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Investment Securities - Proceeds from Sale, Gross Gains (Losses) Realized on Sales, Maturities and Other-Than-Temporary Impairment Charges Related to Securities Available for Sale (Detail) (USD $) In Thousands, unless otherwise specified | 12 Months Ended
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Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Investments, Debt and Equity Securities [Abstract] |  |  |
Proceeds from sale | $ 132,868us-gaap_AvailableForSaleSecuritiesGrossRealizedGainsLossesSaleProceeds | $ 671us-gaap_AvailableForSaleSecuritiesGrossRealizedGainsLossesSaleProceeds | $ 0us-gaap_AvailableForSaleSecuritiesGrossRealizedGainsLossesSaleProceeds
Sales Transactions: |  |  |
Gross gains | 291us-gaap_AvailableForSaleSecuritiesGrossRealizedGains | 233us-gaap_AvailableForSaleSecuritiesGrossRealizedGains | 0us-gaap_AvailableForSaleSecuritiesGrossRealizedGains
Gross losses | (243)us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses | 0us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses | 0us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses
Total gain (losses) from sales transactions | 48us-gaap_AvailableforsaleSecuritiesGrossRealizedGainLossExcludingOtherThanTemporaryImpairments | 233us-gaap_AvailableforsaleSecuritiesGrossRealizedGainLossExcludingOtherThanTemporaryImpairments | 0us-gaap_AvailableforsaleSecuritiesGrossRealizedGainLossExcludingOtherThanTemporaryImpairments
Maturities, calls and impairment: |  |  |
Gross gains | 502fcf_GrossGains | 4fcf_GrossGains | 192fcf_GrossGains
Gross losses | 0fcf_GrossLosses | (1,395)fcf_GrossLosses | 0fcf_GrossLosses
Other-than-temporary impairment | 0fcf_OtherThanTemporaryImpairment | 0fcf_OtherThanTemporaryImpairment | 0fcf_OtherThanTemporaryImpairment
Total gain (losses) maturities and impairment | 502fcf_GainLossesMaturitiesAndImpairment | (1,391)fcf_GainLossesMaturitiesAndImpairment | 192fcf_GainLossesMaturitiesAndImpairment
Net gains (losses) and impairment | $ 550fcf_NetGainsAndImpairment | $ (1,158)fcf_NetGainsAndImpairment | $ 192fcf_NetGainsAndImpairment

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- Definition Gain losses maturities and impairment. + References No definition available. + Details
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Balance Type: | credit
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- Definition This item represents the gross gain on maturities of available for sale securities. + References No definition available. + Details
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- Definition This item represents the gross loss on maturities of available for sale securities. + References No definition available. + Details
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- Details
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- Definition Net gains and impairment. + References No definition available. + Details
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- Definition Other-than-temporary impairment. + References No definition available. + Details
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- Definition This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26805-111562 + Details
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- Definition This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563 + Details
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- Definition The total amount of proceeds received for the sale of securities, categorized neither as held-to-maturity nor trading securities, during the reporting period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563 + Details
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- Definition This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563 + Details
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