Note 3 - Revenue - Revenues Disaggregated by Geography (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues from external customers	$ 8,155	$ 6,452	$ 16,334	$ 25,555
UNITED STATES
Revenues from external customers	6,473	5,727	12,880	22,104
Latin America [Member]
Revenues from external customers	195	282	400	474
Europe [Member]
Revenues from external customers	904	283	1,494	1,568
Asia [Member]
Revenues from external customers	583	160	1,560	1,409
Non-US [Member]
Revenues from external customers	$ 1,682	$ 725	$ 3,454	$ 3,451