Note 7 - Loans and Allowance for Loan Losses (Details) - Risk Category of Loans by Class - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Credit risk profile by internally assigned rating grades
Loans by risk rating	$ 962,289	$ 959,275
Real Estate Portfolio Segment [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	862,915	857,036
Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	123,093	115,516
Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Pass [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	113,284	104,383
Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Special Mention [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	1,469	1,651
Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Substandard [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	8,340	9,482
Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Doubtful [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	0	0
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	349,725	355,134
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Pass [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	320,150	324,333
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Special Mention [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	15,443	16,225
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Substandard [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	14,132	14,576
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Doubtful [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	0	0
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	390,097	386,386
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Pass [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	349,944	343,894
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Special Mention [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	21,391	22,859
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Substandard [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	18,762	19,633
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Doubtful [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	0	0
Commercial Portfolio Segment [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	89,803	89,820
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	48,243	48,379
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Pass [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	46,908	46,934
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Special Mention [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	819	937
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Substandard [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	516	508
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Doubtful [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	0	0
Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	20,013	17,643
Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member] | Pass [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	20,013	17,643
Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member] | Special Mention [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	0	0
Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member] | Substandard [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	0	0
Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member] | Doubtful [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	0	0
Commercial Portfolio Segment [Member] | Commercial Other [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	21,547	23,798
Commercial Portfolio Segment [Member] | Commercial Other [Member] | Pass [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	21,541
Commercial Portfolio Segment [Member] | Commercial Other [Member] | Special Mention [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	0
Commercial Portfolio Segment [Member] | Commercial Other [Member] | Substandard [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	6
Commercial Portfolio Segment [Member] | Commercial Other [Member] | Doubtful [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating	$ 0
Commercial Portfolio Segment [Member] | Lease Financing [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating		23,798
Commercial Portfolio Segment [Member] | Lease Financing [Member] | Pass [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating		23,777
Commercial Portfolio Segment [Member] | Lease Financing [Member] | Special Mention [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating		0
Commercial Portfolio Segment [Member] | Lease Financing [Member] | Substandard [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating		21
Commercial Portfolio Segment [Member] | Lease Financing [Member] | Doubtful [Member]
Credit risk profile by internally assigned rating grades
Loans by risk rating		$ 0