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
		Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Net income		$ 4,139	$ 4,920	$ 5,072	$ 4,329	$ 3,847	$ 916	$ 9,059	$ 4,763
Weighted average shares - basic (in shares)	[1]	16,736				16,660		16,721	17,178
Effect of potentially dilutive common shares (in shares)	[2]	87				29		82	39
Weighted average number of common shares outstanding - diluted (in shares)		16,823				16,689		16,803	17,217
Earnings per share - basic (in dollars per share)		$ 0.25				$ 0.23		$ 0.54	$ 0.28
Earnings per share - diluted (in dollars per share)		$ 0.25				$ 0.23		$ 0.54	$ 0.28
Anti-dilutive options not included in diluted earnings per share calculation (in shares)		0				76		0	60

[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.