XML 123 R108.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Tax Amortization and Benefits (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Tax Amortization and Benefits [Line Items] |  |  |
Investment, Proportional Amortization Method, Elected, Amount | $ 795 | $ 1,223 | $ 931
Tax credits and other tax benefits recognized | $ 853 | $ 631 | $ 162

X
- Definition Tax Amortization and Benefits [Line Items] + References No definition available. + Details
Name: | fcf_TaxAmortizationAndBenefitsLineItems
Namespace Prefix: | fcf_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tax credits and other tax benefits recognized + References No definition available. + Details
Name: | fcf_TaxCreditsAndOtherTaxBenefitsRecognized
Namespace Prefix: | fcf_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of income tax credit generated by investment under tax credit program elected to be accounted for using proportional amortization method. Includes, but is not limited to, investment under tax credit program not meeting condition for accounting under proportional amortization method. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 323 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478156/740-323-50-1A + Details
Name: | us-gaap_InvestmentProgramProportionalAmortizationMethodElectedIncomeTaxCredit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration