LOANS AND ALLOWANCE FOR LOAN LOSSES (Summary of Impaired Loan Balances and Associated Allowance by Portfolio Segment) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	$ 3,227	$ 4,244	$ 3,227	$ 4,244	$ 4,476
Unpaid Principal Balance - with an allowance recorded	3,227	4,244	3,227	4,244	4,476
Related Allowance	738	756	738	756	824
Average Recorded Investment - with an allowance recorded	4,115	4,282	4,205	5,088	5,921
Interest Income Recognized - with an allowance recorded	31	33	93	113	138
Recorded Investment - without allowance recorded	2,290	7,868	2,290	7,868	2,450
Unpaid Principal Balance - without allowance recorded	3,414	9,682	3,414	9,682	3,001
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0	0	0
Average Recorded Investment - without allowance recorded	1,960	8,069	2,081	6,098	5,368
Interest Income Recognized - without allowance recorded	15	15	43	33	55
Impaired Financing Receivable, Recorded Investment	5,517	12,112	5,517	12,112	6,926
Impaired financing receivable, unpaid principal balance	6,641	13,926	6,641	13,926	7,477
Impaired Financing Receivable, Average Recorded Investment	6,075	12,351	6,286	11,186	11,289
Impaired Financing Receivable, Interest Income, Accrual Method	46	48	136	146	193
Residential Real Estate
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	2,337	3,577	2,337	3,577	3,471
Unpaid Principal Balance - with an allowance recorded	2,337	3,577	2,337	3,577	3,471
Related Allowance	337	619	337	619	586
Average Recorded Investment - with an allowance recorded	3,026	3,541	3,137	2,428	3,591
Interest Income Recognized - with an allowance recorded	28	27	84	96	127
Recorded Investment - without allowance recorded	1,543	1,607	1,543	1,607	1,291
Unpaid Principal Balance - without allowance recorded	2,007	1,807	2,007	1,807	1,415
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0	0	0
Average Recorded Investment - without allowance recorded	1,337	1,750	1,325	1,582	1,524
Interest Income Recognized - without allowance recorded	11	13	28	27	34
Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	130	349	130	349	131
Unpaid Principal Balance - with an allowance recorded	130	349	130	349	131
Related Allowance	29	23	29	23	23
Average Recorded Investment - with an allowance recorded	130	350	130	2,428	1,969
Interest Income Recognized - with an allowance recorded	3	6	9	17	11
Recorded Investment - without allowance recorded	276	4,658	276	4,658	799
Unpaid Principal Balance - without allowance recorded	435	4,944	435	4,944	975
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0	0	0
Average Recorded Investment - without allowance recorded	278	4,700	408	2,637	2,269
Interest Income Recognized - without allowance recorded	3		10		13
Commercial
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	442	0	442	0	556
Unpaid Principal Balance - with an allowance recorded	442	0	442	0	556
Related Allowance	303	0	303	0	53
Average Recorded Investment - with an allowance recorded	301		365		111
Recorded Investment - without allowance recorded	204	1,548	204	1,548	230
Unpaid Principal Balance - without allowance recorded	267	2,725	267	2,725	293
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0	0	0
Average Recorded Investment - without allowance recorded	214	1,580	218	1,666	1,379
Interest Income Recognized - without allowance recorded	1	2	5	6	8
Home Equity
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	318	318	318	318	318
Unpaid Principal Balance - with an allowance recorded	318	318	318	318	318
Related Allowance	69	114	69	114	162
Average Recorded Investment - with an allowance recorded	658	391	573	232	250
Recorded Investment - without allowance recorded	267	55	267	55	124
Unpaid Principal Balance - without allowance recorded	705	206	705	206	305
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0	0	0
Average Recorded Investment - without allowance recorded	131	39	130	213	195
Consumer
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	0	0	0	0	0
Unpaid Principal Balance - with an allowance recorded	0	0	0	0	0
Related Allowance	0	0	0	0	0
Average Recorded Investment - with an allowance recorded					0
Recorded Investment - without allowance recorded	0	0	0	0	6
Unpaid Principal Balance - without allowance recorded	0	0	0	0	13
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0	0	0
Average Recorded Investment - without allowance recorded					1
HPFC Portfolio Segment
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	0	0	0	0	0
Unpaid Principal Balance - with an allowance recorded	0	0	0	0	0
Related Allowance	0	0	0	0	0
Average Recorded Investment - with an allowance recorded					0
Recorded Investment - without allowance recorded	0	0	0	0	0
Unpaid Principal Balance - without allowance recorded	0	0	0	0	0
Impaired Financing Receivable With No Related Allowance Related Allowance	$ 0	$ 0	$ 0	$ 0
Average Recorded Investment - without allowance recorded					$ 0

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