Note 5 - Revenue From Contracts With Customers - Disaggregation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net revenues	$ 19,556	$ 11,230
Semiconductor Market [Member]
Net revenues	13,320	5,011
Industrial Market [Member]
Net revenues	3,828	4,227
Defense/ Aerospace [Member]
Net revenues	1,129	1,408
Telecommunications Market [Member]
Net revenues	340	411
Other Multi Markets [Member]
Net revenues	939	173
Thermal Testing Products [Member]
Net revenues	4,305	4,147
Thermal Process [Member]
Net revenues	5,566	3,748
Semiconductor Production Test Products [Member]
Net revenues	8,320	1,825
Service and Other Products [Member]
Net revenues	1,365	1,510
End User [Member]
Net revenues	17,660	9,922
OEM and Integrators [Member]
Net revenues	$ 1,896	$ 1,308