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LOANS AND ALLOWANCE FOR LOAN LOSSES (Narrative) (Details) | 3 Months Ended | 9 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Sep. 30, 2018 USD ($) loan | Sep. 30, 2017 USD ($) loan | Sep. 30, 2018 USD ($) loan | Sep. 30, 2017 USD ($) loan | Jun. 30, 2018 USD ($) | Dec. 31, 2017 USD ($) | Jun. 30, 2017 USD ($) | Dec. 31, 2016 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Non-Accrual Loans | $ 14,877,000 |  | $ 14,877,000 |  |  | $ 15,314,000 |  |
Other industry exposures |  |  | 0 |  |  |  |  |
Interest lost on nonaccrual loans | $ 171,000 | $ 187,000 | $ 507,000 | $ 673,000 |  |  |  |
Number of TDRs | loan | 2 | 3 | 3 | 5 |  |  |  |
Loans modified | loan | 0 | 0 | 1 | 0 |  |  |  |
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $ 0 | $ 0 | $ 299,000 | $ 0 |  |  |  |
Financing Receivable, Individually Evaluated for Impairment | 12,112,000 | 13,430,000 | 12,112,000 | 13,430,000 |  | 13,590,000 |  |
Proceeds from the sale of mortgage loans |  |  | 159,740,000 | 155,086,000 |  |  |  |
Gain on sale of mortgage loans |  |  | 4,126,000 | 4,323,000 |  |  |  |
Loans held for sale, at fair value | 10,158,000 |  | 10,158,000 |  |  | 8,103,000 |  |
Financing Receivable, Allowance for Credit Losses | 23,526,000 | 24,413,000 | 23,526,000 | 24,413,000 | $ 23,668,000 | 24,171,000 | $ 24,394,000 | $ 23,116,000
FHLB advances, general debt obligations, pledged collateral | 1,200,000,000 |  | 1,200,000,000 |  |  | 1,100,000,000 |  |
Derivative, Fair Value, Net | 241,000 |  | 241,000 |  |  | 142,000 |  |
Unrealized Gain (Loss) on Derivatives | (46,000) | (60,000) | (38,000) | (283,000) |  |  |  |
Allowance Related to Troubled Debt Restructurings assigned during period | 57,000 | 29,000 | 96,000 | 44,000 |  |  |  |
Loans |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Loans restructured due to credit difficulties that are now performing | 4,000,000 |  | 4,000,000 |  |  | 5,000,000 |  |
Financing receivables impaired TDR non-performing | 1,600,000 |  | 1,600,000 |  |  | 1,200,000 |  |
Residential Real Estate |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Non-Accrual Loans | 4,720,000 |  | 4,720,000 |  |  | 4,979,000 |  |
Financing Receivable, Individually Evaluated for Impairment | 5,184,000 | 4,792,000 | 5,184,000 | 4,792,000 |  | 5,171,000 |  |
Mortgage Loans in Process of Foreclosure, Amount | 1,300,000 |  | 1,300,000 |  |  | 1,900,000 |  |
Financing Receivable, Allowance for Credit Losses | 5,760,000 | 4,542,000 | 5,760,000 | 4,542,000 | 5,779,000 | 5,086,000 | 4,481,000 | 4,160,000
Commercial Real Estate |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Non-Accrual Loans | 5,517,000 |  | 5,517,000 |  |  | 5,642,000 |  |
Financing Receivable, Individually Evaluated for Impairment | 5,007,000 | 6,373,000 | 5,007,000 | 6,373,000 |  | 6,199,000 |  |
Financing Receivable, Allowance for Credit Losses | 10,582,000 | 12,796,000 | 10,582,000 | 12,796,000 | 10,310,000 | 11,863,000 | 12,848,000 | 12,154,000
Commercial |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Non-Accrual Loans | 2,402,000 |  | 2,402,000 |  |  | 2,000,000 |  |
Financing Receivable, Individually Evaluated for Impairment | 1,548,000 | 1,842,000 | 1,548,000 | 1,842,000 |  | 1,791,000 |  |
Financing Receivable, Allowance for Credit Losses | 3,968,000 | 4,221,000 | 3,968,000 | 4,221,000 | 4,303,000 | 4,171,000 | 4,275,000 | 3,755,000
Home Equity |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Non-Accrual Loans | 1,614,000 |  | 1,614,000 |  |  | 1,650,000 |  |
Financing Receivable, Individually Evaluated for Impairment | 373,000 | 423,000 | 373,000 | 423,000 |  | 429,000 |  |
Financing Receivable, Allowance for Credit Losses | 2,575,000 | 2,177,000 | 2,575,000 | 2,177,000 | 2,616,000 | 2,367,000 | 2,094,000 | 2,194,000
Consumer |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Non-Accrual Loans | 33,000 |  | 33,000 |  |  | 0 |  |
Financing Receivable, Individually Evaluated for Impairment | 0 | 0 | 0 | 0 |  |  |  |
Financing Receivable, Allowance for Credit Losses | 273,000 | 195,000 | 273,000 | 195,000 | 260,000 | 233,000 | 182,000 | 181,000
HPFC Portfolio Segment |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Non-Accrual Loans | 591,000 |  | 591,000 |  |  | 1,043,000 |  |
Financing Receivable, Individually Evaluated for Impairment | 0 | 0 | 0 | 0 |  |  |  |
Financing Receivable, Allowance for Credit Losses | 368,000 | 482,000 | 368,000 | 482,000 | $ 400,000 | 451,000 | $ 514,000 | $ 672,000
Fixed Rate Residential Mortgage |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Proceeds from the sale of mortgage loans | 58,400,000 | 59,900,000 | 155,600,000 | 150,800,000 |  |  |  |
Gain on sale of mortgage loans | 1,500,000 | 1,600,000 | 4,100,000 | $ 4,300,000 |  |  |  |
Loans held for sale, at fair value | 10,200,000 |  | 10,200,000 |  |  | 8,100,000 |  |
Home Equity Loan |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Number of TDRs | loan |  |  |  | 1 |  |  |  |
Allowance Related to Troubled Debt Restructurings assigned during period |  |  | 114,000 |  |  |  |  |
Nonoperating Income (Expense) | Fixed Rate Residential Mortgage |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Gain on sale of mortgage loans | $ (99,000) | 72,000 | (67,000) | $ 263,000 |  |  |  |
Unrealized gain (loss) on loans held for sale |  |  | $ (30,000) | 37,000 |  |  |  |
Minimum |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Number of Months | 18 |  | 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 |  | 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) |  |  | 11.00% |  |  |  |  |
Non-Residential Building Operators Industry Sector | Loan Concentration Risk | Commercial Real Estate |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Concentration risk (percentage) |  |  | 25.00% |  |  |  |  |
Substandard (Grade 8) | Minimum |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Individually Evaluated for Impairment | $ 500,000 |  | $ 500,000 |  |  |  |  |
Forward Contracts [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Derivative, Fair Value, Net | 241,000 |  | 241,000 |  |  | $ 142,000 |  |
Unrealized Gain (Loss) on Derivatives | $ 49,000 | $ 16,000 | $ 99,000 | $ 35,000 |  |  |  |

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