LOANS AND ALLOWANCE FOR LOAN LOSSES (Loan Aging Analysis by Portfolio Segment) (Details)	3 Months Ended
	Mar. 31, 2018 USD ($) loan	Mar. 31, 2017 USD ($) loan	Dec. 31, 2017 USD ($)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of TDRs | loan	0	1
Total Past Due	$ 19,248,000		$ 22,945,000
Current	2,769,900,000		2,759,494,000
Total Loans Outstanding	2,789,148,000	$ 2,645,139,000	2,782,439,000
Loans 90 Days Past Due and Accruing	0		0
Non-Accrual Loans	14,898,000		15,314,000
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0	151,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	0	151,000
Allowance Related to Troubled Debt Restructurings assigned during period	0	15,000
Residential Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	8,264,000		9,477,000
Current	852,269,000		848,892,000
Total Loans Outstanding	860,533,000	819,639,000	858,369,000
Loans 90 Days Past Due and Accruing	0		0
Non-Accrual Loans	6,185,000		4,979,000
Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,694,000		6,700,000
Current	1,163,839,000		1,157,323,000
Total Loans Outstanding	1,169,533,000	1,096,475,000	1,164,023,000
Loans 90 Days Past Due and Accruing	0		0
Non-Accrual Loans	4,603,000		5,642,000
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,779,000		2,223,000
Current	376,236,000		371,177,000
Total Loans Outstanding	378,015,000	333,607,000	373,400,000
Loans 90 Days Past Due and Accruing	0		0
Non-Accrual Loans	1,991,000		2,000,000
Home Equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,305,000		2,548,000
Current	318,337,000		320,830,000
Total Loans Outstanding	320,642,000	322,826,000	323,378,000
Loans 90 Days Past Due and Accruing	0		0
Non-Accrual Loans	1,464,000		1,650,000
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	23,000		67,000
Current	17,988,000		18,082,000
Total Loans Outstanding	18,011,000	16,669,000	18,149,000
Loans 90 Days Past Due and Accruing	0		0
Non-Accrual Loans	0		0
HPFC Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,183,000		1,930,000
Current	41,231,000		43,190,000
Total Loans Outstanding	42,414,000	$ 55,923,000	45,120,000
Loans 90 Days Past Due and Accruing	0		0
Non-Accrual Loans	655,000		1,043,000
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,812,000		6,291,000
30-59 Days Past Due | Residential Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,969,000		3,871,000
30-59 Days Past Due | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,455,000		849,000
30-59 Days Past Due | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	144,000		329,000
30-59 Days Past Due | Home Equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,121,000		1,046,000
30-59 Days Past Due | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	14,000		57,000
30-59 Days Past Due | HPFC Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	109,000		139,000
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,237,000		3,822,000
60-89 Days Past Due | Residential Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	533,000		1,585,000
60-89 Days Past Due | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	72,000		323,000
60-89 Days Past Due | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	103,000		359,000
60-89 Days Past Due | Home Equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	101,000		173,000
60-89 Days Past Due | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	9,000		10,000
60-89 Days Past Due | HPFC Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	419,000		1,372,000
Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	12,199,000		12,832,000
Greater than 90 Days | Residential Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	4,762,000		4,021,000
Greater than 90 Days | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	4,167,000		5,528,000
Greater than 90 Days | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,532,000		1,535,000
Greater than 90 Days | Home Equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,083,000		1,329,000
Greater than 90 Days | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0		0
Greater than 90 Days | HPFC Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 655,000		$ 419,000