LOANS (Past due financing receivables) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Nonaccrual	$ 94,800	$ 95,426
Total Loans	11,644,641	12,068,645
Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	36,531	13,477
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	14,495	7,704
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	21,425	3,266
90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	611	2,507
Current
Financing Receivable, Past Due [Line Items]
Total Loans	11,513,310	11,959,742
Commercial and industrial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Nonaccrual	47,063	46,815
Total Loans	3,545,051	3,652,047
Commercial and industrial | Commercial and industrial | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	7,489	4,067
Commercial and industrial | Commercial and industrial | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	6,540	1,738
Commercial and industrial | Commercial and industrial | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	512	126
Commercial and industrial | Commercial and industrial | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	437	2,203
Commercial and industrial | Commercial and industrial | Current
Financing Receivable, Past Due [Line Items]
Total Loans	3,490,499	3,601,165
Commercial and industrial | Paycheck Protection Program ("PPP")
Financing Receivable, Past Due [Line Items]
Nonaccrual	0	0
Total Loans	2,172	2,777
Commercial and industrial | Paycheck Protection Program ("PPP") | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	147
Commercial and industrial | Paycheck Protection Program ("PPP") | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	94
Commercial and industrial | Paycheck Protection Program ("PPP") | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	53
Commercial and industrial | Paycheck Protection Program ("PPP") | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Commercial and industrial | Paycheck Protection Program ("PPP") | Current
Financing Receivable, Past Due [Line Items]
Total Loans	2,172	2,630
Commercial and industrial | Owner occupied commercial real estate
Financing Receivable, Past Due [Line Items]
Nonaccrual	31,117	31,592
Total Loans	2,545,033	2,638,175
Commercial and industrial | Owner occupied commercial real estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	2,043	2,943
Commercial and industrial | Owner occupied commercial real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	1,969	205
Commercial and industrial | Owner occupied commercial real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	74	2,664
Commercial and industrial | Owner occupied commercial real estate | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	74
Commercial and industrial | Owner occupied commercial real estate | Current
Financing Receivable, Past Due [Line Items]
Total Loans	2,511,873	2,603,640
Commercial and industrial | Non-owner occupied commercial real estate
Financing Receivable, Past Due [Line Items]
Nonaccrual	0	367
Total Loans	2,495,068	2,553,711
Commercial and industrial | Non-owner occupied commercial real estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	875
Commercial and industrial | Non-owner occupied commercial real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	875
Commercial and industrial | Non-owner occupied commercial real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Commercial and industrial | Non-owner occupied commercial real estate | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Commercial and industrial | Non-owner occupied commercial real estate | Current
Financing Receivable, Past Due [Line Items]
Total Loans	2,495,068	2,552,469
Commercial and industrial | Real estate construction
Financing Receivable, Past Due [Line Items]
Nonaccrual	903	783
Total Loans	1,041,583	1,011,716
Commercial and industrial | Real estate construction | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	23,899	332
Commercial and industrial | Real estate construction | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	3,931	332
Commercial and industrial | Real estate construction | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	19,968	0
Commercial and industrial | Real estate construction | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Commercial and industrial | Real estate construction | Current
Financing Receivable, Past Due [Line Items]
Total Loans	1,016,781	1,010,601
Agricultural and agricultural real estate
Financing Receivable, Past Due [Line Items]
Nonaccrual	9,444	9,210
Total Loans	809,876	919,184
Agricultural and agricultural real estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	394	133
Agricultural and agricultural real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	382	121
Agricultural and agricultural real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Agricultural and agricultural real estate | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	12	12
Agricultural and agricultural real estate | Current
Financing Receivable, Past Due [Line Items]
Total Loans	800,038	909,841
Residential real estate
Financing Receivable, Past Due [Line Items]
Nonaccrual	4,881	5,086
Total Loans	756,021	797,829
Residential real estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	974	2,376
Residential real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	818	2,082
Residential real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	53	273
Residential real estate | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	103	21
Residential real estate | Current
Financing Receivable, Past Due [Line Items]
Total Loans	750,166	790,367
Consumer
Financing Receivable, Past Due [Line Items]
Nonaccrual	1,392	1,573
Total Loans	449,837	493,206
Consumer | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	1,732	2,604
Consumer | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	855	2,257
Consumer | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	818	150
Consumer | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	59	197
Consumer | Current
Financing Receivable, Past Due [Line Items]
Total Loans	$ 446,713	$ 489,029