Note 12 - Fair Value Measurements (Details) - Assets Measured at Fair Value on a Nonrecurring Basis - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	$ 93	$ 6,628
OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	2,879	5,526
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 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 3 [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	93	6,628
Fair Value, Inputs, Level 3 [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	2,879	5,526
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	88	3,720
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	14	406
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	5
Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	423	2,868
Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring		2,908
Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	2,442	2,252
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 1 [Member] | Real Estate Mortgage Residential [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 1 [Member] | Real Estate Mortgage Residential [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 1 [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 1 [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 1 [Member] | Real Estate Construction and Land Development [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring		0
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 1 [Member] | Real Estate Construction and Land Development [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 2 [Member] | Real Estate Mortgage Residential [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 2 [Member] | Real Estate Mortgage Residential [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 2 [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 2 [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 2 [Member] | Real Estate Construction and Land Development [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring		0
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 2 [Member] | Real Estate Construction and Land Development [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	0	0
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member] | Real Estate Mortgage Residential [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	88	3,720
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member] | Real Estate Mortgage Residential [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	14	406
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	5
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	423	2,868
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member] | Real Estate Construction and Land Development [Member] | Impaired Loans [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring		2,908
Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member] | Real Estate Construction and Land Development [Member] | OREO [Member]
Collateral-dependent Impaired Loans
Assets fair value, nonrecurring	$ 2,442	$ 2,252