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Allowance for Loan Losses - Additional Information (Detail) (USD $) | 3 Months Ended |
--- | --- | ---
Mar. 31, 2015 Contract | Mar. 31, 2014 Contract | Dec. 31, 2014
Allowance For Loan Losses [Line Items] |  |  |
TDRs performing under the restructured terms | $ 1,800,000 us-gaap_FinancingReceivableModificationsRecordedInvestment |  | $ 1,900,000 us-gaap_FinancingReceivableModificationsRecordedInvestment
Loans modified under TDRs | 0 us-gaap_FinancingReceivableModificationsNumberOfContracts2 | 1 us-gaap_FinancingReceivableModificationsNumberOfContracts2 |
Pre-modification recorded investment totaled |  | 283,000 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 |
Post-modification recorded investment totaled |  | 344,000 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 |
Troubled debt restructuring loan subsequent default | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 |
Troubled debt restructuring loan subsequent default period | 90 days |  |
Performing Financing Receivable [Member] |  |  |
Allowance For Loan Losses [Line Items] |  |  |
TDRs performing under the restructured terms | $ 782,000 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_InternalCreditAssessmentAxis = us-gaap_PerformingFinancingReceivableMember |  | $ 790,000 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_InternalCreditAssessmentAxis = us-gaap_PerformingFinancingReceivableMember

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- Definition Financing receivable modification as troubled debt restructuring that subsequently defaulted. + References No definition available. + Details
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- Definition Number of financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953676-111524 + Details
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- Definition Post-modification amount of investment in financing receivables modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953676-111524 + Details
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- Definition Pre-modification amount of investment in financing receivables modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953676-111524 + Details
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- Definition The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18845-111554 + Details
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- Definition Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953682-111524 + Details
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