LOANS AND ALLOWANCE FOR LOAN LOSSES (Summary of Impaired Loan Balances and Associated Allowance by Portfolio Segment) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	$ 2,666	$ 4,413	$ 2,841
Unpaid Principal Balance - with an allowance recorded	2,666	4,413	2,841
Related Allowance	447	927	463
Average Recorded Investment - with an allowance recorded	2,753	4,444	3,933
Interest Income Recognized - with an allowance recorded	25	31	121
Recorded Investment - without allowance recorded	1,689	1,851	1,637
Unpaid Principal Balance - without allowance recorded	2,533	2,412	2,426
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0
Average Recorded Investment - without allowance recorded	1,664	2,147	1,993
Interest Income Recognized - without allowance recorded	8	15	41
Impaired Financing Receivable, Recorded Investment	4,355	6,264	4,478
Impaired financing receivable, unpaid principal balance	5,199	6,825	5,267
Impaired Financing Receivable, Average Recorded Investment	4,417	6,591	5,926
Impaired Financing Receivable, Interest Income, Accrual Method	33	46	162
Residential Real Estate
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	2,220	3,454	2,395
Unpaid Principal Balance - with an allowance recorded	2,220	3,454	2,395
Related Allowance	324	553	364
Average Recorded Investment - with an allowance recorded	2,307	3,462	2,989
Interest Income Recognized - with an allowance recorded	24	30	110
Recorded Investment - without allowance recorded	1,066	1,282	989
Unpaid Principal Balance - without allowance recorded	1,247	1,406	1,116
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0
Average Recorded Investment - without allowance recorded	1,028	1,286	1,258
Interest Income Recognized - without allowance recorded	3	10	21
Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	128	131	128
Unpaid Principal Balance - with an allowance recorded	128	131	128
Related Allowance	34	27	30
Average Recorded Investment - with an allowance recorded	128	131	130
Interest Income Recognized - with an allowance recorded	1	1	11
Recorded Investment - without allowance recorded	272	279	274
Unpaid Principal Balance - without allowance recorded	431	455	433
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0
Average Recorded Investment - without allowance recorded	273	539	381
Interest Income Recognized - without allowance recorded	3	3	13
Commercial
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	0	0	0
Unpaid Principal Balance - with an allowance recorded	0	0	0
Related Allowance	0	0	0
Average Recorded Investment - with an allowance recorded		278	292
Recorded Investment - without allowance recorded	299	223	319
Unpaid Principal Balance - without allowance recorded	665	286	685
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0
Average Recorded Investment - without allowance recorded	309	226	238
Interest Income Recognized - without allowance recorded	2	2	7
Home Equity
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	318	828	318
Unpaid Principal Balance - with an allowance recorded	318	828	318
Related Allowance	89	347	69
Average Recorded Investment - with an allowance recorded	318	573	522
Recorded Investment - without allowance recorded	52	67	55
Unpaid Principal Balance - without allowance recorded	190	265	192
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0
Average Recorded Investment - without allowance recorded	54	96	115
Consumer
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	0	0	0
Unpaid Principal Balance - with an allowance recorded	0	0	0
Related Allowance	0	0	0
Average Recorded Investment - with an allowance recorded			0
Recorded Investment - without allowance recorded	0	0	0
Unpaid Principal Balance - without allowance recorded	0	0	0
Impaired Financing Receivable With No Related Allowance Related Allowance	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
Unpaid Principal Balance - with an allowance recorded	0	0	0
Related Allowance	0	0	0
Average Recorded Investment - with an allowance recorded			0
Recorded Investment - without allowance recorded	0	0	0
Unpaid Principal Balance - without allowance recorded	0	0	0
Impaired Financing Receivable With No Related Allowance Related Allowance	$ 0	$ 0
Average Recorded Investment - without allowance recorded			$ 0

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