LOANS AND ALLOWANCE FOR LOAN LOSSES - Summary of Payment Status of Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	$ 12,063	$ 14,986
Current	1,724,376	1,644,549
Ending balance	1,736,439	1,659,535	$ 1,651,863
Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	9,602	6,712
Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	1,337	4,088
Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	1,124	4,186
Commercial and industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	752	968
Current	298,962	260,811
Ending balance	299,714	261,779	248,758
Commercial and industrial | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	664	209
Commercial and industrial | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	88	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	1,597	3,551
Current	254,862	233,952
Ending balance	256,459	237,503	229,307
Construction and development | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	1,498	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	99
Commercial real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	2,759	5,033
Current	578,983	577,486
Ending balance	581,742	582,519	599,153
Commercial real estate | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	1,960	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	278	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	521	3,227
Farmland
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	255	485
Current	60,818	67,360
Ending balance	61,073	67,845	65,209
Farmland | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	255	485
1-4 family residential
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	6,123	4,111
Current	400,757	388,956
Ending balance	406,880	393,067	392,456
1-4 family residential | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	4,819	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	890	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	414	596
Multi-family residential
Financing Receivable Recorded Investment Past Due [Line Items]
Current	58,198	38,386
Ending balance	58,198	38,386	38,523
Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	512	633
Current	52,803	54,144
Ending balance	53,315	54,777	53,947
Consumer | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	341	526
Consumer | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	81	51
Consumer | Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	90	56
Agricultural
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	65	205
Current	18,663	23,072
Ending balance	18,728	23,277	24,184
Agricultural | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due loans	65	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	330	382
Ending balance	$ 330	$ 382	$ 326