ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY OF FINANCING RECEIVABLES - Age Analysis Of Loans Receivable (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 18,024	$ 19,212
Current	1,668,408	1,610,900
Net loans receivable	1,686,432	1,630,112
Recorded Investment 90 Days and Accruing	0	0
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	4,653	7,203
60-89 days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	310	594
Greater Than 90 Days
Financing Receivable, Past Due [Line Items]
Total Past Due	13,061	11,415
Commercial and Industrial
Financing Receivable, Past Due [Line Items]
Total Past Due	212	1,006
Current	133,442	123,931
Net loans receivable	133,654	124,937
Recorded Investment 90 Days and Accruing	0	0
Commercial and Industrial | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	0	300
Commercial and Industrial | 60-89 days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	0	5
Commercial and Industrial | Greater Than 90 Days
Financing Receivable, Past Due [Line Items]
Total Past Due	212	701
Construction
Financing Receivable, Past Due [Line Items]
Total Past Due	85	0
Current	114,649	125,291
Net loans receivable	114,734	125,291
Recorded Investment 90 Days and Accruing	0	0
Construction | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	85	0
Construction | 60-89 days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	0	0
Construction | Greater Than 90 Days
Financing Receivable, Past Due [Line Items]
Total Past Due	0	0
Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Total Past Due	11,071	12,037
Current	1,045,674	983,183
Net loans receivable	1,056,745	995,220
Recorded Investment 90 Days and Accruing	0	0
Commercial Real Estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	3,669	6,326
Commercial Real Estate | 60-89 days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	65	68
Commercial Real Estate | Greater Than 90 Days
Financing Receivable, Past Due [Line Items]
Total Past Due	7,337	5,643
Residential Real Estate
Financing Receivable, Past Due [Line Items]
Total Past Due	6,408	6,153
Current	372,988	376,414
Net loans receivable	379,396	382,567
Recorded Investment 90 Days and Accruing	0	0
Residential Real Estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	859	563
Residential Real Estate | 60-89 days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	37	520
Residential Real Estate | Greater Than 90 Days
Financing Receivable, Past Due [Line Items]
Total Past Due	5,512	5,070
Consumer and Other
Financing Receivable, Past Due [Line Items]
Total Past Due	248	16
Current	1,655	2,081
Net loans receivable	1,903	2,097
Recorded Investment 90 Days and Accruing	0	0
Consumer and Other | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	40	14
Consumer and Other | 60-89 days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	208	1
Consumer and Other | Greater Than 90 Days
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 0	$ 1