Note 9 - Information Regarding Company's Stock Option Plans (Details) - Employee Stock Option [Member] - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Options outstanding (in shares)	722,675
Options outstanding, Weighted Average Exercise Price (in dollars per share)	$ 14.35
Options outstanding, Weighted Average Remaining Contractual Term	4 years 7 days	4 years 208 days
Options outstanding, Aggregate Intrinsic Value	$ 2,555
Granted, Shares (in shares)	15,300
Granted, Weighted Average Exercise Price (in dollars per share)	$ 13.26
Exercised, Shares (in shares)	(44,115)
Exercised, Weighted Average Exercise Price (in dollars per share)	$ 12.58
Cancelled or expired, Shares (in shares)	(7,275)
Cancelled or expired, Weighted Average Exercise Price (in dollars per share)	$ 16.34
Options outstanding (in shares)	686,585	722,675
Options outstanding, Weighted Average Exercise Price (in dollars per share)	$ 14.42	$ 14.35
Options outstanding, Aggregate Intrinsic Value	$ 566	$ 2,555
Options exercisable, Shares (in shares)	498,935
Options exercisable, Weighted Average Exercise Price (in dollars per share)	$ 13.74
Options exercisable, Weighted Average Remaining Contractual Term	3 years 116 days
Options exercisable, Aggregate Intrinsic Value	$ 562