Note 15 - Earnings Per Share - Antidilutive Securities Excluded From Computation of Earnings per Share (Details) - shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Employee Stock Option [Member]      
Antidilutive securities (in shares) 22,638 173,925 92,054
Antidilutive Securities, Convertible Preferred Stock [Member]      
Antidilutive securities (in shares) 803,442 700,241