LOANS AND ALLOWANCE FOR LOAN LOSSES (Narrative) (Details)	3 Months Ended
	Mar. 31, 2017 USD ($) loan	Mar. 31, 2016 USD ($) loan	Mar. 31, 2016 USD ($)	Mar. 31, 2016 USD ($)		Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	$ 21,523,000					$ 20,713,000
Other industry exposures	0
Interest lost on nonaccrual loans	$ 210,000			$ 184,000
Number of TDRs	1	0	0
Commitments to lend						0
Loans modified | loan	0	0
Financing Receivable, Individually Evaluated for Impairment	$ 20,128,000	$ 13,881,000	$ 13,881,000	13,881,000
Proceeds from the sale of mortgage loans	44,320,000			39,868,000	[1]
Gain on sale of mortgage loans	1,280,000			972,000	[1]
Loans held for sale, at fair value	5,679,000					14,836,000
Other real estate owned	620,000					922,000
Financing Receivable, Allowance for Credit Losses	23,721,000	21,339,000	21,339,000	21,339,000		23,116,000	$ 21,166,000
FHLB advances, general debt obligations, pledged collateral	1,100,000,000					1,100,000,000
Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans restructured due to credit difficulties that are now performing	4,600,000					4,300,000
Financing receivables impaired TDR non-performing	1,300,000					1,400,000
Residential Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	4,105,000					3,945,000
Financing Receivable, Individually Evaluated for Impairment	4,408,000	6,033,000	6,033,000	6,033,000		4,348,000
Mortgage Loans in Process of Foreclosure, Amount	1,800,000					1,400,000
Financing Receivable, Allowance for Credit Losses	4,271,000	4,516,000	4,516,000	4,516,000		4,160,000	4,545,000
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	12,858,000					12,849,000
Financing Receivable, Individually Evaluated for Impairment	13,191,000	3,130,000	3,130,000	3,130,000		13,317,000
Financing Receivable, Allowance for Credit Losses	12,726,000	10,380,000	10,380,000	10,380,000		12,154,000	10,432,000
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	1,994,000					2,088,000
Financing Receivable, Individually Evaluated for Impairment	1,994,000	3,862,000	3,862,000	3,862,000		2,028,000
Financing Receivable, Allowance for Credit Losses	3,815,000	3,298,000	3,298,000	3,298,000		3,755,000	3,241,000
Home Equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	1,548,000					1,620,000
Financing Receivable, Individually Evaluated for Impairment	430,000	492,000	492,000	492,000		457,000
Financing Receivable, Allowance for Credit Losses	2,107,000	2,622,000	2,622,000	2,622,000		2,194,000	2,731,000
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	4,000					4,000
Financing Receivable, Individually Evaluated for Impairment	7,000	7,000	7,000	7,000		7,000
Financing Receivable, Allowance for Credit Losses	175,000	182,000	182,000	182,000		181,000	193,000
HPFC Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	1,014,000					207,000
Financing Receivable, Individually Evaluated for Impairment	98,000	357,000	357,000	357,000		97,000
Financing Receivable, Allowance for Credit Losses	627,000	$ 341,000	$ 341,000	341,000		672,000	24,000
Unallocated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment						20,254,000
Financing Receivable, Allowance for Credit Losses						23,116,000	$ 21,166,000
Fixed Rate Residential Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from the sale of mortgage loans	43,000,000			38,900,000
Gain on sale of mortgage loans	1,300,000			819,000
Loans held for sale, at fair value	5,700,000					15,100,000
Nonoperating Income (Expense) | Fixed Rate Residential Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gain on sale of mortgage loans	254,000			6,000
Unrealized gain (loss) on loans held for sale	$ 35,000			$ 289,000
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment						$ 250,000
Number of Months	18
Minimum | HPFC Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term to maturity	7 years
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Months	24
Maximum | HPFC Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term to maturity	10 years
Non-Residential Building Operators Industry Sector | Loan Concentration Risk | Total Loan Portfolio
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk (percentage)	13.00%
Non-Residential Building Operators Industry Sector | Loan Concentration Risk | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk (percentage)	31.00%
Substandard (Grade 8) | Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 500,000

[1] (1)The consolidated statement of cash flows for the three months ended March 31, 2016 has been adjusted to reflect the adoption of ASU 2016-09 in the second quarter of 2016 effective as of January 1, 2016.