LOANS AND ALLOWANCE FOR CREDIT LOSSES - Summary of Credit Exposure in Company Loan Portfolio (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($)
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	$ 618,973
Credit Exposure 2019	331,609
Credit Exposure 2018	235,676
Credit Exposure 2017	174,863
Credit Exposure 2016	182,117
Credit Exposure Prior	296,098
Revolving Loans Amortized Cost	119,298
Total	1,958,634
Credit Exposure 2020.Charge - offs	(128)
Credit Exposure 2019.Charge - offs	(61)
Credit Exposure 2018.Charge - offs	(88)
Credit Exposure 2017.Charge - offs	(41)
Credit Exposure 2016.Charge - offs	(3)
Credit Exposure Prior.Charge - offs	(63)
Total	(384)
Credit Exposure 2020, Recoveries	41
Credit Exposure 2019, Recoveries	2
Credit Exposure 2018, Recoveries	55
Credit Exposure 2017, Recoveries	8
Credit Exposure 2016, Recoveries	23
Credit Exposure Prior, Recoveries	26
Credit Exposure Revolving Loans Amortized Cost, Recoveries	36
Total	191
Credit Exposure 2020,Current period net	(87)
Credit Exposure 2019,Current period net	(59)
Credit Exposure 2018,Current period net	(33)
Credit Exposure 2017,Current period net	(33)
Credit Exposure 2016,Current period net	20
Credit Exposure Prior,Current period net	(37)
Credit Exposure Revolving Loans Amortized Cost,Current period net	36
Total	(193)
Pass
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	615,790
Credit Exposure 2019	324,611
Credit Exposure 2018	228,884
Credit Exposure 2017	159,930
Credit Exposure 2016	170,488
Credit Exposure Prior	284,690
Revolving Loans Amortized Cost	119,141
Total	1,903,534
Special Mention
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	267
Credit Exposure 2019	5,144
Credit Exposure 2018	3,593
Credit Exposure 2017	9,917
Credit Exposure 2016	3,819
Credit Exposure Prior	962
Revolving Loans Amortized Cost	150
Total	23,852
Substandard
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	2,907
Credit Exposure 2019	609
Credit Exposure 2018	2,239
Credit Exposure 2017	437
Credit Exposure 2016	2,848
Credit Exposure Prior	8,428
Total	17,468
Nonaccrual
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	9
Credit Exposure 2019	1,245
Credit Exposure 2018	960
Credit Exposure 2017	4,579
Credit Exposure 2016	4,962
Credit Exposure Prior	2,018
Revolving Loans Amortized Cost	7
Total	13,780
Commercial and industrial
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	361,379
Credit Exposure 2019	35,275
Credit Exposure 2018	16,779
Credit Exposure 2017	10,775
Credit Exposure 2016	8,574
Credit Exposure Prior	17,740
Revolving Loans Amortized Cost	80,630
Total	531,152
Credit Exposure 2018.Charge - offs	(43)
Total	(43)
Credit Exposure 2018, Recoveries	43
Credit Exposure Prior, Recoveries	14
Credit Exposure Revolving Loans Amortized Cost, Recoveries	36
Total	93
Credit Exposure Prior,Current period net	14
Credit Exposure Revolving Loans Amortized Cost,Current period net	36
Total	50
Commercial and industrial | Pass
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	361,379
Credit Exposure 2019	35,265
Credit Exposure 2018	16,564
Credit Exposure 2017	7,252
Credit Exposure 2016	7,194
Credit Exposure Prior	17,740
Revolving Loans Amortized Cost	80,480
Total	525,874
Commercial and industrial | Special Mention
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2017	3,523
Credit Exposure 2016	1,324
Revolving Loans Amortized Cost	150
Total	4,997
Commercial and industrial | Substandard
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2018	210
Credit Exposure 2016	56
Total	266
Commercial and industrial | Nonaccrual
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2019	10
Credit Exposure 2018	5
Total	15
Construction and development
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	93,863
Credit Exposure 2019	93,542
Credit Exposure 2018	30,146
Credit Exposure 2017	26,993
Credit Exposure 2016	9,433
Credit Exposure Prior	10,585
Revolving Loans Amortized Cost	4,539
Total	269,101
Construction and development | Pass
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	90,694
Credit Exposure 2019	92,719
Credit Exposure 2018	29,841
Credit Exposure 2017	25,992
Credit Exposure 2016	8,753
Credit Exposure Prior	10,585
Revolving Loans Amortized Cost	4,539
Total	263,123
Construction and development | Special Mention
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	262
Credit Exposure 2019	164
Credit Exposure 2017	1,001
Total	1,427
Construction and development | Substandard
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	2,907
Credit Exposure 2019	609
Credit Exposure 2018	5
Credit Exposure 2016	680
Total	4,201
Construction and development | Nonaccrual
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2019	50
Credit Exposure 2018	300
Total	350
Commercial real estate
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	59,513
Credit Exposure 2019	104,823
Credit Exposure 2018	104,779
Credit Exposure 2017	85,332
Credit Exposure 2016	103,617
Credit Exposure Prior	138,251
Revolving Loans Amortized Cost	6,349
Total	602,664
Credit Exposure Prior, Recoveries	1
Total	1
Credit Exposure Prior,Current period net	1
Total	1
Commercial real estate | Pass
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	59,513
Credit Exposure 2019	98,704
Credit Exposure 2018	99,042
Credit Exposure 2017	75,436
Credit Exposure 2016	94,333
Credit Exposure Prior	128,363
Revolving Loans Amortized Cost	6,349
Total	561,740
Commercial real estate | Special Mention
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2019	4,979
Credit Exposure 2018	3,570
Credit Exposure 2017	5,335
Credit Exposure 2016	2,495
Credit Exposure Prior	914
Total	17,293
Commercial real estate | Substandard
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2018	2,014
Credit Exposure 2017	437
Credit Exposure 2016	2,038
Credit Exposure Prior	8,293
Total	12,782
Commercial real estate | Nonaccrual
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2019	1,140
Credit Exposure 2018	153
Credit Exposure 2017	4,124
Credit Exposure 2016	4,751
Credit Exposure Prior	681
Total	10,849
Farmland
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	13,842
Credit Exposure 2019	12,939
Credit Exposure 2018	11,854
Credit Exposure 2017	7,382
Credit Exposure 2016	11,014
Credit Exposure Prior	17,883
Revolving Loans Amortized Cost	5,283
Total	80,197
Farmland | Pass
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	13,842
Credit Exposure 2019	12,939
Credit Exposure 2018	11,854
Credit Exposure 2017	7,382
Credit Exposure 2016	11,014
Credit Exposure Prior	17,591
Revolving Loans Amortized Cost	5,283
Total	79,905
Farmland | Special Mention
Financing Receivable Recorded Investment [Line Items]
Credit Exposure Prior	37
Total	37
Farmland | Substandard
Financing Receivable Recorded Investment [Line Items]
Credit Exposure Prior	135
Total	135
Farmland | Nonaccrual
Financing Receivable Recorded Investment [Line Items]
Credit Exposure Prior	120
Total	120
1-4 family residential
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	63,466
Credit Exposure 2019	64,012
Credit Exposure 2018	55,048
Credit Exposure 2017	39,824
Credit Exposure 2016	46,370
Credit Exposure Prior	106,283
Revolving Loans Amortized Cost	10,780
Total	385,783
Credit Exposure Prior.Charge - offs	(59)
Total	(59)
Credit Exposure Prior, Recoveries	2
Total	2
Credit Exposure Prior,Current period net	(57)
Total	(57)
1-4 family residential | Pass
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	63,466
Credit Exposure 2019	64,012
Credit Exposure 2018	54,716
Credit Exposure 2017	39,389
Credit Exposure 2016	46,163
Credit Exposure Prior	105,068
Revolving Loans Amortized Cost	10,780
Total	383,594
1-4 family residential | Nonaccrual
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2018	332
Credit Exposure 2017	435
Credit Exposure 2016	207
Credit Exposure Prior	1,215
Total	2,189
Multi-family residential
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	4,180
Credit Exposure 2019	4,528
Credit Exposure 2018	2,913
Credit Exposure 2017	1,408
Credit Exposure 2016	1,758
Credit Exposure Prior	4,503
Revolving Loans Amortized Cost	209
Total	19,499
Multi-family residential | Pass
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	4,180
Credit Exposure 2019	4,528
Credit Exposure 2018	2,913
Credit Exposure 2017	1,408
Credit Exposure 2016	1,758
Credit Exposure Prior	4,503
Revolving Loans Amortized Cost	209
Total	19,499
Consumer and Overdrafts
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	19,954
Credit Exposure 2019	14,512
Credit Exposure 2018	11,583
Credit Exposure 2017	2,324
Credit Exposure 2016	941
Credit Exposure Prior	628
Revolving Loans Amortized Cost	3,292
Total	53,234
Credit Exposure 2020.Charge - offs	(128)
Credit Exposure 2019.Charge - offs	(61)
Credit Exposure 2018.Charge - offs	(27)
Credit Exposure 2017.Charge - offs	(41)
Credit Exposure 2016.Charge - offs	(3)
Credit Exposure Prior.Charge - offs	(4)
Total	(264)
Credit Exposure 2020, Recoveries	41
Credit Exposure 2019, Recoveries	2
Credit Exposure 2018, Recoveries	12
Credit Exposure 2017, Recoveries	8
Credit Exposure 2016, Recoveries	3
Credit Exposure Prior, Recoveries	9
Total	75
Credit Exposure 2020,Current period net	(87)
Credit Exposure 2019,Current period net	(59)
Credit Exposure 2018,Current period net	(15)
Credit Exposure 2017,Current period net	(33)
Credit Exposure Prior,Current period net	5
Total	(189)
Consumer and Overdrafts | Pass
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	19,940
Credit Exposure 2019	14,466
Credit Exposure 2018	11,420
Credit Exposure 2017	2,297
Credit Exposure 2016	937
Credit Exposure Prior	617
Revolving Loans Amortized Cost	3,292
Total	52,969
Consumer and Overdrafts | Special Mention
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	5
Credit Exposure 2019	1
Credit Exposure 2018	23
Credit Exposure 2017	7
Credit Exposure Prior	11
Total	47
Consumer and Overdrafts | Nonaccrual
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	9
Credit Exposure 2019	45
Credit Exposure 2018	140
Credit Exposure 2017	20
Credit Exposure 2016	4
Total	218
Agricultural
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	2,776
Credit Exposure 2019	1,978
Credit Exposure 2018	2,574
Credit Exposure 2017	825
Credit Exposure 2016	410
Credit Exposure Prior	225
Revolving Loans Amortized Cost	8,216
Total	17,004
Credit Exposure 2018.Charge - offs	(18)
Total	(18)
Credit Exposure 2016, Recoveries	20
Total	20
Credit Exposure 2018,Current period net	(18)
Credit Exposure 2016,Current period net	20
Total	2
Agricultural | Pass
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2020	2,776
Credit Exposure 2019	1,978
Credit Exposure 2018	2,534
Credit Exposure 2017	774
Credit Exposure 2016	336
Credit Exposure Prior	223
Revolving Loans Amortized Cost	8,209
Total	16,830
Agricultural | Special Mention
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2017	51
Total	51
Agricultural | Substandard
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2018	10
Credit Exposure 2016	74
Total	84
Agricultural | Nonaccrual
Financing Receivable Recorded Investment [Line Items]
Credit Exposure 2018	30
Credit Exposure Prior	2
Revolving Loans Amortized Cost	7
Total	$ 39