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Financial Instruments with Off-Balance Sheet Risk (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2016 | Dec. 31, 2015
Commercial lines of credit |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Loan commitments and standby letters of credit, off-balance sheet | $ 216,774 | $ 191,305
Revolving home equity lines |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Loan commitments and standby letters of credit, off-balance sheet | 148,143 | 130,359
Undisbursed construction loans |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Loan commitments and standby letters of credit, off-balance sheet | 44,798 | 39,442
Personal and other lines of credit |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Loan commitments and standby letters of credit, off-balance sheet | 10,635 | 11,112
Standby letters of credit |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Loan commitments and standby letters of credit, off-balance sheet | 1,939 | 4,381
Lines of credit and standby letters of credit, unused |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Loan commitments and standby letters of credit, off-balance sheet | $ 422,289 | 376,599
Percentage of commitments expiring in 2017 | 42.00% |
Percentage of commitments expiring between 2018 and 2024 | 42.00% |
Percentage of commitments expiring 2025 and thereafter | 16.00% |
Lines of credit and standby letters of credit, unused | Interest Payable and Other Liabilities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Allowance for off-balance sheet commitments | $ 899 | $ 749

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