Note 19 - Selected Quarterly Financial Data (Unaudited) - Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Interest income	$ 11,718	$ 11,693	$ 11,234	$ 10,440	$ 10,121	$ 9,605	$ 9,183	$ 8,939	$ 45,085	$ 37,848
Interest expense	2,581	2,438	1,997	1,562	1,321	1,280	1,143	1,056	8,578	4,800
Net interest income	9,137	9,255	9,237	8,878	8,800	8,325	8,040	7,883	36,507	33,048
Provision for loan and lease losses	(199)	1,149	880	720	283	543	421	(478)	2,550	769
Net interest income after provision (credit) for loan and lease losses	9,336	8,106	8,357	8,158	8,517	7,782	7,619	8,361	33,957	32,279
Non-interest income	7,422	1,320	1,529	1,519	1,918	1,714	2,023	1,570	11,790	7,225
Non-interest expense	7,941	7,188	6,966	7,232	7,804	6,397	6,940	6,928	29,327	28,069
Income before income taxes	8,817	2,238	2,920	2,445	2,631	3,099	2,702	3,003	16,420	11,435
Income tax expense	1,749	388	508	426	8,745	827	910	806	$ 3,071	$ 11,288
Net income	$ 7,068	$ 1,850	$ 2,412	$ 2,019	$ (6,114)	$ 2,272	$ 1,792	$ 2,197
Basic (in dollars per share)	$ 0.42	$ 0.11	$ 0.14	$ 0.12	$ (0.36)	$ 0.14	$ 0.11	$ 0.13	$ 0.79	$ 0.01
Diluted (in dollars per share)	$ 0.42	$ 0.11	$ 0.14	$ 0.12	$ (0.36)	$ 0.14	$ 0.11	$ 0.13	$ 0.79	$ 0.01