Note 4 - Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Goodwill	$ 21,728	$ 21,605	$ 21,448
Finite-lived, Gross Carrying Amount	20,801	20,660
Finite-lived, Accumulated Amortization	12,603	10,470
Net Carrying Amount, finite-lived	8,198	10,190	13,206
Indefinite-lived, Gross Carrying Amount	8,398	8,369	8,428
Net Carrying Amount, indefinite-lived	8,398	8,369	$ 8,428
Intangible Assets, Gross Carrying Amount	29,199	29,029
Net Carrying Amount	16,596	18,559
Trademarks [Member]
Indefinite-lived, Gross Carrying Amount	8,398	8,369
Net Carrying Amount, indefinite-lived	8,398	8,369
Customer Relationships [Member]
Finite-lived, Gross Carrying Amount	16,407	16,313
Finite-lived, Accumulated Amortization	9,687	7,990
Net Carrying Amount, finite-lived	6,720	8,323
Patented Technology [Member]
Finite-lived, Gross Carrying Amount	2,895	2,855
Finite-lived, Accumulated Amortization	1,417	988
Net Carrying Amount, finite-lived	1,478	1,867
Patents [Member]
Finite-lived, Gross Carrying Amount	590	590
Finite-lived, Accumulated Amortization	590	590
Net Carrying Amount, finite-lived		0
Customer Backlog [Member]
Finite-lived, Gross Carrying Amount	499	492
Finite-lived, Accumulated Amortization	499	492
Net Carrying Amount, finite-lived		0
Computer Software, Intangible Asset [Member]
Finite-lived, Gross Carrying Amount	270	270
Finite-lived, Accumulated Amortization	270	270
Net Carrying Amount, finite-lived		0
Trade Names [Member]
Finite-lived, Gross Carrying Amount	140	140
Finite-lived, Accumulated Amortization	140	140
Net Carrying Amount, finite-lived		0
Electronic Test [Member]
Goodwill	3,436	3,369
Environmental Technologies [Member]
Goodwill	1,817	1,817
Process Technologies [Member]
Goodwill	$ 16,475	$ 16,419