Maximum length of time until the line of credit matures.

No definition available.

Name:	ffic_LineOfCreditMaturityMax
Namespace Prefix:	ffic_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Loan commitments expiration period.

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Reflects the weighted average interest rate on commitments to advance to borrowers and lessees at interest rates that increase or decrease depending on certain facts or circumstances.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Reflects the weighted average interest rate associated with agreements to provide advances to borrowers and lessees at stated interest rates.

+ References

No definition available.

+ Details

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

- Definition

Amount of securities, mortgage loans, or other financial instruments pledged as collateral for deposits.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 942
-SubTopic 405
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478353/942-405-50-1

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Reflects the amount of cash required to fully fund agreements to provide advances to borrowers and lessees at stated interest rates.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 942
-SubTopic 825
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478898/942-825-50-2

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 942
-SubTopic 825
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478898/942-825-50-1

+ Details

Name:	us-gaap_LoansAndLeasesReceivableCommitmentsFixedRates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Reflects the amount of cash required to fully fund agreements to provide advances to borrowers and lessees at interest rates that increase or decrease depending on certain facts or circumstances.

+ References

+ Details

Name:	us-gaap_LoansAndLeasesReceivableCommitmentsVariableRates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-14

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Minimum amount of purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier.

+ References

No definition available.

+ Details

Name:	us-gaap_PurchaseObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_SupplyCommitmentAxis=ffic_ExtensionOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=ffic_ThirdPartyVendorsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_HomeEquityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=ffic_CapitalSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=ffic_FlushingFinancialsCapitalTrustsMember
Namespace Prefix:
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Commitments and Contingencies (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Jul. 31, 2007	Jun. 30, 2007	Dec. 31, 2024	Dec. 31, 2023
Loans and Leases Receivable, Commitments, Fixed Rates			$ 5,600
Loans and Leases Receivable, Commitments, Weighted Average Rate of Interest			6.89%
Loans and Leases Receivable, Commitments, Variable Rates			$ 403,900
Loans and Leases Receivable, Commitments, Variable Rates, Weighted Average Rate			7.76%
Loan Commitments, Expiration			90 days
Line of Credit, Maturity, Max			18 months
Purchase obligations			$ 13,325	$ 12,500
Extension of credit
Loans and Leases Receivable, Commitments, Weighted Average Rate of Interest			7.75%
Third-Party Vendors [Member]
Purchase obligations			$ 8,400	6,500
Home Equity Line of Credit [Member]
Line of Credit, Maturity, Max			10 years
Letter of Credit Pledged as Collateral [Member]
Deposit Liabilities, Collateral Issued, Financial Instruments			$ 1,405,700	$ 1,118,700
Capital Securities \| Flushing Financial's Capital Trusts [Member]
Proceeds from Issuance of Debt	$ 61,900	$ 61,900