Note 12 - Fair Value Measurements (Details) - Assets Measured at Fair Value on a Nonrecurring Basis - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	$ 905	$ 1,570
OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	2,946	14,445
Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	227	284
Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	857	8,123
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	678	946
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	475	863
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring		340
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	1,614	5,459
Fair Value, Inputs, Level 1 [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Fair Value, Inputs, Level 1 [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Fair Value, Inputs, Level 1 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring		0
Fair Value, Inputs, Level 1 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Fair Value, Inputs, Level 1 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Fair Value, Inputs, Level 1 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Fair Value, Inputs, Level 1 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring		0
Fair Value, Inputs, Level 1 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Fair Value, Inputs, Level 2 [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Fair Value, Inputs, Level 2 [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Fair Value, Inputs, Level 2 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring		0
Fair Value, Inputs, Level 2 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Fair Value, Inputs, Level 2 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Fair Value, Inputs, Level 2 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Fair Value, Inputs, Level 2 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring		0
Fair Value, Inputs, Level 2 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Fair Value, Inputs, Level 3 [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	905	1,570
Fair Value, Inputs, Level 3 [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	2,946	14,445
Fair Value, Inputs, Level 3 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	227	284
Fair Value, Inputs, Level 3 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	857	8,123
Fair Value, Inputs, Level 3 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	678	946
Fair Value, Inputs, Level 3 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	475	863
Fair Value, Inputs, Level 3 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring		340
Fair Value, Inputs, Level 3 [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	$ 1,614	$ 5,459