Note 4 - Segment Information - Long-Lived Tangible Assets by Geographical Area (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Long-lived tangible assets	$ 80,552	$ 113,777
Operating Segments [Member]
Long-lived tangible assets	1,570	2,390
Operating Segments [Member] | UNITED STATES
Long-lived tangible assets	1,535	2,324
Operating Segments [Member] | Europe [Member]
Long-lived tangible assets	$ 35	$ 66