XML 88 R74.htm IDEA: XBRL DOCUMENT
v3.21.2

Subsequent Events (Details) $ in Millions | Sep. 30, 2021 USD ($)
--- | ---
Subsequent Events [Abstract] |
Stock Repurchase Program, Authorized Amount | $ 25.0
Loan Pay Off | 6.9
Specific Reserve Related to Loan Pay Off | $ 0.3

X
- Definition Loan Pay Off + References No definition available. + Details
Name: | fcf_LoanPayOff
Namespace Prefix: | fcf_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Specific Reserve Related to Loan Pay Off + References No definition available. + Details
Name: | fcf_SpecificReserveRelatedToLoanPayOff
Namespace Prefix: | fcf_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of stock repurchase plan authorized. + References No definition available. + Details
Name: | us-gaap_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_SubsequentEventsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration