ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY INFORMATION - Schedule of Types of TDR (Details) - loan	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total	21	10
Commercial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total		1
Commercial | Owner-occupied commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total		1
Commercial | Commercial mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total		1
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total	2	2
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total	19	5
Contractual payment reduction and term extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total	0	2
Contractual payment reduction and term extension | Commercial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total		1
Contractual payment reduction and term extension | Commercial | Owner-occupied commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total		1
Contractual payment reduction and term extension | Commercial | Commercial mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total		0
Contractual payment reduction and term extension | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total	0	0
Contractual payment reduction and term extension | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total	0	0
Maturity Date Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total	0	1
Maturity Date Extension | Commercial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total		0
Maturity Date Extension | Commercial | Owner-occupied commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total		0
Maturity Date Extension | Commercial | Commercial mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total		1
Maturity Date Extension | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total	0	0
Maturity Date Extension | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total	0	0
Discharged in bankruptcy
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total	21	4
Discharged in bankruptcy | Commercial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total		0
Discharged in bankruptcy | Commercial | Owner-occupied commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total		0
Discharged in bankruptcy | Commercial | Commercial mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total		0
Discharged in bankruptcy | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total	2	1
Discharged in bankruptcy | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total	19	3
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total	0	3
Other | Commercial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total		0
Other | Commercial | Owner-occupied commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total		0
Other | Commercial | Commercial mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total		0
Other | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total	0	1
Other | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Modification Total	0	2