Note 9 - Summary of Status of Company's Unvested Option Shares (Details) - Employee Stock Option [Member]	9 Months Ended
	Sep. 30, 2015 $ / shares shares
Unvested (in shares)	227,400
Unvested (in dollars per share) | $ / shares	$ 4.35
Options granted (in shares)	15,300
Options granted (in dollars per share) | $ / shares	$ 3.71
Options cancelled (in shares)	(6,300)
Options cancelled (in dollars per share) | $ / shares	$ 3.63
Options vested (in shares)	(48,750)
Options vested (in dollars per share) | $ / shares	$ 5.41
Unvested (in shares)	187,650
Unvested (in dollars per share) | $ / shares	$ 4.02