Note 7 - Stock-based Compensation Expense by Department (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Cost of Sales [Member]
Allocated Share Based Compensation Expense	$ 114	$ 139	$ 217	$ 271
Selling and Marketing Expense [Member]
Allocated Share Based Compensation Expense	231	148	416	219
Research and Development Expense [Member]
Allocated Share Based Compensation Expense	180	115	362	239
General and Administrative Expense [Member]
Allocated Share Based Compensation Expense	457	291	948	589
Allocated Share Based Compensation Expense	$ 982	$ 693	$ 1,943	$ 1,318