ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY INFORMATION - Schedule of Loans Identified as Troubled Debt Restructurings During Periods Indicated (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total loans identified during the period	$ 997	$ 1,253
Residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total loans identified during the period	167	226
Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total loans identified during the period	830	247
Commercial and industrial | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total loans identified during the period	0	20
Owner-occupied commercial | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total loans identified during the period	0	650
Commercial mortgages | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total loans identified during the period	$ 0	$ 110