Note 12 - Fair Value Measurements - Assets Measured at Fair Value on a Nonrecurring Basis (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Fair Value, Inputs, Level 1 [Member]
Assets fair value, nonrecurring	$ 0
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Fair Value, Inputs, Level 2 [Member]
Assets fair value, nonrecurring	0
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Fair Value, Inputs, Level 3 [Member]
Assets fair value, nonrecurring	168,000
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member]
Assets fair value, nonrecurring	168,000
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Fair Value, Inputs, Level 1 [Member]
Assets fair value, nonrecurring		$ 0
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Fair Value, Inputs, Level 2 [Member]
Assets fair value, nonrecurring		0
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Fair Value, Inputs, Level 3 [Member]
Assets fair value, nonrecurring		2,908,000
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member]
Assets fair value, nonrecurring		2,908,000
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Fair Value, Inputs, Level 1 [Member]
Assets fair value, nonrecurring		0
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Fair Value, Inputs, Level 2 [Member]
Assets fair value, nonrecurring		0
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Fair Value, Inputs, Level 3 [Member]
Assets fair value, nonrecurring		3,720,000
Impaired Loans [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member]
Assets fair value, nonrecurring		3,720,000
Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets fair value, nonrecurring	0	0
Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets fair value, nonrecurring	0	0
Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets fair value, nonrecurring	168,000	6,628,000
Impaired Loans [Member]
Assets fair value, nonrecurring	168,000	6,628,000
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Fair Value, Inputs, Level 1 [Member]
Assets fair value, nonrecurring	0	0
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Fair Value, Inputs, Level 2 [Member]
Assets fair value, nonrecurring	0	0
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member] | Fair Value, Inputs, Level 3 [Member]
Assets fair value, nonrecurring	1,202,000	2,868,000
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Farmland and Other Commercial Enterprises [Member]
Assets fair value, nonrecurring	1,202,000	2,868,000
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Fair Value, Inputs, Level 1 [Member]
Assets fair value, nonrecurring	0	0
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Fair Value, Inputs, Level 2 [Member]
Assets fair value, nonrecurring	0	0
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member] | Fair Value, Inputs, Level 3 [Member]
Assets fair value, nonrecurring	2,170,000	2,252,000
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Construction and Land Development [Member]
Assets fair value, nonrecurring	2,170,000	2,252,000
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Fair Value, Inputs, Level 1 [Member]
Assets fair value, nonrecurring	0	0
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Fair Value, Inputs, Level 2 [Member]
Assets fair value, nonrecurring	0	0
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member] | Fair Value, Inputs, Level 3 [Member]
Assets fair value, nonrecurring	69,000	406,000
OREO [Member] | Real Estate Portfolio Segment [Member] | Real Estate Mortgage Residential [Member]
Assets fair value, nonrecurring	69,000	406,000
OREO [Member] | Fair Value, Inputs, Level 1 [Member]
Assets fair value, nonrecurring	0	0
OREO [Member] | Fair Value, Inputs, Level 2 [Member]
Assets fair value, nonrecurring	0	0
OREO [Member] | Fair Value, Inputs, Level 3 [Member]
Assets fair value, nonrecurring	3,441,000	5,526,000
OREO [Member]
Assets fair value, nonrecurring	$ 3,441,000	$ 5,526,000