Note 8 - Stock-based Compensation - Allocation of Share-based Compensation Expense (Details) - Restricted Stock [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Cost of Sales [Member]
Allocated Share-based Compensation Expense	$ 2	$ 2	$ 5	$ 5
Selling and Marketing Expense [Member]
Allocated Share-based Compensation Expense	2	2	3	3
Research and Development Expense [Member]
Allocated Share-based Compensation Expense	3	3	5	5
General and Administrative Expense [Member]
Allocated Share-based Compensation Expense	132	24	165	48
Allocated Share-based Compensation Expense	$ 139	$ 31	$ 178	$ 61