Note 4 - Loans Held for Investment - Loans Held for Investment (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Credit exposure by assigned risk grade	$ 701,443,000	$ 607,865,000
Loans held for investment, percent of total	100.00%	100.00%
Less deferred loan origination fees, net	$ 801,000	$ 850
Less allowance for loan and lease losses	8,673,172	7,866,523
Net loans held for investment	691,969,119	599,147,724
Residential Portfolio Segment [Member]
Credit exposure by assigned risk grade	$ 75,293,000	$ 72,320,000
Loans held for investment, percent of total	10.70%	11.90%
Residential Portfolio Segment [Member] \| Real Estate Loan [Member]
Credit exposure by assigned risk grade	$ 67,264,000	$ 68,229,000
Loans held for investment, percent of total	9.60%	11.20%
Residential Portfolio Segment [Member] \| Construction Loans [Member]
Credit exposure by assigned risk grade	$ 7,875,000	$ 3,934,000
Loans held for investment, percent of total	1.10%	0.60%
Residential Portfolio Segment [Member] \| Lots and Raw Land [Member]
Credit exposure by assigned risk grade	$ 154,000	$ 157,000
Loans held for investment, percent of total	0.00%	0.10%
Residential Portfolio Segment [Member] \| Lease Receivables [Member]
Credit exposure by assigned risk grade	$ 21,236,000	$ 17,235,000
Commercial Portfolio Segment [Member]
Credit exposure by assigned risk grade	$ 556,941,000	$ 472,688,000
Loans held for investment, percent of total	79.40%	77.80%
Commercial Portfolio Segment [Member] \| Real Estate Loan [Member]
Credit exposure by assigned risk grade	$ 378,173,000	$ 338,714,000
Loans held for investment, percent of total	53.90%	55.70%
Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Credit exposure by assigned risk grade	$ 56,118,000	$ 42,987,000
Loans held for investment, percent of total	8.00%	7.10%
Commercial Portfolio Segment [Member] \| Lots and Raw Land [Member]
Credit exposure by assigned risk grade	$ 33,434,000	$ 28,271,000
Loans held for investment, percent of total	4.80%	4.70%
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member]
Credit exposure by assigned risk grade	$ 67,980,000	$ 45,481,000
Loans held for investment, percent of total	9.70%	7.50%
Commercial Portfolio Segment [Member] \| Lease Receivables [Member]
Credit exposure by assigned risk grade	$ 21,236,000	$ 17,235,000
Loans held for investment, percent of total	3.00%	2.80%
Consumer Portfolio Segment [Member]
Credit exposure by assigned risk grade	$ 69,209,000	$ 62,857,000
Loans held for investment, percent of total	9.90%	10.30%
Consumer Portfolio Segment [Member] \| Real Estate Loan [Member]
Credit exposure by assigned risk grade	$ 16,967,000	$ 17,239,000
Loans held for investment, percent of total	2.40%	2.80%
Consumer Portfolio Segment [Member] \| Construction Loans [Member]
Credit exposure by assigned risk grade	$ 105,000	$ 196,000
Loans held for investment, percent of total	0.00%	0.10%
Consumer Portfolio Segment [Member] \| Lots and Raw Land [Member]
Credit exposure by assigned risk grade	$ 8,975,000	$ 9,643,000
Consumer Portfolio Segment [Member] \| Lease Receivables [Member]
Credit exposure by assigned risk grade	$ 8,975,000	$ 9,643,000
Loans held for investment, percent of total	1.30%	1.60%
Consumer Portfolio Segment [Member] \| Home Equity Loan [Member]
Credit exposure by assigned risk grade	$ 36,815,000	$ 29,709,000
Loans held for investment, percent of total	5.30%	4.80%
Consumer Portfolio Segment [Member] \| Other Loans [Member]
Credit exposure by assigned risk grade	$ 6,347,000	$ 6,070,000
Loans held for investment, percent of total	0.90%	1.00%

Total percent of loans held for investment.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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