Note 7 - Loans and Allowance for Loan Losses (Details) - Risk Category of Loans by Class - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Credit risk profile by internally assigned rating grades:
Loans	$ 935,145	$ 931,943
Real Estate Portfolio Segment [Member]
Credit risk profile by internally assigned rating grades:
Loans	831,258	833,344
Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member]
Credit risk profile by internally assigned rating grades:
Loans	107,130	97,045
Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Pass [Member]
Credit risk profile by internally assigned rating grades:
Loans	92,979	81,438
Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Special Mention [Member]
Credit risk profile by internally assigned rating grades:
Loans	4,018	2,674
Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Substandard [Member]
Credit risk profile by internally assigned rating grades:
Loans	10,133	12,933
Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Doubtful [Member]
Credit risk profile by internally assigned rating grades:
Loans	0	0
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member]
Credit risk profile by internally assigned rating grades:
Loans	355,258	361,022
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Pass [Member]
Credit risk profile by internally assigned rating grades:
Loans	323,928	326,124
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Special Mention [Member]
Credit risk profile by internally assigned rating grades:
Loans	15,791	16,429
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Substandard [Member]
Credit risk profile by internally assigned rating grades:
Loans	15,539	18,469
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Doubtful [Member]
Credit risk profile by internally assigned rating grades:
Loans	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	368,870	375,277
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	327,195	327,019
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	24,191	27,855
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	17,484	19,941
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	0	462
Commercial Portfolio Segment [Member]
Credit risk profile by internally assigned rating grades:
Loans	91,858	85,186
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Credit risk profile by internally assigned rating grades:
Loans	51,187	47,112
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Pass [Member]
Credit risk profile by internally assigned rating grades:
Loans	49,697	45,665
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Special Mention [Member]
Credit risk profile by internally assigned rating grades:
Loans	999	946
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Substandard [Member]
Credit risk profile by internally assigned rating grades:
Loans	491	501
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Doubtful [Member]
Credit risk profile by internally assigned rating grades:
Loans	0	0
Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member]
Credit risk profile by internally assigned rating grades:
Loans	18,428	22,369
Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member] | Pass [Member]
Credit risk profile by internally assigned rating grades:
Loans	18,428	22,369
Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member] | Special Mention [Member]
Credit risk profile by internally assigned rating grades:
Loans	0	0
Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member] | Substandard [Member]
Credit risk profile by internally assigned rating grades:
Loans	0	0
Commercial Portfolio Segment [Member] | States and Political Subdivisions [Member] | Doubtful [Member]
Credit risk profile by internally assigned rating grades:
Loans	0	0
Commercial Portfolio Segment [Member] | Lease Financing [Member]
Credit risk profile by internally assigned rating grades:
Loans	25	158
Commercial Portfolio Segment [Member] | Lease Financing [Member] | Pass [Member]
Credit risk profile by internally assigned rating grades:
Loans	25	158
Commercial Portfolio Segment [Member] | Lease Financing [Member] | Special Mention [Member]
Credit risk profile by internally assigned rating grades:
Loans	0	0
Commercial Portfolio Segment [Member] | Lease Financing [Member] | Substandard [Member]
Credit risk profile by internally assigned rating grades:
Loans	0	0
Commercial Portfolio Segment [Member] | Lease Financing [Member] | Doubtful [Member]
Credit risk profile by internally assigned rating grades:
Loans	0	0
Commercial Portfolio Segment [Member] | Commercial Other [Member]
Credit risk profile by internally assigned rating grades:
Loans	22,218	15,547
Commercial Portfolio Segment [Member] | Commercial Other [Member] | Pass [Member]
Credit risk profile by internally assigned rating grades:
Loans	22,196	15,526
Commercial Portfolio Segment [Member] | Commercial Other [Member] | Special Mention [Member]
Credit risk profile by internally assigned rating grades:
Loans	0	14
Commercial Portfolio Segment [Member] | Commercial Other [Member] | Substandard [Member]
Credit risk profile by internally assigned rating grades:
Loans	22	7
Commercial Portfolio Segment [Member] | Commercial Other [Member] | Doubtful [Member]
Credit risk profile by internally assigned rating grades:
Loans	$ 0	$ 0