Note 11 - Stock Awards - Stock Option Activity (Details) - $ / shares	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Stock Options Granted, Average Exercise Price (in dollars per share)	$ 13.91	$ 8.30
Outstanding, beginning of period, Number of Shares (in shares)	272,550	175,550
Outstanding, beginning of period, Average Exercise Price (in dollars per share)	$ 8.21	$ 8.17
Stock Options Granted, Number of Shares (in shares)	68,600	97,000
Stock Options Exercised, Number of Shares (in shares)	19,316	0
Stock Options Exercised, Average Exercise Price (in dollars per share)	$ 8.15	$ 0
Stock Options Expired, Number of Shares (in shares)	0	0
Stock Options Expired, Average Exercise Price (in dollars per share)	$ 0	$ 0
Stock Options Forfeited, Number of Shares (in shares)	3,333	0
Stock Options Forfeited, Average Exercise Price (in dollars per share)	$ 11.79	$ 0
Options outstanding, end of period, Number of Shares (in shares)	318,501	272,550
Options outstanding, end of period, Average Exercise Price (in dollars per share)	$ 9.41	$ 8.21
Options exercisable, end of period, Number of Shares (in shares)	208,633	175,550
Options exercisable, end of period, Average Exercise Price (in dollars per share)	$ 8.20	$ 8.17