Note 12 - Segment Information - Identifiable Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Identifiable Assets	$ 59,059	$ 59,715
Corporate, Non-Segment [Member]
Identifiable Assets	760	775
Thermal Testing Products [Member]
Identifiable Assets	51,223	51,621
EMS [Member]
Identifiable Assets	$ 7,076	$ 7,319