Note 4 - Restructuring Activities - Charges and Net Assets (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Revenues	$ 5,218		$ 4,401		$ 10,251	$ 8,179
Net income (loss)	(778)	$ 398	(2,544)	$ (2,567)	(380)	(5,111)
Total assets	50,061				50,061		$ 30,088
Total liabilities	4,163				4,163		7,767
CHINA
Revenues	4		3		15	5
Net income (loss)	(63)		$ (85)		(38)	$ 42
Total assets	1,428				1,428		2,463
Total liabilities	292				292		396
Total net assets	$ 1,136				$ 1,136		$ 2,067