Note 12 - Fair Value Measurements - Assets Measured At Fair Value On a Nonrecurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Impaired Loans [Member]
Fair Value	$ 1,723	$ 6,397
Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value	0	0
Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value	0	0
Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value	1,723	6,397
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member]
Fair Value	1,315	2,909
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value	0	0
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value	0	0
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value	1,315	2,909
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member]
Fair Value	395	3,137
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value	0	0
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value	0	0
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value	395	3,137
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member]
Fair Value	13	351
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value	0	0
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value	0	0
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value	13	351
OREO [Member]
Fair Value	3,407	6,187
OREO [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value	0	0
OREO [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value	0	0
OREO [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value	3,407	6,187
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member]
Fair Value	2,588	4,883
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value	0	0
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value	0	0
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value	2,588	4,883
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member]
Fair Value	90	234
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value	0	0
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value	0	0
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value	90	234
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member]
Fair Value	729	1,070
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value	0	0
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value	0	0
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value	$ 729	$ 1,070