LOANS AND ALLOWANCE FOR LOAN LOSSES - Summary of Loan Portfolio by Type of Loan (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Loans held for investment:
Total loans	$ 1,593,474	$ 1,359,544	$ 1,296,843
Deferred loan fees	857	1,094
Less: Allowance for loan losses	(13,890)	(12,859)	(12,525)	$ (11,484)
Total net loans	1,580,441	1,347,779
Commercial and industrial
Loans held for investment:
Total loans	234,396	197,508	217,497
Less: Allowance for loan losses	(1,742)	(1,581)	(2,008)	(1,592)
Construction and development
Loans held for investment:
Total loans	211,745	196,774	177,600
Less: Allowance for loan losses	(1,642)	(1,724)	(1,554)	(1,161)
Commercial real estate
Loans held for investment:
Total loans	570,448	418,137	378,722
Less: Allowance for loan losses	(5,556)	(4,585)	(3,464)	(3,264)
Farmland
Loans held for investment:
Total loans	68,272	59,023	63,839
Less: Allowance for loan losses	(648)	(523)	(541)	(482)
1-4 family residential
Loans held for investment:
Total loans	392,940	374,371	356,457
Less: Allowance for loan losses	(2,832)	(3,022)	(3,726)	(3,960)
Multi-family residential
Loans held for investment:
Total loans	39,023	36,574	28,833
Less: Allowance for loan losses	(698)	(629)	(269)	(281)
Consumer
Loans held for investment:
Total loans	52,949	51,267	51,677
Less: Allowance for loan losses	(522)	(602)	(585)	(585)
Agricultural
Loans held for investment:
Total loans	23,362	25,596	21,854
Less: Allowance for loan losses	(238)	(187)	(371)	(153)
Overdrafts
Loans held for investment:
Total loans	339	294	364
Less: Allowance for loan losses	$ (12)	$ (6)	$ (7)	$ (6)

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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