Note 3 - Supplemental Balance Sheet Information (in Thousands) - Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets, Gross, Total	$ 5,021	$ 4,970
Less accumulated amortization	(2,225)	(1,638)
Intangible assets, net	2,796	3,332
Customer Contracts And Lists [Member]
Finite-Lived Intangible Assets, Gross, Total	2,731	2,680
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