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							9 Months Ended
		Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Net income		$ 4,642	$ 3,644	$ 2,306	$ 4,839	$ 4,032	$ 3,618	$ 3,241	$ 10,592	$ 10,891
Weighted average shares - basic (in shares)	[1]	18,130				16,252			17,918	16,242
Effect of potentially dilutive common shares (in shares)	[2]	66				90			63	85
Weighted average number of common shares outstanding - diluted (in shares)		18,196				16,342			17,981	16,327
Earnings per share - basic (in dollars per share)		$ 0.26				$ 0.25			$ 0.59	$ 0.67
Earnings per share - diluted (in dollars per share)		$ 0.26				$ 0.25			$ 0.59	$ 0.67
Share-based Payment Arrangement, 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.