Note 4 - Restructuring Activities - Charges and Net Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Revenues from external customers	$ 5,033	$ 3,778
Net income	398	(2,567)
Total assets	51,043		$ 30,088
Total liabilities	4,520		7,767
CHINA
Revenues from external customers	11	2
Net income	25	$ 127
Total assets	2,242		2,463
Total liabilities	288		396
Total net assets	$ 1,954		$ 2,067