Note 3 - Revenue - Revenues Disaggregated by Geography (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues	$ 5,218	$ 4,401	$ 10,251	$ 8,179
UNITED STATES
Revenues	4,588	3,310	9,051	6,407
Latin America [Member]
Revenues	142	59	217	205
Europe [Member]
Revenues	301	197	676	590
Asia [Member]
Revenues	187	835	307	977
Non-US [Member]
Revenues	$ 630	$ 1,091	$ 1,200	$ 1,772