XML 78 R67.htm IDEA: XBRL DOCUMENT
v3.21.2

Derivatives - Schedule of Changes in Fair Value of Derivative Assets and Liabilities (Detail) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020
Derivative [Line Items] |  |  |  |
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net | $ (27) | $ 1,672 | $ 309 | $ (753)
Derivative, Gain (Loss) on Derivative, Net | (277) | (221) | 1,153 | (1,962)
Interest Rate Swap [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative Instruments Designated As Hedging Instruments Interest Expense | 236 | 66 | 462 | 11
Forward Contracts [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative, Gain (Loss) on Derivative, Net |  |  | (800) |
Foreign Exchange [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative, Net Hedge Ineffectiveness Gain (Loss) | 3 | 8 | 5 | 12
Designated as Hedging Instrument [Member] | Forward Contracts [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative, Gain (Loss) on Derivative, Net | $ 641 | $ (248) | $ (401) | $ 234

X
- Definition Derivative Instruments Designated As Hedging Instruments Interest Expense + References No definition available. + Details
Name: | fcf_DerivativeInstrumentsDesignatedAsHedgingInstrumentsInterestExpense
Namespace Prefix: | fcf_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5618551-113959 + Details
Name: | us-gaap_DerivativeGainLossOnDerivativeNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4CC -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL109998890-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5624171-113959 + Details
Name: | us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of gain (loss) from the ineffectiveness of the hedge. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 25 -Section 50 -Paragraph 1 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=121577467&loc=d3e76258-113986 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5624171-113959 + Details
Name: | us-gaap_DerivativeNetHedgeIneffectivenessGainLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForwardContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |