Note 4 - Loans and Allowance for Loan Losses - Risk Category of Consumer Loans by Class (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Loans, net of unearned income	$ 1,035,263	$ 970,975
Consumer Portfolio Segment [Member]
Loans, net of unearned income	7,915	9,235
Consumer Portfolio Segment [Member] | Consumer Secured [Member]
Loans, net of unearned income	4,853	4,554
Consumer Portfolio Segment [Member] | Consumer Unsecured [Member]
Loans, net of unearned income	3,062	4,681
Performing Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Consumer Secured [Member]
Loans, net of unearned income	4,853	4,550
Performing Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Consumer Unsecured [Member]
Loans, net of unearned income	2,766	4,538
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Consumer Secured [Member]
Loans, net of unearned income	0	4
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Consumer Unsecured [Member]
Loans, net of unearned income	$ 296	$ 143