Note 8 - Loans and Allowance for Loan Losses - Risk Category of Non Consumer Loans by Class (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Loans, net of unearned income	$ 1,035,469	$ 1,035,263
Real Estate Portfolio Segment [Member]
Loans, net of unearned income	923,894	916,806
Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member]
Loans, net of unearned income	131,376	129,181
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member]
Loans, net of unearned income	351,838	355,304
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member]
Loans, net of unearned income	440,680	432,321
Commercial Portfolio Segment [Member]
Loans, net of unearned income	104,018	110,542
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans, net of unearned income	68,472	63,417
Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member]
Loans, net of unearned income	18,883	27,209
Commercial Portfolio Segment [Member] | Commercial Other [Member]
Loans, net of unearned income	16,663	19,916
Pass [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member]
Loans, net of unearned income	127,443	124,926
Pass [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member]
Loans, net of unearned income	326,807	330,401
Pass [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member]
Loans, net of unearned income	423,824	414,663
Pass [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans, net of unearned income	67,586	62,490
Pass [Member] | Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member]
Loans, net of unearned income	18,883	27,209
Pass [Member] | Commercial Portfolio Segment [Member] | Commercial Other [Member]
Loans, net of unearned income	16,647	19,898
Special Mention [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member]
Loans, net of unearned income	681	396
Special Mention [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member]
Loans, net of unearned income	9,355	9,196
Special Mention [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member]
Loans, net of unearned income	6,174	7,556
Special Mention [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans, net of unearned income	461	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	16	18
Substandard [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member]
Loans, net of unearned income	3,252	3,859
Substandard [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member]
Loans, net of unearned income	15,676	15,707
Substandard [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member]
Loans, net of unearned income	10,682	10,102
Substandard [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans, net of unearned income	425	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	0	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