Note 15 - Information About Operating Segments and Geographic Areas - Revenue and Long-lived Assets by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Total revenue	$ 11,071	$ 10,420	$ 8,924	$ 16,729	$ 15,366	$ 14,641	$ 14,180	$ 15,096	$ 47,144	$ 59,283
Total long-lived assets	1,358				2,533				1,358	2,533
North America [Member]
Total revenue									40,339	50,110
Total long-lived assets	1,179				2,016				1,179	2,016
Asia [Member]
Total revenue									4,750	7,150
Total long-lived assets	178				177				178	177
Europe [Member]
Total revenue									2,055	2,023
Total long-lived assets					$ 340					$ 340