LOANS (Loans by credit quality indicator) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	$ 987,450	$ 3,398,505
Year Two	3,149,124	1,480,531
Year Three	1,310,100	1,234,564
Year Four	1,076,315	751,481
Year Five	656,339	586,363
Year Six and Prior	1,571,395	1,134,111
Revolving	1,426,662	1,369,017
Total	10,177,385	9,954,572
Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	973,039	3,279,966
Year Two	3,060,060	1,391,907
Year Three	1,238,272	1,116,618
Year Four	980,595	617,337
Year Five	537,791	522,707
Year Six and Prior	1,384,801	978,672
Revolving	1,357,311	1,306,109
Total	9,531,869	9,213,316
Watch
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	4,707	41,994
Year Two	30,729	49,038
Year Three	45,891	63,780
Year Four	45,926	96,879
Year Five	83,388	24,388
Year Six and Prior	66,609	62,313
Revolving	33,334	30,833
Total	310,584	369,225
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	9,704	76,545
Year Two	58,335	39,586
Year Three	25,937	54,166
Year Four	49,794	37,265
Year Five	35,160	39,268
Year Six and Prior	119,985	93,126
Revolving	36,017	32,075
Total	334,932	372,031
Commercial and industrial | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	285,970	635,180
Year Two	590,952	378,714
Year Three	337,509	229,560
Year Four	164,507	106,439
Year Five	96,834	181,939
Year Six and Prior	510,349	357,122
Revolving	828,392	756,131
Total	2,814,513	2,645,085
Commercial and industrial | Commercial and industrial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	282,325	604,659
Year Two	563,865	359,533
Year Three	321,463	203,960
Year Four	142,201	89,694
Year Five	82,846	171,709
Year Six and Prior	490,118	330,094
Revolving	771,746	708,525
Total	2,654,564	2,468,174
Commercial and industrial | Commercial and industrial | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	1,133	10,633
Year Two	12,201	12,790
Year Three	10,346	12,550
Year Four	9,644	8,210
Year Five	6,049	3,611
Year Six and Prior	3,309	14,976
Revolving	28,376	24,626
Total	71,058	87,396
Commercial and industrial | Commercial and industrial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	2,512	19,888
Year Two	14,886	6,391
Year Three	5,700	13,050
Year Four	12,662	8,535
Year Five	7,939	6,619
Year Six and Prior	16,922	12,052
Revolving	28,270	22,980
Total	88,891	89,515
Commercial and industrial | Paycheck Protection Program ("PPP")
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0	174,028
Year Two	69,552	25,855
Year Three	4,513	0
Year Four	0	0
Year Five	0	0
Year Six and Prior	0	0
Revolving	0	0
Total	74,065	199,883
Commercial and industrial | Paycheck Protection Program ("PPP") | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0	146,370
Year Two	60,429	25,707
Year Three	4,463	0
Year Four	0	0
Year Five	0	0
Year Six and Prior	0	0
Revolving	0	0
Total	64,892	172,077
Commercial and industrial | Paycheck Protection Program ("PPP") | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0	10,726
Year Two	1,797	127
Year Three	31	0
Year Four	0	0
Year Five	0	0
Year Six and Prior	0	0
Revolving	0	0
Total	1,828	10,853
Commercial and industrial | Paycheck Protection Program ("PPP") | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0	16,932
Year Two	7,326	21
Year Three	19	0
Year Four	0	0
Year Five	0	0
Year Six and Prior	0	0
Revolving	0	0
Total	7,345	16,953
Commercial and industrial | Owner occupied commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	192,350	956,677
Year Two	913,990	362,777
Year Three	339,427	336,990
Year Four	324,952	194,246
Year Five	160,602	144,086
Year Six and Prior	312,670	209,540
Revolving	22,085	36,018
Total	2,266,076	2,240,334
Commercial and industrial | Owner occupied commercial real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	186,033	940,043
Year Two	896,361	328,052
Year Three	312,517	315,497
Year Four	306,341	180,936
Year Five	148,493	115,142
Year Six and Prior	275,086	189,647
Revolving	20,300	34,233
Total	2,145,131	2,103,550
Commercial and industrial | Owner occupied commercial real estate | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	2,944	4,676
Year Two	6,266	13,956
Year Three	17,523	7,759
Year Four	6,524	10,501
Year Five	8,556	15,032
Year Six and Prior	10,802	6,830
Revolving	35	35
Total	52,650	58,789
Commercial and industrial | Owner occupied commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	3,373	11,958
Year Two	11,363	20,769
Year Three	9,387	13,734
Year Four	12,087	2,809
Year Five	3,553	13,912
Year Six and Prior	26,782	13,063
Revolving	1,750	1,750
Total	68,295	77,995
Commercial and industrial | Non-owner occupied commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	241,624	630,444
Year Two	617,569	282,814
Year Three	277,339	373,109
Year Four	377,393	269,649
Year Five	233,444	170,947
Year Six and Prior	383,278	254,459
Revolving	31,114	29,169
Total	2,161,761	2,010,591
Commercial and industrial | Non-owner occupied commercial real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	238,611	609,968
Year Two	602,044	263,093
Year Three	257,093	315,815
Year Four	330,145	236,823
Year Five	211,111	152,059
Year Six and Prior	286,939	166,792
Revolving	31,114	28,728
Total	1,957,057	1,773,278
Commercial and industrial | Non-owner occupied commercial real estate | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	206	4,754
Year Two	2,757	9,109
Year Three	11,098	35,496
Year Four	26,639	29,227
Year Five	20,512	4,865
Year Six and Prior	38,483	35,901
Revolving	0	0
Total	99,695	119,352
Commercial and industrial | Non-owner occupied commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	2,807	15,722
Year Two	12,768	10,612
Year Three	9,148	21,798
Year Four	20,609	3,599
Year Five	1,821	14,023
Year Six and Prior	57,856	51,766
Revolving	0	441
Total	105,009	117,961
Commercial and industrial | Real estate construction
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	117,525	383,987
Year Two	383,907	207,787
Year Three	150,497	171,797
Year Four	98,780	62,987
Year Five	63,602	7,163
Year Six and Prior	13,150	7,877
Revolving	15,022	14,521
Total	842,483	856,119
Commercial and industrial | Real estate construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	117,525	381,283
Year Two	378,301	206,879
Year Three	149,415	169,606
Year Four	98,294	14,197
Year Five	14,036	7,163
Year Six and Prior	9,362	7,823
Revolving	15,009	14,507
Total	781,942	801,458
Commercial and industrial | Real estate construction | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0	2,704
Year Two	3,058	858
Year Three	1,033	2,145
Year Four	0	44,846
Year Five	44,468	0
Year Six and Prior	3,697	0
Revolving	13	14
Total	52,269	50,567
Commercial and industrial | Real estate construction | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0	0
Year Two	2,548	50
Year Three	49	46
Year Four	486	3,944
Year Five	5,098	0
Year Six and Prior	91	54
Revolving	0	0
Total	8,272	4,094
Agricultural and agricultural real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	73,644	230,447
Year Two	206,240	113,515
Year Three	103,888	57,525
Year Four	51,347	51,008
Year Five	45,626	25,274
Year Six and Prior	61,184	46,445
Revolving	224,514	229,539
Total	766,443	753,753
Agricultural and agricultural real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	72,343	217,179
Year Two	195,360	102,030
Year Three	97,315	47,927
Year Four	45,549	32,913
Year Five	29,107	22,029
Year Six and Prior	49,812	35,548
Revolving	215,800	220,065
Total	705,286	677,691
Agricultural and agricultural real estate | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	421	4,018
Year Two	3,694	10,390
Year Three	5,630	4,688
Year Four	2,051	2,270
Year Five	2,002	33
Year Six and Prior	2,739	2,038
Revolving	3,126	2,948
Total	19,663	26,385
Agricultural and agricultural real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	880	9,250
Year Two	7,186	1,095
Year Three	943	4,910
Year Four	3,747	15,825
Year Five	14,517	3,212
Year Six and Prior	8,633	8,859
Revolving	5,588	6,526
Total	41,494	49,677
Residential real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	59,206	317,748
Year Two	306,446	88,298
Year Three	78,794	51,922
Year Four	47,544	57,542
Year Five	48,252	45,492
Year Six and Prior	261,544	238,264
Revolving	23,456	30,017
Total	825,242	829,283
Residential real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	59,105	311,292
Year Two	303,926	86,355
Year Three	78,252	50,762
Year Four	46,766	53,773
Year Five	44,833	43,619
Year Six and Prior	246,933	230,566
Revolving	23,456	29,017
Total	803,271	805,384
Residential real estate | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	0	3,928
Year Two	484	1,499
Year Three	157	750
Year Four	736	1,452
Year Five	1,435	734
Year Six and Prior	6,915	1,977
Revolving	0	1,000
Total	9,727	11,340
Residential real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	101	2,528
Year Two	2,036	444
Year Three	385	410
Year Four	42	2,317
Year Five	1,984	1,139
Year Six and Prior	7,696	5,721
Revolving	0	0
Total	12,244	12,559
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	17,131	69,994
Year Two	60,468	20,771
Year Three	18,133	13,661
Year Four	11,792	9,610
Year Five	7,979	11,462
Year Six and Prior	29,220	20,404
Revolving	282,079	273,622
Total	426,802	419,524
Consumer | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	17,097	69,172
Year Two	59,774	20,258
Year Three	17,754	13,051
Year Four	11,299	9,001
Year Five	7,365	10,986
Year Six and Prior	26,551	18,202
Revolving	279,886	271,034
Total	419,726	411,704
Consumer | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	3	555
Year Two	472	309
Year Three	73	392
Year Four	332	373
Year Five	366	113
Year Six and Prior	664	591
Revolving	1,784	2,210
Total	3,694	4,543
Consumer | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year One	31	267
Year Two	222	204
Year Three	306	218
Year Four	161	236
Year Five	248	363
Year Six and Prior	2,005	1,611
Revolving	409	378
Total	$ 3,382	$ 3,277