Note 12 - Segment Reporting - Income From Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income from operations	$ 6,927	$ 17,669	$ 27,292	$ 48,845
Operating Segments [Member]
Income from operations	6,927	17,669	27,292	48,845
Operating Segments [Member] | United States Segment [Member]
Income from operations	23,475	25,164	72,258	74,602
Operating Segments [Member] | Europe Segment [Member]
Income from operations	(2,223)	3,764	1,469	10,389
Operating Segments [Member] | Japan Segment [Member]
Income from operations	$ (14,325)	$ (11,259)	$ (46,435)	$ (36,146)