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Commitments and Contingent Liabilities - Additional Information (Detail) - USD ($) $ in Thousands | Sep. 30, 2015 | Dec. 31, 2014
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Loss Contingencies [Line Items] |  |
Notional Amount Of Performance Standby Letters Of Credit | $ 2,300 |
Notional Amount Of Commercial Letters Of Credit | 0 |
Notional Amount Of Financial Standby Letters Of Credit | 7,765 |
Financial instrument of credit risk | 200 | $ 200
Unfunded commitment liability | $ 3,800 | $ 3,100

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