LOANS (Past due financing receivables) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Financing Receivable, Past Due [Line Items]
Nonaccrual	$ 61,956	$ 58,231
Total Loans	11,717,974	11,428,352
Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	15,121	5,039
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	9,118	3,907
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	4,544	859
90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	1,459	273
Current
Financing Receivable, Past Due [Line Items]
Total Loans	11,640,897	11,365,082
Commercial and industrial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Nonaccrual	20,936	22,766
Total Loans	3,590,680	3,464,414
Commercial and industrial | Commercial and industrial | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	8,365	1,586
Commercial and industrial | Commercial and industrial | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	6,646	1,099
Commercial and industrial | Commercial and industrial | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	1,202	356
Commercial and industrial | Commercial and industrial | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	517	131
Commercial and industrial | Commercial and industrial | Current
Financing Receivable, Past Due [Line Items]
Total Loans	3,561,379	3,440,062
Commercial and industrial | Paycheck Protection Program ("PPP")
Financing Receivable, Past Due [Line Items]
Nonaccrual	0	19
Total Loans	4,139	11,025
Commercial and industrial | Paycheck Protection Program ("PPP") | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	128	0
Commercial and industrial | Paycheck Protection Program ("PPP") | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	19	0
Commercial and industrial | Paycheck Protection Program ("PPP") | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Commercial and industrial | Paycheck Protection Program ("PPP") | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	109	0
Commercial and industrial | Paycheck Protection Program ("PPP") | Current
Financing Receivable, Past Due [Line Items]
Total Loans	4,011	11,006
Commercial and industrial | Owner occupied commercial real estate
Financing Receivable, Past Due [Line Items]
Nonaccrual	8,340	8,803
Total Loans	2,398,698	2,265,307
Commercial and industrial | Owner occupied commercial real estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	2,427	139
Commercial and industrial | Owner occupied commercial real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	137	12
Commercial and industrial | Owner occupied commercial real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	2,290	127
Commercial and industrial | Owner occupied commercial real estate | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Commercial and industrial | Owner occupied commercial real estate | Current
Financing Receivable, Past Due [Line Items]
Total Loans	2,387,931	2,256,365
Commercial and industrial | Non-owner occupied commercial real estate
Financing Receivable, Past Due [Line Items]
Nonaccrual	14,221	11,658
Total Loans	2,530,736	2,330,940
Commercial and industrial | Non-owner occupied commercial real estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Commercial and industrial | Non-owner occupied commercial real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
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	2,516,515	2,319,282
Commercial and industrial | Real estate construction
Financing Receivable, Past Due [Line Items]
Nonaccrual	2,824	2,351
Total Loans	1,013,134	1,076,082
Commercial and industrial | Real estate construction | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	36	44
Commercial and industrial | Real estate construction | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	36	16
Commercial and industrial | Real estate construction | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	28
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	1,010,274	1,073,687
Agricultural and agricultural real estate
Financing Receivable, Past Due [Line Items]
Nonaccrual	9,534	6,232
Total Loans	839,817	920,510
Agricultural and agricultural real estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	469	190
Agricultural and agricultural real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	108	48
Agricultural and agricultural real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	360	0
Agricultural and agricultural real estate | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	1	142
Agricultural and agricultural real estate | Current
Financing Receivable, Past Due [Line Items]
Total Loans	829,814	914,088
Residential real estate
Financing Receivable, Past Due [Line Items]
Nonaccrual	4,738	5,264
Total Loans	828,437	853,361
Residential real estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	1,774	1,358
Residential real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	673	1,206
Residential real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	321	152
Residential real estate | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	780	0
Residential real estate | Current
Financing Receivable, Past Due [Line Items]
Total Loans	821,925	846,739
Consumer
Financing Receivable, Past Due [Line Items]
Nonaccrual	1,363	1,138
Total Loans	512,333	506,713
Consumer | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	1,922	1,722
Consumer | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	1,499	1,526
Consumer | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	371	196
Consumer | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	52	0
Consumer | Current
Financing Receivable, Past Due [Line Items]
Total Loans	$ 509,048	$ 503,853