Note 8 - Stock-Based Compensation (Details) - Stock-Based Compensation Expense is Recognized for Stock Options Granted (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share based compensation	$ 185	$ 21	$ 234	$ 126
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share based compensation	47	14	68	98
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share based compensation	$ 138	$ 7	$ 166	$ 28