LOANS AND ALLOWANCE FOR LOAN LOSSES - Summary of Loan Portfolio by Type of Loan (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Loans held for investment:
Total loans	$ 1,307,375	$ 1,245,135	$ 1,229,341
Less: Allowance for loan losses	12,528	11,484	11,166	$ 9,263
Total net loans	1,294,847	1,233,651
Unamortized loan costs, net of loan fees	1,089	1,210
Commercial and industrial
Loans held for investment:
Total loans	192,663	223,997	224,617
Less: Allowance for loan losses	1,573	1,592	1,645	1,878
Construction and development
Loans held for investment:
Total loans	201,067	129,366	125,045
Less: Allowance for loan losses	1,923	1,161	1,133	1,004
Commercial real estate
Loans held for investment:
Total loans	393,314	367,656	360,676
Less: Allowance for loan losses	4,199	3,264	3,099	2,106
Farmland
Loans held for investment:
Total loans	54,349	62,362	61,902
Less: Allowance for loan losses	458	482	474	400
1-4 family residential
Loans held for investment:
Total loans	365,889	362,952	348,401
Less: Allowance for loan losses	3,089	3,960	3,730	2,839
Multi-family residential
Loans held for investment:
Total loans	23,235	26,079	34,538
Less: Allowance for loan losses	266	281	371	325
Consumer
Loans held for investment:
Total loans	51,711	53,505	54,345
Less: Allowance for loan losses	599	585	569	562
Agricultural
Loans held for investment:
Total loans	24,449	18,901	19,223
Less: Allowance for loan losses	407	153	128	138
Overdrafts
Loans held for investment:
Total loans	698	317	594
Less: Allowance for loan losses	$ 14	$ 6	$ 17	$ 11

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 before allowance and after 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.

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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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Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.

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