Note 3 - Loans (Details) - Impaired Loans (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Mortgage loans:
Recorded Investment, With an allowance recorded	$ 11,312	$ 16,280
Unpaid Principal Balance, With an allowance recorded	11,312	16,376
Related Allowance, With an allowance recorded	1,094	1,648
Average Recorded Investment, With an allowance recorded	13,121	19,972
Interest Income Recognized, With an allowance recorded	615	864
Total Impaired Loans:
Recorded Investment, Total Impaired Loans	56,500	81,800
Related Allowance, Total Impaired Loans	1,094	1,648
Average Recorded Investment, Total Impaired Loans	65,800	95,000
Multi-Family Residential [Member] \| Mortgage Loans [Member]
Mortgage loans:
Recorded Investment, With no related allowance recorded	10,481	18,709
Unpaid Principal Balance, With no related allowance recorded	11,551	20,931
Average Recorded Investment, With no related allowance recorded	14,168	22,091
Interest Income Recognized, With no related allowance recorded	194	402
Mortgage loans:
Recorded Investment, With an allowance recorded	2,779	3,048
Unpaid Principal Balance, With an allowance recorded	2,779	3,049
Related Allowance, With an allowance recorded	286	312
Average Recorded Investment, With an allowance recorded	2,936	2,892
Interest Income Recognized, With an allowance recorded	149	170
Total Impaired Loans:
Related Allowance, Total Impaired Loans	286	312
Multi-Family Residential [Member]
Total Impaired Loans:
Recorded Investment, Total Impaired Loans	16,720	29,029
Commercial Real Estate Loans [Member] \| Mortgage Loans [Member]
Mortgage loans:
Recorded Investment, With no related allowance recorded	7,100	16,721
Unpaid Principal Balance, With no related allowance recorded	7,221	17,405
Average Recorded Investment, With no related allowance recorded	11,329	19,846
Interest Income Recognized, With no related allowance recorded	51	266
Mortgage loans:
Recorded Investment, With an allowance recorded	2,373	3,036
Unpaid Principal Balance, With an allowance recorded	2,373	3,102
Related Allowance, With an allowance recorded	21	164
Average Recorded Investment, With an allowance recorded	3,242	6,388
Interest Income Recognized, With an allowance recorded	167	194
Total Impaired Loans:
Related Allowance, Total Impaired Loans	21	164
Commercial Real Estate Loans [Member]
Total Impaired Loans:
Recorded Investment, Total Impaired Loans	12,553	30,323
One-To-Four Family - Mixed-Use Property [Member] \| Mortgage Loans [Member]
Mortgage loans:
Recorded Investment, With no related allowance recorded	12,027	12,748
Unpaid Principal Balance, With no related allowance recorded	13,381	15,256
Average Recorded Investment, With no related allowance recorded	12,852	13,916
Interest Income Recognized, With no related allowance recorded	321	319
Mortgage loans:
Recorded Investment, With an allowance recorded	3,093	4,191
Unpaid Principal Balance, With an allowance recorded	3,093	4,221
Related Allowance, With an allowance recorded	579	875
Average Recorded Investment, With an allowance recorded	3,249	4,041
Interest Income Recognized, With an allowance recorded	170	228
Total Impaired Loans:
Related Allowance, Total Impaired Loans	579	875
One-To-Four Family - Mixed-Use Property [Member]
Total Impaired Loans:
Recorded Investment, Total Impaired Loans	17,753	22,890
One-To-Four Family - Residential [Member] \| Mortgage Loans [Member]
Mortgage loans:
Recorded Investment, With no related allowance recorded	12,816	14,026
Unpaid Principal Balance, With no related allowance recorded	15,709	17,527
Average Recorded Investment, With no related allowance recorded	13,015	14,529
Interest Income Recognized, With no related allowance recorded	103	125
Mortgage loans:
Recorded Investment, With an allowance recorded	354	364
Unpaid Principal Balance, With an allowance recorded	354	364
Related Allowance, With an allowance recorded	54	58
Average Recorded Investment, With an allowance recorded	358	368
Interest Income Recognized, With an allowance recorded	14	15
Total Impaired Loans:
Related Allowance, Total Impaired Loans	54	58
One-To-Four Family - Residential [Member]
Total Impaired Loans:
Recorded Investment, Total Impaired Loans	15,408	16,874
Co-Operative Apartments [Member] \| Mortgage Loans [Member]
Mortgage loans:
Recorded Investment, With no related allowance recorded		59
Unpaid Principal Balance, With no related allowance recorded		147
Average Recorded Investment, With no related allowance recorded		189
Co-Operative Apartments [Member]
Total Impaired Loans:
Recorded Investment, Total Impaired Loans	623	59
Construction [Member] \| Mortgage Loans [Member]
Mortgage loans:
Unpaid Principal Balance, With no related allowance recorded		118
Average Recorded Investment, With no related allowance recorded	285	4,014
Mortgage loans:
Recorded Investment, With an allowance recorded		746
Unpaid Principal Balance, With an allowance recorded		746
Related Allowance, With an allowance recorded		17
Average Recorded Investment, With an allowance recorded	187	1,929
Interest Income Recognized, With an allowance recorded		18
Total Impaired Loans:
Related Allowance, Total Impaired Loans		17
Construction [Member]
Total Impaired Loans:
Recorded Investment, Total Impaired Loans		746
Small Business Administration [Member] \| Non-Mortgage Loans [Member]
Mortgage loans:
Average Recorded Investment, With no related allowance recorded		247
Small Business Administration [Member]
Total Impaired Loans:
Recorded Investment, Total Impaired Loans	479	310
Commercial Business And Other [Member] \| Non-Mortgage Loans [Member]
Mortgage loans:
Recorded Investment, With no related allowance recorded	2,779	3,225
Unpaid Principal Balance, With no related allowance recorded	3,149	5,527
Average Recorded Investment, With no related allowance recorded	3,428	5,309
Interest Income Recognized, With no related allowance recorded	137	268
Mortgage loans:
Recorded Investment, With an allowance recorded	2,713	4,895
Unpaid Principal Balance, With an allowance recorded	2,713	4,894
Related Allowance, With an allowance recorded	154	222
Average Recorded Investment, With an allowance recorded	3,149	4,354
Interest Income Recognized, With an allowance recorded	115	239
Total Impaired Loans:
Related Allowance, Total Impaired Loans	154	222
Commercial Business And Other [Member]
Total Impaired Loans:
Recorded Investment, Total Impaired Loans	6,620	15,814
Mortgage Loans [Member]
Mortgage loans:
Related Allowance, With an allowance recorded	940	1,426
Total Impaired Loans:
Recorded Investment, Total Impaired Loans	51,023	73,648
Unpaid Principal Balance, Total Impaired Loans	56,461	82,866
Related Allowance, Total Impaired Loans	940	1,426
Average Recorded Investment, Total Impaired Loans	61,621	90,203
Interest Income Recognized, Total Impaired Loans	1,169	1,737
Non-Mortgage Loans [Member]
Mortgage loans:
Recorded Investment, With no related allowance recorded	45,203	65,488
Unpaid Principal Balance, With no related allowance recorded	51,011	76,911
Average Recorded Investment, With no related allowance recorded	55,077	80,141
Interest Income Recognized, With no related allowance recorded	806	1,380
Mortgage loans:
Related Allowance, With an allowance recorded	154	222
Total Impaired Loans:
Recorded Investment, Total Impaired Loans	5,492	8,120
Unpaid Principal Balance, Total Impaired Loans	5,862	10,421
Related Allowance, Total Impaired Loans	154	222
Average Recorded Investment, Total Impaired Loans	6,577	9,910
Interest Income Recognized, Total Impaired Loans	$ 252	$ 507

Name:	ffic_MortgageLoansAbstract
Namespace Prefix:	ffic_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Name:	ffic_MortgageLoansAbstract0
Namespace Prefix:	ffic_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	ffic_TotalImpairedLoansAbstract
Namespace Prefix:	ffic_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5258-111524

+ Details

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

- Definition

Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

+ Details

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

- Definition

Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 14A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953550-111524

+ Details

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

- Definition

Amount of allowance for credit losses related to recorded investment.

+ References

+ Details

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

- Definition

Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

+ References

+ Details

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

- Definition

Amount of average investment of impaired financing receivables for which there is no related allowance for credit losses.

+ References

+ Details

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

- Definition

Amount of interest income, recognized on cash basis, on financing receivables, for which there is no related allowance for credit losses and are recognized as impaired.

+ References

+ Details

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

- Definition

Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.

+ References

+ Details

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

- Definition

Amount of unpaid principal balance of impaired financing receivables for which there is no related allowance for credit losses.

+ References

+ Details

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

- Definition

Amount of average investment of impaired financing receivables for which there is a related allowance for credit losses.

+ References

+ Details

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

- Definition

Amount of interest income on financing receivables, for which there is a related allowance for credit losses, recognized on a cash-basis method of accounting that the financing receivables were impaired.

+ References

+ Details

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

- Definition

Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.

+ References

+ Details

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

- Definition

Unpaid principal balance of impaired financing receivables for which there is a related allowance for credit losses.

+ References

+ Details

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

- Details

Name:	ffic_MortgageReceivableStatusAxis=ffic_MortgageLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ffic_MortgageReceivableStatusAxis=ffic_NonMortgageLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=ffic_CommercialRealEstateLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=ffic_ConstructionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=ffic_CoOperativeApartmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=ffic_MultiFamilyResidentialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=ffic_OneToFourFamilyMixedUsePropertyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=ffic_OneToFourFamilyResidentialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=ffic_SmallBusinessAdministrationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: