Name:	ffic_FinancingReceivableExcludingAccruedInterestModifiedAfter12Months
Namespace Prefix:	ffic_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amortized cost excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty.

No definition available.

Name:	ffic_FinancingReceivableExcludingAccruedInterestModifiedInPeriodAmount
Namespace Prefix:	ffic_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Percentage, excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty to total financing receivables.

No definition available.

Name:	ffic_FinancingReceivableExcludingAccruedInterestModifiedInPeriodToTotalFinancingReceivablesPercentage
Namespace Prefix:	ffic_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Number of financing receivable that have been modified by troubled debt restructurings to borrowers experiencing financial difficulty.

No definition available.

Name:	ffic_FinancingReceivableModificationsMadeToBorrowersExperiencingFinancialDifficultyNumberOfContracts
Namespace Prefix:	ffic_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Period of increase in weighted average maturity of financing receivable modified for debtor experiencing financial difficulty, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481933/310-10-55-12A

Name:	us-gaap_FinancingReceivableModifiedWeightedAverageTermIncreaseFromModification
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_PaymentDeferralMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancialAssetNotPastDueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancialAssetPastDueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LoanRestructuringModificationAxis=ffic_OtherThanInsignificantPaymentDelayMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LoanRestructuringModificationAxis=ffic_MaturityExtendedToJune2025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LoanRestructuringModificationAxis=ffic_MaturityExtendedToAugust2024Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=ffic_CommercialBusinessAndOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: