
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	957	1,568	2,144	3,232
Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	2,791	3,219	4,991	6,728
All Other Countries [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	$ 2,625	$ 188	$ 2,953	$ 370