LOANS AND ALLOWANCE FOR LOAN LOSSES - Summary of Payment Status of Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	$ 10,831	$ 14,986
Current	1,644,872	1,644,549
Total Loans	1,655,703	1,659,535	$ 1,401,334
Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	7,663	6,712
Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	1,704	4,088
Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	1,464	4,186
Commercial and industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	260	968
Current	245,916	260,811
Total Loans	246,176	261,779	206,308
Commercial and industrial | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	173	209
Commercial and industrial | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	18	493
Commercial and industrial | Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	69	266
Construction and development
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	648	3,551
Current	250,204	233,952
Total Loans	250,852	237,503	193,909
Construction and development | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	648	735
Construction and development | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans		2,816
Commercial real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	4,719	5,033
Current	577,207	577,486
Total Loans	581,926	582,519	450,076
Commercial real estate | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	2,867	1,803
Commercial real estate | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	1,403	3
Commercial real estate | Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	449	3,227
Farmland
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	328	485
Current	71,946	67,360
Total Loans	72,274	67,845	63,971
Farmland | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	328	485
1-4 family residential
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	4,238	4,111
Current	386,380	388,956
Total Loans	390,618	393,067	377,278
1-4 family residential | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	3,067	2,849
1-4 family residential | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	263	666
1-4 family residential | Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	908	596
Multi-family residential
Financing Receivable Recorded Investment Past Due [Line Items]
Current	37,430	38,386
Total Loans	37,430	38,386	37,992
Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	540	633
Current	55,618	54,144
Total Loans	56,158	54,777	48,982
Consumer | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	482	526
Consumer | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	20	51
Consumer | Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	38	56
Agricultural
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	98	205
Current	19,896	23,072
Total Loans	19,994	23,277	22,545
Agricultural | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	98	105
Agricultural | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans		59
Agricultural | Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans		41
Overdrafts
Financing Receivable Recorded Investment Past Due [Line Items]
Current	275	382
Total Loans	$ 275	$ 382	$ 273