Note 8 - Loans and Allowance for Loan Losses - Risk Category of Non Consumer Loans by Class (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Loans, net of unearned income	$ 1,064,215	$ 1,035,263
Real Estate Portfolio Segment [Member]
Loans, net of unearned income	935,975	916,806
Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member]
Loans, net of unearned income	128,183	129,181
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member]
Loans, net of unearned income	350,778	355,304
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member]
Loans, net of unearned income	457,014	432,321
Commercial Portfolio Segment [Member]
Loans, net of unearned income	120,978	110,542
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans, net of unearned income	87,224	63,417
Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member]
Loans, net of unearned income	17,686	27,209
Commercial Portfolio Segment [Member] | Commercial Other [Member]
Loans, net of unearned income	16,068	19,916
Pass [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member]
Loans, net of unearned income	124,342	124,926
Pass [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member]
Loans, net of unearned income	326,533	330,401
Pass [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member]
Loans, net of unearned income	440,095	414,663
Pass [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans, net of unearned income	86,390	62,490
Pass [Member] | Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member]
Loans, net of unearned income	17,686	27,209
Pass [Member] | Commercial Portfolio Segment [Member] | Commercial Other [Member]
Loans, net of unearned income	16,051	19,898
Special Mention [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member]
Loans, net of unearned income	668	396
Special Mention [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member]
Loans, net of unearned income	8,975	9,196
Special Mention [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member]
Loans, net of unearned income	6,216	7,556
Special Mention [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans, net of unearned income	448	474
Special Mention [Member] | Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member]
Loans, net of unearned income	0	0
Special Mention [Member] | Commercial Portfolio Segment [Member] | Commercial Other [Member]
Loans, net of unearned income	14	18
Substandard [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member]
Loans, net of unearned income	3,173	3,859
Substandard [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member]
Loans, net of unearned income	15,270	15,707
Substandard [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member]
Loans, net of unearned income	10,703	10,102
Substandard [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans, net of unearned income	386	453
Substandard [Member] | Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member]
Loans, net of unearned income	0	0
Substandard [Member] | Commercial Portfolio Segment [Member] | Commercial Other [Member]
Loans, net of unearned income	3	0
Doubtful [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member]
Loans, net of unearned income	0	0
Doubtful [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member]
Loans, net of unearned income	0	0
Doubtful [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member]
Loans, net of unearned income	0	0
Doubtful [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans, net of unearned income	0	0
Doubtful [Member] | Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member]
Loans, net of unearned income	0	0
Doubtful [Member] | Commercial Portfolio Segment [Member] | Commercial Other [Member]
Loans, net of unearned income	$ 0	$ 0