Revenue Concentrations, Significant Customers, and Geographic Areas (Summary Of Revenue By Product Line) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Concentration Risk [Line Items]
Revenues	$ 27,762	$ 20,820	$ 70,698	$ 53,245
High Precision 3D and 2D Sensors
Concentration Risk [Line Items]
Revenues	5,453	3,645	18,941	12,512
Inspection and Metrology Systems
Concentration Risk [Line Items]
Revenues	14,914	13,339	33,834	29,361
Semiconductor Sensors
Concentration Risk [Line Items]
Revenues	$ 7,395	$ 3,836	$ 17,923	$ 11,372