Note 3 - Net Earnings Per Common Share (Details Textual) - shares
3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount 100,459 102,297 101,680 102,297