LOANS AND ALLOWANCE FOR LOAN LOSSES (Summary of Impaired Loan Balances and Associated Allowance by Portfolio Segment) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	$ 4,322	$ 15,196	$ 4,322	$ 15,196	$ 9,280
Unpaid Principal Balance - with an allowance recorded	4,322	15,196	4,322	15,196	9,280
Related Allowance	834	1,704	834	1,704	2,009
Average Recorded Investment - with an allowance recorded	5,802	15,180	6,961	15,128	12,257
Interest Income Recognized - with an allowance recorded	49	40	80	66	153
Recorded Investment - without allowance recorded	8,269	4,884	8,269	4,884	4,310
Unpaid Principal Balance - without allowance recorded	10,126	6,841	10,126	6,841	6,216
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0	0	0
Average Recorded Investment - without allowance recorded	6,106	4,778	5,507	4,971	4,709
Interest Income Recognized - without allowance recorded	4	15	18	30	62
Impaired Financing Receivable, Recorded Investment	12,591	20,080	12,591	20,080	13,590
Impaired financing receivable, unpaid principal balance	14,448	22,037	14,448	22,037	15,496
Impaired Financing Receivable, Average Recorded Investment	11,908	19,958	12,468	20,099	16,966
Impaired Financing Receivable, Interest Income, Accrual Method	53	55	98	96	215
Residential Real Estate
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	3,506	3,026	3,506	3,026	3,858
Unpaid Principal Balance - with an allowance recorded	3,506	3,026	3,506	3,026	3,858
Related Allowance	585	468	585	468	568
Average Recorded Investment - with an allowance recorded	3,525	3,034	3,636	3,030	3,177
Interest Income Recognized - with an allowance recorded	39	29	69	55	131
Recorded Investment - without allowance recorded	1,894	1,425	1,894	1,425	1,313
Unpaid Principal Balance - without allowance recorded	2,200	1,786	2,200	1,786	1,673
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0	0	0
Average Recorded Investment - without allowance recorded	1,704	1,327	1,574	1,310	1,345
Interest Income Recognized - without allowance recorded	7	5	14	7	15
Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	351	12,049	351	12,049	5,422
Unpaid Principal Balance - with an allowance recorded	351	12,049	351	12,049	5,422
Related Allowance	23	1,116	23	1,116	1,441
Average Recorded Investment - with an allowance recorded	1,971	11,901	3,121	11,777	8,900
Interest Income Recognized - with an allowance recorded	10	11	11	11	22
Recorded Investment - without allowance recorded	4,742	1,067	4,742	1,067	777
Unpaid Principal Balance - without allowance recorded	5,080	1,303	5,080	1,303	1,084
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0	0	0
Average Recorded Investment - without allowance recorded	2,556	1,251	1,963	1,477	1,132
Interest Income Recognized - without allowance recorded	(3)	4		14	29
Commercial
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	0	121	0	121	0
Unpaid Principal Balance - with an allowance recorded	0	121	0	121	0
Related Allowance	0	120	0	120	0
Average Recorded Investment - with an allowance recorded		41		21	31
Recorded Investment - without allowance recorded	1,611	1,946	1,611	1,946	1,791
Unpaid Principal Balance - without allowance recorded	2,785	3,120	2,785	3,120	2,964
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0	0	0
Average Recorded Investment - without allowance recorded	1,663	1,962	1,705	1,993	1,920
Interest Income Recognized - without allowance recorded	2	2	4	5	10
Home Equity
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	465	0	465	0	0
Unpaid Principal Balance - with an allowance recorded	465	0	465	0	0
Related Allowance	226	0	226	0	0
Average Recorded Investment - with an allowance recorded	306	204	204	251	125
Recorded Investment - without allowance recorded	22	446	22	446	429
Unpaid Principal Balance - without allowance recorded	61	632	61	632	495
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0	0	0
Average Recorded Investment - without allowance recorded	183	236	265	187	310
Interest Income Recognized - without allowance recorded	(2)	4		4	8
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	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		2		4	2
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				49	24
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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