Quarterly report pursuant to Section 13 or 15(d)

Note 5 - Company's Stock Option Plans (Details)

v3.5.0.2
Note 5 - Company's Stock Option Plans (Details) - USD ($)
 6 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Options outstanding, shares (in shares) 218,200 239,023
Options outstanding, weighted average exercise price (in dollars per share) $ 7.65 $ 7.81
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures 50,000  
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price $ 3.97  
Options outstanding, shares (in shares) [1] 268,200 221,635
Options outstanding, weighted average exercise price (in dollars per share) [1] $ 6.96 $ 7.91
Options outstanding, weighted average remaining contractual term [1] 4 years 219 days 4 years 255 days
Options outstanding, aggregate intrinsic value [1],[2] $ 134,102 $ 18,869
Options exercisable, shares (in shares) [1] 181,533 166,635
Options exercisable, weighted average exercise price (in dollars per share) [1] $ 8.18 $ 8.88
Options exercisable, weighted average remaining contractual term [1] 4 years 146 days 4 years 219 days
Options exercisable, aggregate intrinsic value [1],[2] $ 74,802 $ 18,869
Options exercisable and expected to be vested, shares (in shares) 254,883 212,835
Options exercisable and expected to be vested, weighted average exercise price (in dollars per share) $ 7.10 $ 8.04
Options exercisable and expected to be vested, weighted average remaining contractual term 4 years 219 days 4 years 255 days
Options exercisable and expected to be vested, aggregate intrinsic value [2] $ 125,230 $ 18,869
Exercised, shares (in shares)   (2,388)
Exercised, weighted average exercise price (in dollars per share)   $ 2.79
Exercised, aggregate intrinsic value [2]   $ 3,248
Forfeited/expired, shares (in shares)   (15,000)
Forfeited/expired, weighted average exercise price (in dollars per share)   $ 7.10
[1] Options with exercise prices ranging from $2.79 to $14.75.
[2] The intrinsic value of a stock option is the amount by which the market value of the underlying stock exceeds the exercise price of the option.