Note 9 - Information About Geographic Areas and Operating Segments - Revenue and Long-lived Assets by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Total revenue	$ 8,924	$ 14,180	$ 25,653	$ 29,276
Total long-lived assets	1,823		1,823		$ 2,533
North America [Member]
Total revenue	7,754	12,039	21,530	24,906
Total long-lived assets	1,601		1,601		2,016
Asia [Member]
Total revenue	775	1,443	3,089	3,149
Total long-lived assets					177
Europe [Member]
Total revenue	395	$ 698	1,034	$ 1,221
Total long-lived assets	$ 222		$ 222		$ 340