ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Risk Category of Loans by Loan Segment and Origination (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	$ 198,443		$ 846,498
Year Two	828,644		755,972
Year Three	740,454		558,989
Year Four	573,009		464,644
Year Five	443,812		221,160
Prior	448,282		293,243
Term Total	3,232,644		3,140,506
Revolving	1,764,915		1,776,028
Total	4,997,559		4,916,534
Year One	1		16
Year Two	73		5,753
Year Three	230		179
Year Four	20		186
Year Five	0		480
Prior	26		1
Term Total	350		6,615
Revolving	154		717
Total	504	$ 5,896	7,332
Other commercial loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	150		7,058
Year Two	6,798		26,918
Year Three	26,338		33,247
Year Four	33,783		13,684
Year Five	13,061		90
Prior	8,942		9,751
Term Total	89,072		90,748
Revolving	31,102		29,819
Total	120,174		120,567
Working capital lines of credit loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		0
Year Three	94		75
Year Four	0		0
Year Five	0		139
Prior	0		0
Term Total	94		214
Revolving	87		327
Total	181		541
Working capital lines of credit loans | Commercial and industrial loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		193
Year Two	173		2,076
Year Three	1,910		2,214
Year Four	2,085		1,132
Year Five	1,014		125
Prior	125		50
Term Total	5,307		5,790
Revolving	641,149		599,100
Total	646,456		604,890
Non-working capital loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		5,445
Year Three	0		0
Year Four	0		178
Year Five	0		129
Prior	0		0
Term Total	0		5,752
Revolving	13		48
Total	13		5,800
Non-working capital loans | Commercial and industrial loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	30,140		209,448
Year Two	215,171		237,521
Year Three	213,457		87,888
Year Four	82,727		57,096
Year Five	52,309		31,292
Prior	40,983		15,035
Term Total	634,787		638,280
Revolving	195,521		177,138
Total	830,308		815,418
Construction and land development loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		0
Year Three	0		0
Year Four	0		0
Year Five	0		0
Prior	0		0
Term Total	0		0
Revolving	0		0
Total	0		0
Construction and land development loans | Commercial Real Estate and Multifamily Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	19,348		50,693
Year Two	43,392		15,558
Year Three	12,546		17,655
Year Four	47,129		0
Year Five	0		177
Prior	175		0
Term Total	122,590		84,083
Revolving	534,622		547,570
Total	657,212		631,653
Owner occupied loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		0
Year Three	0		0
Year Four	0		0
Year Five	0		0
Prior	0		0
Term Total	0		0
Revolving	0		0
Total	0		0
Owner occupied loans | Commercial Real Estate and Multifamily Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	11,403		152,370
Year Two	149,338		133,786
Year Three	148,534		164,918
Year Four	161,000		133,881
Year Five	129,731		63,154
Prior	173,877		121,812
Term Total	773,883		769,921
Revolving	58,965		55,027
Total	832,848		824,948
Nonowner occupied loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		0
Year Three	0		0
Year Four	0		0
Year Five	0		0
Prior	0		0
Term Total	0		0
Revolving	0		0
Total	0		0
Nonowner occupied loans | Commercial Real Estate and Multifamily Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	57,316		128,136
Year Two	138,228		158,415
Year Three	156,608		118,839
Year Four	116,706		134,050
Year Five	127,439		87,288
Prior	118,205		69,001
Term Total	714,502		695,729
Revolving	29,333		27,860
Total	743,835		723,589
Multifamily loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		0
Year Three	0		0
Year Four	0		0
Year Five	0		0
Prior	0		0
Term Total	0		0
Revolving	0		0
Total	0		0
Multifamily loans | Commercial Real Estate and Multifamily Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	51,604		110,625
Year Two	90,723		23,315
Year Three	22,315		9,042
Year Four	8,985		35,648
Year Five	35,305		13,971
Prior	24,943		14,609
Term Total	233,875		207,210
Revolving	5,804		45,987
Total	239,679		253,197
Loans secured by farmland
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		0
Year Three	0		0
Year Four	0		0
Year Five	0		0
Prior	0		0
Term Total	0		0
Revolving	0		0
Total	0		0
Loans secured by farmland | Agri-business and agricultural loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	3,516		24,503
Year Two	23,636		32,060
Year Three	31,737		25,308
Year Four	24,413		27,924
Year Five	27,560		9,104
Prior	25,204		19,260
Term Total	136,066		138,159
Revolving	31,201		24,724
Total	167,267		162,883
Loans for agricultural production
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		0
Year Three	0		0
Year Four	0		0
Year Five	0		0
Prior	0		0
Term Total	0		0
Revolving	0		0
Total	0		0
Loans for agricultural production | Agri-business and agricultural loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	1,142		28,657
Year Two	28,938		13,589
Year Three	19,910		27,362
Year Four	26,596		25,504
Year Five	24,782		3,533
Prior	12,545		10,429
Term Total	113,913		109,074
Revolving	86,770		116,906
Total	200,683		225,980
Other commercial loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		0
Year Three	0		0
Year Four	0		0
Year Five	0		0
Prior	0		0
Term Total	0		0
Revolving	0		0
Total	0		0
Closed end first mortgage loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		0
Year Three	0		0
Year Four	0		0
Year Five	0		0
Prior	0		0
Term Total	0		0
Revolving	0		0
Total	0		0
Closed end first mortgage loans | Consumer 1-4 Family Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	9,799		74,230
Year Two	74,928		61,559
Year Three	59,863		50,596
Year Four	49,727		26,688
Year Five	24,550		8,238
Prior	34,936		28,103
Term Total	253,803		249,414
Revolving	6,473		8,330
Total	260,276		257,744
Open end and junior lien loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		50
Year Three	0		14
Year Four	0		0
Year Five	0		0
Prior	0		0
Term Total	0		64
Revolving	0		99
Total	0		163
Open end and junior lien loans | Consumer 1-4 Family Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	5,616		25,457
Year Two	23,328		29,785
Year Three	26,949		8,985
Year Four	7,965		1,889
Year Five	1,615		2,312
Prior	3,930		2,016
Term Total	69,403		70,444
Revolving	121,449		121,128
Total	190,852		191,572
Residential construction loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		0
Year Three	0		0
Year Four	0		0
Year Five	0		0
Prior	0		0
Term Total	0		0
Revolving	0		0
Total	0		0
Residential construction loans: | Consumer 1-4 Family Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	681		1,525
Year Two	2,712		2,982
Year Three	3,726		1,515
Year Four	1,473		839
Year Five	819		263
Prior	1,465		1,220
Term Total	10,876		8,344
Revolving	0		0
Total	10,876		8,344
Other consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	1		16
Year Two	73		258
Year Three	136		90
Year Four	20		8
Year Five	0		212
Prior	26		1
Term Total	256		585
Revolving	54		243
Total	310		828
Other consumer loans | Consumer 1-4 Family Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	7,728		33,603
Year Two	31,279		18,408
Year Three	16,561		11,420
Year Four	10,420		6,309
Year Five	5,627		1,613
Prior	2,952		1,957
Term Total	74,567		73,310
Revolving	22,526		22,439
Total	97,093		95,749
Pass | Other commercial loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	150		7,058
Year Two	6,798		26,918
Year Three	26,338		33,247
Year Four	33,783		13,684
Year Five	13,061		90
Prior	6,712		7,332
Term Total	86,842		88,329
Revolving	31,102		29,819
Total	117,944		118,148
Pass | Working capital lines of credit loans | Commercial and industrial loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		193
Year Two	173		1,876
Year Three	1,910		2,214
Year Four	2,085		1,132
Year Five	1,014		0
Prior	0		50
Term Total	5,182		5,465
Revolving	578,879		532,086
Total	584,061		537,551
Pass | Non-working capital loans | Commercial and industrial loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	29,281		199,071
Year Two	205,939		224,333
Year Three	199,954		85,273
Year Four	80,369		49,999
Year Five	46,724		28,773
Prior	35,984		10,501
Term Total	598,251		597,950
Revolving	190,808		171,264
Total	789,059		769,214
Pass | Construction and land development loans | Commercial Real Estate and Multifamily Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	19,348		50,693
Year Two	43,392		15,558
Year Three	12,546		17,655
Year Four	47,129		0
Year Five	0		177
Prior	175		0
Term Total	122,590		84,083
Revolving	534,622		547,570
Total	657,212		631,653
Pass | Owner occupied loans | Commercial Real Estate and Multifamily Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	11,403		144,411
Year Two	141,477		132,850
Year Three	133,033		156,680
Year Four	153,999		132,407
Year Five	128,260		61,415
Prior	168,796		118,406
Term Total	736,968		746,169
Revolving	58,965		40,288
Total	795,933		786,457
Pass | Nonowner occupied loans | Commercial Real Estate and Multifamily Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	56,730		123,633
Year Two	133,775		158,415
Year Three	156,608		112,582
Year Four	110,545		134,050
Year Five	127,439		87,288
Prior	115,982		66,755
Term Total	701,079		682,723
Revolving	29,333		27,860
Total	730,412		710,583
Pass | Multifamily loans | Commercial Real Estate and Multifamily Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	21,016		90,954
Year Two	90,723		23,315
Year Three	22,315		9,042
Year Four	8,985		35,648
Year Five	35,305		13,971
Prior	24,943		14,609
Term Total	203,287		187,539
Revolving	5,804		45,987
Total	209,091		233,526
Pass | Loans secured by farmland | Agri-business and agricultural loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	3,516		24,503
Year Two	23,636		32,060
Year Three	31,737		25,308
Year Four	24,413		27,924
Year Five	27,560		9,104
Prior	25,108		19,160
Term Total	135,970		138,059
Revolving	31,201		24,724
Total	167,171		162,783
Pass | Loans for agricultural production | Agri-business and agricultural loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	1,142		28,657
Year Two	28,938		13,589
Year Three	19,910		27,175
Year Four	26,414		25,504
Year Five	24,782		3,533
Prior	12,545		10,429
Term Total	113,731		108,887
Revolving	86,270		116,406
Total	200,001		225,293
Pass | Closed end first mortgage loans | Consumer 1-4 Family Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	5,928		9,910
Year Two	10,099		10,541
Year Three	10,300		12,486
Year Four	12,237		8,614
Year Five	7,113		3,924
Prior	7,967		4,625
Term Total	53,644		50,100
Revolving	6,473		8,330
Total	60,117		58,430
Pass | Open end and junior lien loans | Consumer 1-4 Family Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		557
Year Two	775		137
Year Three	0		491
Year Four	478		335
Year Five	327		0
Prior	6		6
Term Total	1,586		1,526
Revolving	9,349		8,689
Total	10,935		10,215
Pass | Other consumer loans | Consumer 1-4 Family Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	1,121		1,082
Year Two	994		789
Year Three	769		1,391
Year Four	1,277		301
Year Five	275		0
Prior	0		0
Term Total	4,436		3,563
Revolving	12,221		11,894
Total	16,657		15,457
Special Mention | Other commercial loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		0
Year Three	0		0
Year Four	0		0
Year Five	0		0
Prior	2,230		2,419
Term Total	2,230		2,419
Revolving	0		0
Total	2,230		2,419
Special Mention | Working capital lines of credit loans | Commercial and industrial loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		0
Year Three	0		0
Year Four	0		0
Year Five	0		0
Prior	0		0
Term Total	0		0
Revolving	44,314		46,498
Total	44,314		46,498
Special Mention | Non-working capital loans | Commercial and industrial loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	586		4,038
Year Two	3,077		9,577
Year Three	10,126		1,051
Year Four	955		2,498
Year Five	1,293		2,306
Prior	4,593		4,298
Term Total	20,630		23,768
Revolving	4,317		5,477
Total	24,947		29,245
Special Mention | Owner occupied loans | Commercial Real Estate and Multifamily Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		7,597
Year Two	7,510		686
Year Three	15,265		4,913
Year Four	4,867		0
Year Five	0		1,394
Prior	3,582		2,245
Term Total	31,224		16,835
Revolving	0		14,739
Total	31,224		31,574
Special Mention | Nonowner occupied loans | Commercial Real Estate and Multifamily Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	586		4,503
Year Two	4,453		0
Year Three	0		6,257
Year Four	6,161		0
Year Five	0		0
Prior	2,223		2,246
Term Total	13,423		13,006
Revolving	0		0
Total	13,423		13,006
Special Mention | Multifamily loans | Commercial Real Estate and Multifamily Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	30,588		19,671
Year Two	0		0
Year Three	0		0
Year Four	0		0
Year Five	0		0
Prior	0		0
Term Total	30,588		19,671
Revolving	0		0
Total	30,588		19,671
Special Mention | Loans for agricultural production | Agri-business and agricultural loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		0
Year Three	0		187
Year Four	182		0
Year Five	0		0
Prior	0		0
Term Total	182		187
Revolving	500		500
Total	682		687
Special Mention | Closed end first mortgage loans | Consumer 1-4 Family Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		0
Year Three	0		0
Year Four	0		519
Year Five	510		0
Prior	0		0
Term Total	510		519
Revolving	0		0
Total	510		519
Substandard | Working capital lines of credit loans | Commercial and industrial loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		200
Year Three	0		0
Year Four	0		0
Year Five	0		125
Prior	125		0
Term Total	125		325
Revolving	17,956		20,516
Total	18,081		20,841
Substandard | Non-working capital loans | Commercial and industrial loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		3,754
Year Two	3,674		1,612
Year Three	1,604		683
Year Four	674		3,892
Year Five	3,681		51
Prior	270		218
Term Total	9,903		10,210
Revolving	396		397
Total	10,299		10,607
Substandard | Owner occupied loans | Commercial Real Estate and Multifamily Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		362
Year Two	351		250
Year Three	236		3,325
Year Four	2,134		1,474
Year Five	1,471		345
Prior	1,499		1,161
Term Total	5,691		6,917
Revolving	0		0
Total	5,691		6,917
Substandard | Loans secured by farmland | Agri-business and agricultural loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		0
Year Two	0		0
Year Three	0		0
Year Four	0		0
Year Five	0		0
Prior	96		100
Term Total	96		100
Revolving	0		0
Total	96		100
Substandard | Loans for agricultural production | Agri-business and agricultural loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0
Year Two	0
Year Three	0
Year Four	0
Year Five	0
Prior	0
Term Total	0
Revolving	0
Total	0
Substandard | Closed end first mortgage loans | Consumer 1-4 Family Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		87
Year Two	87		0
Year Three	0		96
Year Four	93		123
Year Five	123		0
Prior	228		253
Term Total	531		559
Revolving	0		0
Total	531		559
Substandard | Open end and junior lien loans | Consumer 1-4 Family Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		108
Year Two	107		0
Year Three	21		23
Year Four	21		0
Year Five	0		26
Prior	131		48
Term Total	280		205
Revolving	100		68
Total	380		273
Substandard | Other consumer loans | Consumer 1-4 Family Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0		40
Year Two	190		34
Year Three	33		35
Year Four	34		0
Year Five	0		2
Prior	0		0
Term Total	257		111
Revolving	0		0
Total	257		111
Doubtful | Loans for agricultural production | Agri-business and agricultural loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0
Year Two	0
Year Three	0
Year Four	0
Year Five	0
Prior	0
Term Total	0
Revolving	0
Total	0
Not Rated | Non-working capital loans | Commercial and industrial loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	273		2,585
Year Two	2,481		1,999
Year Three	1,773		881
Year Four	729		707
Year Five	611		162
Prior	136		18
Term Total	6,003		6,352
Revolving	0		0
Total	6,003		6,352
Not Rated | Loans for agricultural production | Agri-business and agricultural loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0
Year Two	0
Year Three	0
Year Four	0
Year Five	0
Prior	0
Term Total	0
Revolving	0
Total	0
Not Rated | Closed end first mortgage loans | Consumer 1-4 Family Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	3,871		64,233
Year Two	64,742		51,018
Year Three	49,563		38,014
Year Four	37,397		17,432
Year Five	16,804		4,314
Prior	26,741		23,225
Term Total	199,118		198,236
Revolving	0		0
Total	199,118		198,236
Not Rated | Open end and junior lien loans | Consumer 1-4 Family Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	5,616		24,792
Year Two	22,446		29,648
Year Three	26,928		8,471
Year Four	7,466		1,554
Year Five	1,288		2,286
Prior	3,793		1,962
Term Total	67,537		68,713
Revolving	112,000		112,371
Total	179,537		181,084
Not Rated | Residential construction loans: | Consumer 1-4 Family Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	681		1,525
Year Two	2,712		2,982
Year Three	3,726		1,515
Year Four	1,473		839
Year Five	819		263
Prior	1,465		1,220
Term Total	10,876		8,344
Revolving	0		0
Total	10,876		8,344
Not Rated | Other consumer loans | Consumer 1-4 Family Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	6,607		32,481
Year Two	30,095		17,585
Year Three	15,759		9,994
Year Four	9,109		6,008
Year Five	5,352		1,611
Prior	2,952		1,957
Term Total	69,874		69,636
Revolving	10,305		10,545
Total	$ 80,179		$ 80,181