Note 16 - Restructuring Activities - Charges and Net Assets (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
Revenues from external customers	$ 6,216	$ 8,155	$ 4,401	$ 3,778	$ 4,912	$ 6,452	$ 8,948	$ 10,155	$ 22,550	$ 30,467
Net loss	(1,543)	$ 2,376	$ (2,544)	$ (2,567)	(4,340)	$ (1,278)	$ (945)	$ (1,289)	(4,278)	(7,852)
Total assets	7,767				5,431				7,767	5,431
Total net assets	30,088				31,606				30,088	31,606
CHINA
Revenues from external customers									25	329
Net loss									(281)	(1,767)
Total assets	2,463				4,249				2,463	4,249
Total liabilities	396				399				396	399
Total net assets	$ 2,067				$ 3,850				$ 2,067	$ 3,850