LOANS (Allowance for credit losses on financing receivables) (Details) - USD ($)	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans individually evaluated for impairment, nonaccrual threshold	$ 500,000
Allowance For Credit Losses
Individually Evaluated for Credit Losses	9,933,000		$ 20,413,000
Collectively Evaluated for Credit Losses	96,864,000		102,153,000
Total	106,797,000	$ 126,861,000	122,566,000	$ 110,208,000	$ 111,198,000	$ 109,483,000
Gross Loans Receivable Held to Maturity
Loans Individually Evaluated for Credit Losses	50,797,000		80,385,000
Loans Collectively Evaluated for Credit Losses	11,390,120,000		11,988,260,000
Total	11,440,917,000		12,068,645,000
Paycheck Protection Program ("PPP")
Allowance For Credit Losses
Total	0
Commercial and industrial | Commercial and industrial
Allowance For Credit Losses
Individually Evaluated for Credit Losses	3,185,000		18,425,000
Collectively Evaluated for Credit Losses	20,234,000		22,254,000
Total	23,419,000	44,800,000	40,679,000	28,296,000	29,396,000	29,071,000
Gross Loans Receivable Held to Maturity
Loans Individually Evaluated for Credit Losses	18,428,000		41,847,000
Loans Collectively Evaluated for Credit Losses	3,484,665,000		3,610,200,000
Total	3,503,093,000		3,652,047,000
Commercial and industrial | Paycheck Protection Program ("PPP")
Allowance For Credit Losses
Individually Evaluated for Credit Losses	0		0
Collectively Evaluated for Credit Losses	0		0
Total	0		0
Gross Loans Receivable Held to Maturity
Loans Individually Evaluated for Credit Losses	0		0
Loans Collectively Evaluated for Credit Losses	1,582,000		2,777,000
Total	1,582,000		2,777,000
Commercial and industrial | Owner occupied commercial real estate
Allowance For Credit Losses
Individually Evaluated for Credit Losses	2,000		0
Collectively Evaluated for Credit Losses	13,249,000		17,156,000
Total	13,251,000	14,714,000	17,156,000	14,674,000	14,709,000	13,948,000
Gross Loans Receivable Held to Maturity
Loans Individually Evaluated for Credit Losses	2,633,000		30,400,000
Loans Collectively Evaluated for Credit Losses	2,487,064,000		2,607,775,000
Total	2,489,697,000		2,638,175,000
Commercial and industrial | Non-owner occupied commercial real estate
Allowance For Credit Losses
Individually Evaluated for Credit Losses	4,447,000		0
Collectively Evaluated for Credit Losses	12,972,000		17,249,000
Total	17,419,000	13,697,000	17,249,000	17,284,000	17,976,000	16,539,000
Gross Loans Receivable Held to Maturity
Loans Individually Evaluated for Credit Losses	10,108,000		0
Loans Collectively Evaluated for Credit Losses	2,445,288,000		2,553,711,000
Total	2,455,396,000		2,553,711,000
Commercial and industrial | Real estate construction
Allowance For Credit Losses
Individually Evaluated for Credit Losses	22,000		56,000
Collectively Evaluated for Credit Losses	35,458,000		28,717,000
Total	35,480,000	32,210,000	28,773,000	28,979,000	28,246,000	29,998,000
Gross Loans Receivable Held to Maturity
Loans Individually Evaluated for Credit Losses	697,000		697,000
Loans Collectively Evaluated for Credit Losses	1,119,225,000		1,011,019,000
Total	1,119,922,000		1,011,716,000
Agricultural and agricultural real estate
Allowance For Credit Losses
Individually Evaluated for Credit Losses	2,277,000		1,932,000
Collectively Evaluated for Credit Losses	1,526,000		2,360,000
Total	3,803,000	8,905,000	4,292,000	4,404,000	3,511,000	2,634,000
Gross Loans Receivable Held to Maturity
Loans Individually Evaluated for Credit Losses	18,204,000		6,700,000
Loans Collectively Evaluated for Credit Losses	683,007,000		912,484,000
Total	701,211,000		919,184,000
Residential real estate
Allowance For Credit Losses
Individually Evaluated for Credit Losses	0		0
Collectively Evaluated for Credit Losses	5,355,000		5,845,000
Total	5,355,000	5,036,000	5,845,000	7,107,000	7,644,000	7,711,000
Gross Loans Receivable Held to Maturity
Loans Individually Evaluated for Credit Losses	727,000		741,000
Loans Collectively Evaluated for Credit Losses	707,257,000		797,088,000
Total	707,984,000		797,829,000
Consumer
Allowance For Credit Losses
Individually Evaluated for Credit Losses	0		0
Collectively Evaluated for Credit Losses	8,070,000		8,572,000
Total	8,070,000	$ 7,499,000	8,572,000	$ 9,464,000	$ 9,716,000	$ 9,582,000
Gross Loans Receivable Held to Maturity
Loans Individually Evaluated for Credit Losses	0		0
Loans Collectively Evaluated for Credit Losses	462,032,000		493,206,000
Total	$ 462,032,000		$ 493,206,000