Name:	ffic_DepositLiabilities
Namespace Prefix:	ffic_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Weighted average interest rate for certificates of deposit liabilities.

No definition available.

Name:	ffic_WeightedAverageRateDepositCertificatesOfDeposit
Namespace Prefix:	ffic_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

The weighted average interest rate for money market demand account deposit liabilities.

No definition available.

Name:	ffic_WeightedAverageRateDepositMoneyMarket
Namespace Prefix:	ffic_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

Weighted average interest rate for mortgagors' escrow deposits.

No definition available.

Name:	ffic_WeightedAverageRateDepositMortgagorsEscrow
Namespace Prefix:	ffic_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

The weighted average interest rate for NOW demand deposit liabilities.

No definition available.

Name:	ffic_WeightedAverageRateDepositNOWAccounts
Namespace Prefix:	ffic_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

Weighted average interest rate for savings deposit liabilities.

No definition available.

Name:	ffic_WeightedAverageRateDepositSavings
Namespace Prefix:	ffic_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- References

No definition available.

Name:	ffic_statement-statement-note-8-deposits-total-deposits-and-the-weighted-average-rate-on-deposits-details
Namespace Prefix:	ffic_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Carrying amount of accumulated prepayments received by financial institutions from borrowers for taxes (for example, property taxes) and insurance (for example, property and catastrophe) which will periodically be remitted to the appropriate governmental agency or vendor on behalf of the borrower.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.15(5))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1

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

The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.