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		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Financing Receivable, Modifications [Line Items]
Total loans identified during the period	$ 7,676	$ 1,136	$ 9,316	$ 7,188
Commercial
Financing Receivable, Modifications [Line Items]
Total loans identified during the period	4,782	338	4,782	781
Commercial mortgages
Financing Receivable, Modifications [Line Items]
Total loans identified during the period	1,564	0	2,022	0
Construction
Financing Receivable, Modifications [Line Items]
Total loans identified during the period	0	124	920	1,836
Residential
Financing Receivable, Modifications [Line Items]
Total loans identified during the period	469	0	469	242
Consumer
Financing Receivable, Modifications [Line Items]
Total loans identified during the period	861	674	1,123	1,258
Owner-occupied commercial
Financing Receivable, Modifications [Line Items]
Total loans identified during the period	$ 0	$ 0	$ 0	$ 3,071