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, 2017	Mar. 31, 2016	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	$ 15,235	$ 4,658	$ 14,858
Unpaid Principal Balance - with an allowance recorded	15,235	4,695	14,858
Related Allowance	1,734	1,280	2,007
Average Recorded Investment - with an allowance recorded	15,075	5,184	9,418
Interest Income Recognized - with an allowance recorded	26	27	106
Recorded Investment - without allowance recorded	4,893	9,223	5,396
Unpaid Principal Balance - without allowance recorded	6,893	11,617	7,756
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0
Average Recorded Investment - without allowance recorded	5,166	9,486	6,970
Interest Income Recognized - without allowance recorded	15	17	76
Impaired Financing Receivable, Recorded Investment	20,128	13,881	20,254
Impaired financing receivable, unpaid principal balance	22,128	16,312	22,614
Impaired Financing Receivable, Average Recorded Investment	20,241	14,670	16,388
Impaired Financing Receivable, Interest Income, Accrual Method	41	44	182
Residential Real Estate
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	3,048	3,137	3,019
Unpaid Principal Balance - with an allowance recorded	3,048	3,137	3,019
Related Allowance	485	512	483
Average Recorded Investment - with an allowance recorded	3,025	3,156	3,088
Interest Income Recognized - with an allowance recorded	26	27	106
Recorded Investment - without allowance recorded	1,360	2,896	1,329
Unpaid Principal Balance - without allowance recorded	1,740	3,832	1,800
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0
Average Recorded Investment - without allowance recorded	1,292	2,954	2,057
Interest Income Recognized - without allowance recorded	2	2	9
Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	11,791	540	11,443
Unpaid Principal Balance - with an allowance recorded	11,791	538	11,443
Related Allowance	1,100	158	1,373
Average Recorded Investment - with an allowance recorded	11,654	1,256	5,165
Recorded Investment - without allowance recorded	1,400	2,590	1,874
Unpaid Principal Balance - without allowance recorded	1,707	3,327	2,369
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0
Average Recorded Investment - without allowance recorded	1,704	2,643	2,214
Interest Income Recognized - without allowance recorded	10	11	51
Commercial
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	1	321	0
Unpaid Principal Balance - with an allowance recorded	1	334	0
Related Allowance	0	214	0
Average Recorded Investment - with an allowance recorded		239	762
Recorded Investment - without allowance recorded	1,993	3,541	2,028
Unpaid Principal Balance - without allowance recorded	3,167	3,996	3,209
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0
Average Recorded Investment - without allowance recorded	2,024	3,664	2,507
Interest Income Recognized - without allowance recorded	3	4	16
Home Equity
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	297	303	299
Unpaid Principal Balance - with an allowance recorded	297	303	299
Related Allowance	83	89	86
Average Recorded Investment - with an allowance recorded	298	303	305
Recorded Investment - without allowance recorded	133	189	158
Unpaid Principal Balance - without allowance recorded	269	452	368
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0
Average Recorded Investment - without allowance recorded	139	218	180
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	7	7	7
Unpaid Principal Balance - without allowance recorded	10	10	10
Impaired Financing Receivable With No Related Allowance Related Allowance	0	0
Average Recorded Investment - without allowance recorded	7	7	12
HPFC Portfolio Segment
Financing Receivable, Impaired [Line Items]
Recorded Investment - with an allowance recorded	98	357	97
Unpaid Principal Balance - with an allowance recorded	98	383	97
Related Allowance	66	307	65
Average Recorded Investment - with an allowance recorded	98	230	98
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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