Note 14 - Employee Benefits - Option Activity (Details)	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Balance (in shares) | shares	918,583
Balance (in dollars per share) | $ / shares	$ 12.02
Granted (in shares) | shares	154,500
Granted (in dollars per share) | $ / shares	$ 21.26
Exercised (in shares) | shares	(105,588)
Exercised (in dollars per share) | $ / shares	$ 8.91
Forfeited (in shares) | shares	(28,302)
Forfeited (in dollars per share) | $ / shares	$ 15.66
Balance (in shares) | shares	939,193
Balance (in dollars per share) | $ / shares	$ 13.78
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number | shares	545,713
Exercisable at December 31, 2018 (in dollars per share) | $ / shares	$ 11.49