LOANS AND ALLOWANCE FOR LOAN LOSSES - Summary of Loan Portfolio by Type of Loan (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans held for investment:
Total loans	$ 1,659,535	$ 1,359,544	$ 1,243,925
Net deferred loan fees and costs	560	1,094
Allowance for loan losses	(14,651)	(12,859)	(11,484)	$ (9,263)
Total net loans	1,645,444	1,347,779
Commercial and industrial
Loans held for investment:
Total loans	261,779	197,508	223,712
Allowance for loan losses	(1,751)	(1,581)	(1,592)	(1,878)
Construction and development
Loans held for investment:
Total loans	237,503	196,774	129,631
Allowance for loan losses	(1,920)	(1,724)	(1,161)	(1,004)
Commercial real estate
Loans held for investment:
Total loans	582,519	418,137	368,077
Allowance for loan losses	(6,025)	(4,585)	(3,264)	(2,106)
Farmland
Loans held for investment:
Total loans	67,845	59,023	62,366
Allowance for loan losses	(643)	(523)	(482)	(400)
1-4 family residential
Loans held for investment:
Total loans	393,067	374,371	361,665
Allowance for loan losses	(2,868)	(3,022)	(3,960)	(2,839)
Multi-family residential
Loans held for investment:
Total loans	38,386	36,574	26,079
Allowance for loan losses	(631)	(629)	(281)	(325)
Consumer
Loans held for investment:
Total loans	54,777	51,267	53,177
Allowance for loan losses	(565)	(602)	(585)	(562)
Agricultural
Loans held for investment:
Total loans	23,277	25,596	18,901
Allowance for loan losses	(238)	(187)	(153)	(138)
Overdrafts
Loans held for investment:
Total loans	382	294	317
Allowance for loan losses	$ (10)	$ (6)	$ (6)	$ (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 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 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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