LOANS AND ALLOWANCE FOR LOAN LOSSES - Summary of Payment Status of Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	$ 11,615	$ 14,986
Current	1,682,232	1,644,549
Ending balance	1,693,847	1,659,535	$ 1,593,474
Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	5,538	6,712
Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	3,520	4,088
Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	2,557	4,186
Commercial and industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	915	968
Current	285,275	260,811
Ending balance	286,190	261,779	234,396
Commercial and industrial | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	897	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		266
Construction and development
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	1,222	3,551
Current	229,945	233,952
Ending balance	231,167	237,503	211,745
Construction and development | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	1,126	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
Construction and development | Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	96
Commercial real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	3,969	5,033
Current	588,976	577,486
Ending balance	592,945	582,519	570,448
Commercial real estate | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	700	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	1,729	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	1,540	3,227
Farmland
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	298	485
Current	70,711	67,360
Ending balance	71,009	67,845	68,272
Farmland | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	170	485
Farmland | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	128
1-4 family residential
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	4,268	4,111
Current	387,521	388,956
Ending balance	391,789	393,067	392,940
1-4 family residential | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	1,893	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	1,487	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	888	596
Multi-family residential
Financing Receivable Recorded Investment Past Due [Line Items]
Current	44,699	38,386
Ending balance	44,699	38,386	39,023
Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	682	633
Current	55,417	54,144
Ending balance	56,099	54,777	52,949
Consumer | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	544	526
Consumer | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	105	51
Consumer | Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	33	56
Agricultural
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	261	205
Current	19,460	23,072
Ending balance	19,721	23,277	23,362
Agricultural | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	208	105
Agricultural | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	53	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	228	382
Ending balance	$ 228	$ 382	$ 339