ALLOWANCE FOR CREDIT LOSSES (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	$ 130,172	$ 97,350	$ 131,606	$ 70,395
Charge-offs	(3,497)	(3,564)	(5,623)	(9,865)
Recoveries	517	1,144	1,193	2,464
Provision	(6,466)	25,007	(6,450)	44,872
Ending Balance	120,726	119,937	120,726	119,937
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	14,619	15,468	15,280	248
Provision	(617)	1,924	(1,278)	3,540
Ending balance	14,002	17,392	14,002	17,392
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	7,111	4,797	7,129	5,680
Charge-offs	(357)	(1)	(675)	(254)
Recoveries	0	0	21	826
Provision	406	905	685	(164)
Ending Balance	7,160	5,701	7,160	5,701
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	11,012	8,725	11,935	1,504
Charge-offs	(70)	(235)	(91)	(314)
Recoveries	0	92	5	95
Provision	(1,201)	722	(2,108)	3,202
Ending Balance	9,741	9,304	9,741	9,304
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	11,913	9,765	12,770	4,822
Charge-offs	(509)	(476)	(1,307)	(1,193)
Recoveries	191	298	493	518
Provision	(1,500)	597	(1,861)	1,728
Ending Balance	10,095	10,184	10,095	10,184
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	36,095	32,455	38,818	34,207
Charge-offs	(842)	(2,536)	(1,790)	(7,767)
Recoveries	265	345	558	610
Provision	(4,186)	2,254	(6,254)	5,740
Ending Balance	31,332	32,518	31,332	32,518
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	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	19,416	10,337	20,001	7,921
Charge-offs	(72)	(213)	(113)	(213)
Recoveries	44	191	97	192
Provision	602	13,087	5	15,616
Ending Balance	19,990	23,402	19,990	23,402
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	24,694	8,320	20,873	7,584
Charge-offs	(1,637)	(19)	(1,637)	(19)
Recoveries	13	8	13	8
Provision	(242)	1,852	3,579	5,205
Ending Balance	22,828	10,161	22,828	10,161
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	19,931	22,951	20,080	8,677
Charge-offs	(10)	(84)	(10)	(105)
Recoveries	4	210	6	215
Provision	(345)	5,590	(496)	13,545
Ending Balance	$ 19,580	$ 28,667	$ 19,580	28,667
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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Amount of credit loss expense (reversal of expense) for financing receivable.

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