XML 78 R67.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Fair Values of Assets and Liabilities - Quantitative Inputs and Assumptions Used in Level 3 Fair Value Measurements (Detail) - USD ($) | 6 Months Ended |
--- | --- | ---
Jun. 30, 2018 | Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Securities available for sale, at fair value |  | $ 851,243,000 | $ 731,358,000
Assets |  | 892,744,000 | 779,966,000
Equity Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Securities available for sale, at fair value |  | 1,670,000 | 1,670,000
Impaired Loans [Member] | Discounted Cash Flow [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Assets |  | 13,557,000 |
Impaired Loans [Member] | Discounted Cash Flow [Member] | Minimum [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Assets |  | 0 |
Impaired Loans [Member] | Discounted Cash Flow [Member] | Maximum [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Assets |  | 0 |
Impaired Loans [Member] | Reserve Study [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Assets |  | 1,224,000 |
Impaired Loans [Member] | Reserve Study [Member] | NGL per gallon [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Fair Value Inputs Monetary | [1] |  |
Impaired Loans [Member] | Reserve Study [Member] | Minimum [Member] | Gas per MCF [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Fair Value Inputs Monetary | [1] | 2.81 |
Impaired Loans [Member] | Reserve Study [Member] | Minimum [Member] | Oil per BBL/d [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Fair Value Inputs Monetary | [1] | 51.59 |
Impaired Loans [Member] | Reserve Study [Member] | Maximum [Member] | Gas per MCF [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Fair Value Inputs Monetary | [1] | 3.35 |
Impaired Loans [Member] | Reserve Study [Member] | Maximum [Member] | Oil per BBL/d [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Fair Value Inputs Monetary | [1] | $ 59.55 |
Impaired Loans [Member] | Reserve Study [Member] | Weighted average [Member] | Discount rates [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Discount Rate |  | 10.00% |
Limited Partnership Investment [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Assets |  | $ 2,297,000 |
Level 3 [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Securities available for sale, at fair value |  | 1,670,000 | 25,316,000
Assets |  | 3,967,000 | 27,459,000
Level 3 [Member] | Equity Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Securities available for sale, at fair value |  |  | 1,670,000
Assets |  | 1,670,000 |
Pooled Trust Preferred Collateralized Debt Obligations [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Securities available for sale, at fair value |  |  | 23,646,000
Pooled Trust Preferred Collateralized Debt Obligations [Member] | Level 3 [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Securities available for sale, at fair value |  |  | 23,646,000
Fair Value, Measurements, Nonrecurring [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Other Real Estate Owned Assets Fair Value |  | 4,031,000 | 3,264,000
Assets |  | 42,293,000 | 41,758,000
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Other Real Estate Owned Assets Fair Value |  | 0 | 0
Assets |  | $ 25,398,000 | $ 15,245,000
[1] | The remainder of impaired loans valued using Level 3 inputs are not included in this disclosure as the values of those loans are based on bankruptcy agreement documentation.

X
- Definition Fair Value Input, Discount Rate + References No definition available. + Details
Name: | fcf_FairValueInputDiscountRate
Namespace Prefix: | fcf_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair Value Weighted Average Inputs Price + References No definition available. + Details
Name: | fcf_FairValueWeightedAverageInputsPrice
Namespace Prefix: | fcf_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Other real estate owned assets fair value. + References No definition available. + Details
Name: | fcf_OtherRealEstateOwnedAssetsFairValue
Namespace Prefix: | fcf_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=fcf_ImpairedLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=fcf_DiscountedCashFlowMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=fcf_ReserveStudyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | fcf_FairValueMeasurementsSignificantAssumptionsTypeAxis=fcf_NGLperbarrelMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | fcf_FairValueMeasurementsSignificantAssumptionsTypeAxis=fcf_GasperMMBTUMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | fcf_FairValueMeasurementsSignificantAssumptionsTypeAxis=fcf_OilPerBbldMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_WeightedAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | fcf_FairValueMeasurementsSignificantAssumptionsTypeAxis=fcf_DiscountRatesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=fcf_LimitedPartnershipInvestmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_TrustPreferredSecuritiesSubjectToMandatoryRedemptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |