Note 21 - Quarterly Financial Data - Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended											12 Months Ended
	Dec. 31, 2017		Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income	$ 15,094		$ 14,983	$ 14,830	$ 14,379	$ 14,449	$ 14,619	$ 14,973		$ 15,330		$ 59,286	$ 59,371	$ 61,236
Interest expense	820		893	881	916	928	1,809	1,975		2,043		3,510	6,755	8,641
Net interest income	14,274		14,090	13,949	13,463	13,521	12,810	12,998		13,287		55,776	52,616	52,595
Provision for loan losses	87		(379)	(499)	580	175	(190)	(156)		(473)		(211)	(644)	(3,429)
Net interest income after provision for loan losses	14,187		14,469	14,448	12,883	13,346	13,000	13,154		13,760		55,987	53,260	56,024
Noninterest income	5,185		5,627	5,102	5,251	5,351	10,772	5,521	[1]	9,542	[2]	21,165	31,186	22,211
Noninterest expense	13,240		12,708	13,346	13,529	15,221	17,888	13,884	[1]	14,407		52,823	61,400	57,950
Income before income taxes	6,132		7,388	6,204	4,605	3,476	5,884	4,791		8,895
Income tax expense	7,567	[3]	2,076	1,722	1,276	931	1,560	1,235		2,715		12,641	6,441	5,293
Net income	$ (1,435)		$ 5,312	$ 4,482	$ 3,329	$ 2,545	$ 4,324	$ 3,556		$ 6,180		$ 11,688	$ 16,605	$ 14,992
Net income per common share, basic and diluted (in dollars per share)	$ (0.19)		$ 0.71	$ 0.60	$ 0.44	$ 0.34	$ 0.58	$ 0.47		$ 0.82		$ 1.56	$ 2.21	$ 1.95
Average common shares issued and outstanding, basic and diluted (in shares)	7,516		7,514	7,512	7,510	7,508	7,505	7,502		7,500		7,513	7,504	7,494

[1] Noninterest income includes $3.8 million of gain on the sale of investment securities and noninterest expense includes $3.8 million of loss on the early extinguishment of debt, both related to a series of transactions to deleverage the balance sheet.

[2] Noninterest income includes $4.1 million related to the gain on the early extinguishment of subordinated notes payable.

[3] Income tax expense includes $5.9 million related to the remeasurement of the Company's net deferred tax assets due to the change in Federal tax rates.