ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY INFORMATION - Schedule of Loans Identified as Troubled Debt Restructurings During Periods Indicated (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Financing Receivable, Modifications [Line Items]
Total loans identified during the period	$ 601	$ 1,667	$ 9,917	$ 8,855
Commercial
Financing Receivable, Modifications [Line Items]
Total loans identified during the period	320	0	5,102	781
Commercial mortgages
Financing Receivable, Modifications [Line Items]
Total loans identified during the period	168	0	2,190	0
Construction
Financing Receivable, Modifications [Line Items]
Total loans identified during the period	0	0	920	1,836
Residential
Financing Receivable, Modifications [Line Items]
Total loans identified during the period	0	1,058	469	1,300
Consumer
Financing Receivable, Modifications [Line Items]
Total loans identified during the period	113	609	1,236	1,867
Owner-occupied commercial
Financing Receivable, Modifications [Line Items]
Total loans identified during the period	$ 0	$ 0	$ 0	$ 3,071