RECENTLY ADOPTED AND ISSUED ACCOUNTING STANDARDS (Details) - USD ($) $ in Thousands		6 Months Ended
	Jan. 01, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Allowance	$ 119,155	$ 158,661	$ 143,885	$ 57,650	$ 61,549	$ 56,722	$ 56,542
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	61,505	61,505
Deferred Tax Liabilities, Deferred Expense	16,252			33,030
Deferred tax liability, Credit Loss, Change in Method, Credit Loss Expense (Reversal)	(16,778)
Off-Balance Sheet, Credit Loss, Liability	12,740			585
Off-Balance Sheet, Credit Loss, Liability, Change in Method, Credit Loss Expense (Reversal)	12,155
Commercial
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Allowance	28,485	50,421	45,410	18,584	24,586	19,926	18,746
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	9,901	9,901
Lease financing
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Allowance	1,089	1,431	1,494	971	1,393	1,373	1,130
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	118	118
Construction real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Allowance	13,960	15,357	13,511	2,381	2,919	2,793	3,413
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	11,579	11,579
Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Allowance	47,697	62,340	53,154	23,579	20,357	20,400	21,048
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	24,118	24,118
Residential real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Allowance	10,789	10,581	11,284	5,299	5,008	5,043	4,964
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	5,490	5,490
Home equity
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Allowance	13,217	14,236	14,827	4,787	5,307	5,250	5,348
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	8,430	8,430
Installment
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Allowance	1,193	1,226	1,238	392	395	380	362
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	801	801
Credit card
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Allowance	2,725	3,069	$ 2,967	$ 1,657	$ 1,584	$ 1,557	$ 1,531
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	$ 1,068	$ 1,068