Note 11 - Fair Value Measurements - Black -Scholes Model and Assumptions (Details)	9 Months Ended
	Sep. 30, 2017 $ / shares
Stock price (in dollars per share)	$ 1.66
Exercise price (in dollars per share)	$ 2.22
Expected term (Year)	4 years 182 days
Risk-free interest rate	1.80%
Expected volatility	109.30%
Dividend yield (in dollars per share)