Allowance for losses on loans subject to loss share agreements.

No definition available.

Name:	ffbc_AllowanceForCoveredAssetLosses
Namespace Prefix:	ffbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Allowance for Credit Losses, Covered Loans, Net Charge Offs

+ References

No definition available.

+ Details

Name:	ffbc_AllowanceForCreditLossesCoveredLoansNetChargeOffs
Namespace Prefix:	ffbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Expected reimbursements from the FDIC for losses on covered assets.

+ References

No definition available.

+ Details

Name:	ffbc_FdicIndemnificationIncome
Namespace Prefix:	ffbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The net gain or loss resulting from sales and other disposals of other real estate owned, increases and decreases in the valuation allowance for foreclosed real estate, write-downs of other real estate owned after acquisition or physical possession as well as other expenses recognized during the period on foreclosed real estate properties.

+ References

No definition available.

+ Details

Name:	ffbc_OtherRealEstateOwnedExpense
Namespace Prefix:	ffbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The sum of the periodic provision charged to operations, based on an assessment of the uncollectibility of the loan and lease portfolio on covered loans, the offset to which is either added to or deducted from the allowance account for the purpose of reducing loan receivable and leases to an amount that approximates their net realizable value (the amount expected to be collected).

+ References

No definition available.

+ Details

Name:	ffbc_ProvisionForLoanAndLeaseLossesCovered
Namespace Prefix:	ffbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Restructured Loans, Loan Relationships, Review Threshold Amount for non-impaired and impaired commercial loan relationships less than $250,000

+ References

No definition available.

+ Details

Name:	ffbc_RestructuredLoansLoanRelationshipsReviewThresholdAmountMaximum
Namespace Prefix:	ffbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Restructured Loans, Loan Relationships, Review Threshold Amount Minimum for commercial and other loans greater than $250,000

+ References

No definition available.

+ Details

Name:	ffbc_RestructuredLoansLoanRelationshipsReviewThresholdAmountMinimum
Namespace Prefix:	ffbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=ffbc_CoveredLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

ALLOWANCE FOR LOAN AND LEASE LOSSES - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Provision for loan and lease losses	$ (1,841,000)		$ 195,000	$ 30,903,000
Net charge-offs		7,022,000	26,484,000	28,548,000
FDIC loss sharing income		365,000ffbc_FdicIndemnificationIncome	3,720,000ffbc_FdicIndemnificationIncome	35,346,000ffbc_FdicIndemnificationIncome
Allowance for covered loan losses		10,000,000ffbc_AllowanceForCoveredAssetLosses	18,900,000ffbc_AllowanceForCoveredAssetLosses	45,200,000ffbc_AllowanceForCoveredAssetLosses
Covered Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Loss share expenses primarily related to losses on covered OREO		3,600,000	5,900,000	13,200,000
Commercial \| Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Restructured Loans, Loan Relationships, Review Threshold Amount Minimum		250,000
Residential Portfolio Segment [Member] \| Non Covered Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Restructured loan relationships review threshold		100,000
Restructured Loans, Loan Relationships, Review Threshold Amount Minimum		$ 100,000