Note 6 - Revenue From Contracts With Customers (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue from Contract with Customer, Including Assessed Tax	$ 30,941	$ 30,771	$ 95,418	$ 84,423
Thermal Testing Products [Member]
Revenue from Contract with Customer, Including Assessed Tax	4,742	5,836	16,734	16,844
Video Imaging [Member]
Revenue from Contract with Customer, Including Assessed Tax	1,945	$ 2,447	7,027	$ 6,692
Revision of Prior Period, Error Correction, Adjustment [Member]
Revenue from Contract with Customer, Including Assessed Tax	$ (1,722)		(1,722)
Revision of Prior Period, Error Correction, Adjustment [Member] | Thermal Testing Products [Member]
Revenue from Contract with Customer, Including Assessed Tax			(1,291)
Revision of Prior Period, Error Correction, Adjustment [Member] | Video Imaging [Member]
Revenue from Contract with Customer, Including Assessed Tax			$ (431)