XML 82 R67.htm IDEA: XBRL DOCUMENT v3.3.1.900

Cash and Due from Banks - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Cash and Due from Banks [Abstract]
Cash or balances held with the Federal Reserve Bank	$ 4.6	$ 4.9

X

- Definition

Average Reserve Balances With Federal Reserve Bank

+ References

No definition available.

+ Details

Name:	fcf_AverageReserveBalancesWithFederalReserveBank
Namespace Prefix:	fcf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- References

No definition available.

+ Details

Name:	us-gaap_CashAndDueFromBanksAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration