Revenue Concentrations, Significant Customers, and Geographic Areas (Summary Of Revenue By Product Line) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Concentration Risk [Line Items]
Revenues	$ 25,204	$ 15,996	$ 42,936	$ 32,425
High Precision 3D and 2D Sensors [Member]
Concentration Risk [Line Items]
Revenues	7,131	4,745	13,488	8,867
Inspection and Metrology Systems [Member]
Concentration Risk [Line Items]
Revenues	12,581	7,661	18,920	16,022
Semiconductor Sensors [Member]
Concentration Risk [Line Items]
Revenues	$ 5,492	$ 3,590	$ 10,528	$ 7,536