Note 2 - Common Stock Outstanding and Earnings Per Share - Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Net income		$ 3,618	$ 2,209	$ 6,859	$ 4,461	$ 7,344
Weighted average shares - basic (in shares)	[1]	16,245	15,014	16,237	14,220
Effect of potentially dilutive common shares (2) (in shares)	[2]	80	99	82	101
Weighted average number of common shares outstanding - diluted (in shares)		16,325	15,113	16,319	14,321
Earnings per share - basic (in dollars per share)		$ 0.22	$ 0.15	$ 0.42	$ 0.31
Earnings per share - diluted (in dollars per share)		$ 0.22	$ 0.15	$ 0.42	$ 0.31
Employee Stock Option [Member]
Anti-dilutive options not included in diluted earnings per share calculation (in shares)
Restricted Stock [Member]
Anti-dilutive options not included in diluted earnings per share calculation (in shares)

[1] Excludes unvested restricted shares because they do not have dividend or voting rights

[2] Represents the effects of the assumed exercise of stock options and vesting of non-participating restricted shares.