Note 8 - Summary of Stock Options (Details) - Stock-based Compensation Expense Included in the Statement of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share based compensation expense	$ 48	$ 17	$ 90	$ 30
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share based compensation expense	4		8
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share based compensation expense	$ 44	$ 17	$ 82	$ 30