LOANS (Loans held to maturity) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Loans and Leases Receivable Disclosure [Line Items]
Gross Loans Receivable Held to Maturity	$ 11,495,353	$ 11,428,352
Allowance for credit losses	(112,707)	(109,483)	$ (100,522)	$ (110,088)
Loans receivable, net	11,382,646	11,318,869
Commercial and industrial \| Commercial and industrial
Loans and Leases Receivable Disclosure [Line Items]
Gross Loans Receivable Held to Maturity	3,498,345	3,464,414
Allowance for credit losses	(31,823)	(29,071)	(25,800)	(27,738)
Commercial and industrial \| Paycheck Protection Program ("PPP")
Loans and Leases Receivable Disclosure [Line Items]
Gross Loans Receivable Held to Maturity	8,258	11,025
Allowance for credit losses	0	0
Commercial and industrial \| Owner occupied commercial real estate
Loans and Leases Receivable Disclosure [Line Items]
Gross Loans Receivable Held to Maturity	2,312,538	2,265,307
Allowance for credit losses	(14,151)	(13,948)	(17,975)	(19,214)
Commercial and industrial \| Non-owner occupied commercial real estate
Loans and Leases Receivable Disclosure [Line Items]
Gross Loans Receivable Held to Maturity	2,421,341	2,330,940
Allowance for credit losses	(17,062)	(16,539)	(16,013)	(17,908)
Commercial and industrial \| Real Estate Construction
Loans and Leases Receivable Disclosure [Line Items]
Gross Loans Receivable Held to Maturity	1,102,186	1,076,082
Allowance for credit losses	(30,138)	(29,998)	(21,397)	(22,538)
Agricultural and agricultural real estate
Loans and Leases Receivable Disclosure [Line Items]
Gross Loans Receivable Held to Maturity	810,183	920,510
Allowance for credit losses	(2,546)	(2,634)	(2,667)	(5,213)
Residential real estate
Loans and Leases Receivable Disclosure [Line Items]
Gross Loans Receivable Held to Maturity	841,084	853,361
Allowance for credit losses	(7,564)	(7,711)	(7,875)	(8,427)
Consumer
Loans and Leases Receivable Disclosure [Line Items]
Gross Loans Receivable Held to Maturity	501,418	506,713
Allowance for credit losses	$ (9,423)	$ (9,582)	$ (8,795)	$ (9,050)

Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

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Amortized cost excluding accrued interest, before allowance for credit loss, fee, and loan in process, of financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=6378536&loc=d3e10095-111533

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(7))
-URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878

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