ALLOWANCE FOR CREDIT LOSSES (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	$ 97,350	$ 62,639	$ 70,395	$ 61,963
Charge-offs	(3,564)	(4,780)	(9,865)	(6,730)
Recoveries	1,144	1,073	2,464	2,064
Provision	25,007	4,918	48,316	6,553
Provision			44,872	6,553
Ending Balance	119,937	63,850	119,937	63,850
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Balance at December 31, 2019	15,468		248
Impact of ASU 2016-13 adoption	17,392		17,392
Provision	1,924		3,540
Balance at June 30, 2020	17,392		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]
Balance at December 31, 2019			13,604
Impact of ASU 2016-13 adoption			13,604
Agricultural and Agricultural Real Estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	4,797	5,518	5,673	4,914
Charge-offs	(1)	(48)	(254)	(427)
Recoveries	0	1	826	329
Provision	905	515
Provision			(164)	1,170
Ending Balance	5,701	5,986	5,701	5,986
Agricultural and Agricultural Real Estate \| Impact of ASU 2016-13 adoption
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance			(380)
Residential Real Estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	8,725	1,623	1,504	1,813
Charge-offs	(235)	(201)	(314)	(341)
Recoveries	92	34	95	86
Provision	722	136
Provision			3,202	34
Ending Balance	9,304	1,592	9,304	1,592
Residential Real Estate \| Impact of ASU 2016-13 adoption
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance			4,817
Consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	9,757	4,798	4,816	5,296
Charge-offs	(245)	(446)	(597)	(820)
Recoveries	211	574	344	744
Provision	447	(8)
Provision			1,292	(302)
Ending Balance	10,170	4,918	10,170	4,918
Consumer \| Impact of ASU 2016-13 adoption
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance			4,315
Commercial and Industrial \| Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	32,463	27,250	30,787	26,306
Charge-offs	(2,767)	(3,971)	(8,363)	(4,951)
Recoveries	432	276	784	584
Provision	2,403	4,125
Provision			6,176	5,741
Ending Balance	32,531	27,680	32,531	27,680
Commercial and Industrial \| Commercial and industrial \| Impact of ASU 2016-13 adoption
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance			3,147
Paycheck Protection Program ("PPP") \| Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	0		0
Charge-offs	0		0
Recoveries	0		0
Provision	0
Provision			0
Ending Balance	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
Owner occupied commercial real estate \| Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	10,336	6,330	8,214	6,525
Charge-offs	(213)	(13)	(213)	(36)
Recoveries	191	4	192	93
Provision	13,088	(139)
Provision			15,616	(400)
Ending Balance	23,402	6,182	23,402	6,182
Owner occupied commercial real estate \| Commercial and industrial \| Impact of ASU 2016-13 adoption
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance			(407)
Non-owner occupied commercial real estate \| Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	8,321	7,126	7,802	7,430
Charge-offs	(19)	0	(19)	0
Recoveries	8	60	8	100
Provision	1,852	296
Provision			5,205	(48)
Ending Balance	10,162	7,482	10,162	7,482
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			(2,834)
Real Estate Construction \| Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	22,951	9,994	11,599	9,679
Charge-offs	(84)	(101)	(105)	(155)
Recoveries	210	124	215	128
Provision	5,590	(7)
Provision			13,545	358
Ending Balance	$ 28,667	$ 10,010	28,667	$ 10,010
Real Estate Construction \| Commercial and industrial \| Impact of ASU 2016-13 adoption
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance			$ 3,413

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 recovery of financing receivables doubtful of collection that were previously charged off.

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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 expense related to estimated loss from loan and lease transactions.

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