Note 4 - Loans and Allowance for Loan Losses - Allowance for Loan Losses Activity by Portfolio Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Balance	$ 7,401	$ 7,639	$ 6,728	$ 7,499
Provision for loan losses	444	962	2,015	1,695
Loans charged off	(2,052)	(1,042)	(4,575)	(2,380)
Recoveries	360	756	1,985	1,501
Balance	6,153	8,315	6,153	8,315
Allowance for loan losses:
Balance	7,401	7,639	6,728	7,499
Provision for loan losses	444	962	2,015	1,695
Loans charged off	(2,052)	(1,042)	(4,575)	(2,380)
Recoveries	360	756	1,985	1,501
Balance	6,153	8,315	6,153	8,315
Residential Portfolio Segment [Member]
Balance	1,973	1,886	1,583	1,470
Provision for loan losses	(165)	681	96	1,261
Loans charged off	(465)	(184)	(872)	(421)
Recoveries	80	49	616	122
Balance	1,423	2,432	1,423	2,432
Allowance for loan losses:
Balance	1,973	1,886	1,583	1,470
Provision for loan losses	(165)	681	96	1,261
Loans charged off	(465)	(184)	(872)	(421)
Recoveries	80	49	616	122
Balance	1,423	2,432	1,423	2,432
Commercial Real Estate Portfolio Segment [Member]
Balance	2,222	2,392	2,186	2,978
Provision for loan losses	(536)	(378)	(403)	(1,041)
Loans charged off			(579)	(1)
Recoveries	92	431	574	509
Balance	1,778	2,445	1,778	2,445
Allowance for loan losses:
Balance	2,222	2,392	2,186	2,978
Provision for loan losses	(536)	(378)	(403)	(1,041)
Loans charged off			(579)	(1)
Recoveries	92	431	574	509
Balance	1,778	2,445	1,778	2,445
Commercial and Industrial Portfolio Segment [Member]
Balance	1,095	1,242	1,063	1,024
Provision for loan losses	1,193	197	1,497	196
Loans charged off	(1,168)	(136)	(1,512)	(140)
Recoveries	11	80	83	303
Balance	1,131	1,383	1,131	1,383
Allowance for loan losses:
Balance	1,095	1,242	1,063	1,024
Provision for loan losses	1,193	197	1,497	196
Loans charged off	(1,168)	(136)	(1,512)	(140)
Recoveries	11	80	83	303
Balance	1,131	1,383	1,131	1,383
Consumer Portfolio Segment [Member]
Balance	2,111	2,119	1,896	2,027
Provision for loan losses	(48)	462	825	1,279
Loans charged off	(419)	(722)	(1,612)	(1,818)
Recoveries	177	196	712	567
Balance	1,821	2,055	1,821	2,055
Allowance for loan losses:
Balance	2,111	2,119	1,896	2,027
Provision for loan losses	(48)	462	825	1,279
Loans charged off	(419)	(722)	(1,612)	(1,818)
Recoveries	177	196	712	567
Balance	$ 1,821	$ 2,055	$ 1,821	$ 2,055