Note 4 - Loans and Allowance for Loan Losses - Allowance for Loan Losses and the Recorded Investment In Loans by Impairment Method (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Individually evaluated for impairment	$ 3,182	$ 2,948
Collectively evaluated for impairment	6,601	6,396
Total ending allowance balance	9,783	9,344	$ 10,315	$ 13,968
Loans individually evaluated for impairment	23,141	41,895
Loans collectively evaluated for impairment	1,012,122	929,080
Loans, net of unearned income	1,035,263	970,975
Real Estate Portfolio Segment [Member]
Individually evaluated for impairment	2,694	2,566
Collectively evaluated for impairment	5,815	5,639
Total ending allowance balance	8,509	8,205	9,173	12,542
Loans individually evaluated for impairment	22,381	41,311
Loans collectively evaluated for impairment	894,425	829,581
Loans, net of unearned income	916,806	870,892
Commercial Portfolio Segment [Member]
Individually evaluated for impairment	270	236
Collectively evaluated for impairment	681	618
Total ending allowance balance	951	854	820	1,153
Loans individually evaluated for impairment	448	438
Loans collectively evaluated for impairment	110,094	90,410
Loans, net of unearned income	110,542	90,848
Consumer Portfolio Segment [Member]
Individually evaluated for impairment	218	146
Collectively evaluated for impairment	105	139
Total ending allowance balance	323	285	$ 322	$ 273
Loans individually evaluated for impairment	312	146
Loans collectively evaluated for impairment	7,603	9,089
Loans, net of unearned income	$ 7,915	$ 9,235