ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY OF FINANCING RECEIVABLES - Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Recorded Investment
Total	$ 21,673		$ 20,704
Unpaid Principal Balance
Total	22,924		21,883
Related Allowance	748		515
Average Recorded Investment
With no related allowance recorded	19,348	$ 6,387
With an allowance recorded	2,043	1,040
Total	21,391	7,427
Interest Income Recognized
With no related allowance recorded	142	23
With an allowance recorded	10	0
Total	152	23
Commercial and Industrial
Recorded Investment
With no related allowance recorded	77		0
With an allowance recorded	379		372
Total	456		372
Unpaid Principal Balance
With no related allowance recorded	180		10
With an allowance recorded	424		572
Total	604		582
Related Allowance	104		152
Average Recorded Investment
With no related allowance recorded	79	10
With an allowance recorded	335	0
Interest Income Recognized
With no related allowance recorded	0	0
With an allowance recorded	5	0
Construction
Average Recorded Investment
With no related allowance recorded	0	53
Interest Income Recognized
With no related allowance recorded	0	0
Commercial Real Estate
Recorded Investment
With no related allowance recorded	15,734		13,745
With an allowance recorded	932		2,015
Total	16,666		15,760
Unpaid Principal Balance
With no related allowance recorded	16,283		13,745
With an allowance recorded	1,145		2,437
Total	17,428		16,182
Related Allowance	445		274
Average Recorded Investment
With no related allowance recorded	15,469	3,871
With an allowance recorded	936	930
Interest Income Recognized
With no related allowance recorded	124	12
With an allowance recorded	5	0
Residential Real Estate
Recorded Investment
With no related allowance recorded	3,812		2,790
With an allowance recorded	739		1,782
Total	4,551		4,572
Unpaid Principal Balance
With no related allowance recorded	4,087		2,790
With an allowance recorded	805		2,329
Total	4,892		5,119
Related Allowance	199		$ 89
Average Recorded Investment
With no related allowance recorded	3,800	2,453
With an allowance recorded	772	110
Interest Income Recognized
With no related allowance recorded	18	11
With an allowance recorded	$ 0	$ 0