Note 3 - Revenue from Contracts with Customers - Summary of Net Revenues by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net revenues	$ 14,036	$ 56,414
Europe [Member]
Net revenues	4,366	7,472
Latin America [Member]
Net revenues	3,503	20,062
Asia Pacific [Member]
Net revenues	2,201	7,763
Africa [Member]
Net revenues	1,772	12,240
North America [Member]
Net revenues	1,208	3,888
Middle East [Member]
Net revenues	727	954
Other [Member]
Net revenues	$ 259	$ 4,035