Note 4 - Stock-based Compensation - Summary of Stock Options (Details)	9 Months Ended
	Sep. 30, 2015 USD ($) $ / shares shares
Shares outstanding (in shares) | shares	274,500
Shares outstanding - weighted average exercise price (in dollars per share) | $ / shares	$ 1.76
Shares outstanding - weighted average remaining contractual life	5 years 292 days
Shares outstanding - aggregate intrinsic value	$ 329,280
Shares vested and exercisable (in shares) | shares	254,500
Shares vested and exercisable - weighted average exercise price (in dollars per share) | $ / shares	$ 1.72
Shares vested and exercisable - weighted average remaining contractual life	5 years 182 days
Shares vested and exercisable - aggregate intrinsic value	$ 316,880