Note 9 - Share-based Compensation - Schedule of Share-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Stock-based compensation expense	$ 55	$ 129	$ 129	$ 266
Cost of Sales [Member]
Stock-based compensation expense	2	4	4	9
Selling and Marketing Expense [Member]
Stock-based compensation expense		10	1	20
Research and Development Expense [Member]
Stock-based compensation expense	11	27	23	57
General and Administrative Expense [Member]
Stock-based compensation expense	$ 42	$ 88	$ 101	$ 180