ALLOWANCE FOR CREDIT LOSSES (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	$ 120,726	$ 119,937	$ 131,606	$ 70,395
Charge-offs	(1,167)	(21,753)	(6,790)	(31,618)
Recoveries	2,422	452	3,615	2,916
Provision (benefit)	(4,448)	4,741	(10,898)	49,613
Ending Balance	117,533	103,377	117,533	103,377
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	14,002	17,392	15,280	248
Provision (benefit)	(35)	(3,062)	(1,313)	478
Ending balance	13,967	14,330	13,967	14,330
Impact of ASU 2016-13 adoption
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				12,071
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance			0	13,604
Adjusted balance at January 1, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				82,466
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance			15,280	13,852
Agricultural and Agricultural Real Estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	7,160	5,701	7,129	5,680
Charge-offs	(195)	(936)	(870)	(1,190)
Recoveries	466	1	487	827
Provision (benefit)	(1,105)	576	(420)	412
Ending Balance	6,326	5,342	6,326	5,342
Agricultural and Agricultural Real Estate \| Impact of ASU 2016-13 adoption
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				(387)
Agricultural and Agricultural Real Estate \| Adjusted balance at January 1, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				5,293
Residential Real Estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	9,741	9,304	11,935	1,504
Charge-offs	(22)	(54)	(113)	(368)
Recoveries	2	2	7	97
Provision (benefit)	(483)	419	(2,591)	3,621
Ending Balance	9,238	9,671	9,238	9,671
Residential Real Estate \| Impact of ASU 2016-13 adoption
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				4,817
Residential Real Estate \| Adjusted balance at January 1, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				6,321
Consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	10,095	10,184	12,770	4,822
Charge-offs	(725)	(522)	(2,032)	(1,715)
Recoveries	333	153	826	671
Provision (benefit)	(583)	(175)	(2,444)	1,553
Ending Balance	9,120	9,640	9,120	9,640
Consumer \| Impact of ASU 2016-13 adoption
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				4,309
Consumer \| Adjusted balance at January 1, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				9,131
Commercial and Industrial \| Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	31,332	32,518	38,818	34,207
Charge-offs	(106)	(6,888)	(1,896)	(14,655)
Recoveries	1,553	283	2,111	893
Provision (benefit)	(4,871)	8,668	(11,125)	14,408
Ending Balance	27,908	34,581	27,908	34,581
Commercial and Industrial \| Commercial and industrial \| Impact of ASU 2016-13 adoption
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				(272)
Commercial and Industrial \| Commercial and industrial \| Adjusted balance at January 1, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				33,935
Paycheck Protection Program ("PPP") \| Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	0	0	0	0
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision (benefit)	0	0	0	0
Ending Balance	0	0	0	0
Paycheck Protection Program ("PPP") \| Commercial and industrial \| Impact of ASU 2016-13 adoption
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				0
Paycheck Protection Program ("PPP") \| Commercial and industrial \| Adjusted balance at January 1, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				0
Owner occupied commercial real estate \| Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	19,990	23,402	20,001	7,921
Charge-offs	(119)	(13,328)	(232)	(13,541)
Recoveries	46	1	143	193
Provision (benefit)	(789)	1,154	(784)	16,770
Ending Balance	19,128	11,229	19,128	11,229
Owner occupied commercial real estate \| Commercial and industrial \| Impact of ASU 2016-13 adoption
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				(114)
Owner occupied commercial real estate \| Commercial and industrial \| Adjusted balance at January 1, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				7,807
Non-owner occupied commercial real estate \| Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	22,828	10,161	20,873	7,584
Charge-offs	0	(25)	(1,637)	(44)
Recoveries	20	10	33	18
Provision (benefit)	(733)	1,981	2,846	7,186
Ending Balance	22,115	12,127	22,115	12,127
Non-owner occupied commercial real estate \| Commercial and industrial \| Impact of ASU 2016-13 adoption
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				(2,617)
Non-owner occupied commercial real estate \| Commercial and industrial \| Adjusted balance at January 1, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				4,967
Real Estate Construction \| Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	19,580	28,667	20,080	8,677
Charge-offs	0	0	(10)	(105)
Recoveries	2	2	8	217
Provision (benefit)	4,116	(7,882)	3,620	5,663
Ending Balance	$ 23,698	$ 20,787	$ 23,698	20,787
Real Estate Construction \| Commercial and industrial \| Impact of ASU 2016-13 adoption
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				6,335
Real Estate Construction \| Commercial and industrial \| Adjusted balance at January 1, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				$ 15,012

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Amount of increase in allowance for credit loss on financing receivable from recovery.

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Amount of writeoff of financing receivable, charged against allowance for credit loss.

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Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

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Amount of expense (reversal of expense) for expected credit loss for off-balance sheet credit exposure. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

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