Note 3 - Supplemental Balance Sheet Information (in Thousands) - Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets, Gross, Total	$ 5,652	$ 5,021
Less accumulated amortization	(3,357)	(2,766)
Intangible assets, net	2,295	2,255
Customer Contracts And Lists [Member]
Finite-Lived Intangible Assets, Gross, Total	3,362	2,731
Trade Names [Member]
Finite-Lived Intangible Assets, Gross, Total	900	900
Patents [Member]
Finite-Lived Intangible Assets, Gross, Total	870	870
Noncompete Agreements [Member]
Finite-Lived Intangible Assets, Gross, Total	$ 520	$ 520