Note 5 - Loans - Activity in the Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Provision (Benefit)
Ending balance	22,157	22,198	22,157	22,198
Beginning balance	22,211	21,993	22,229	21,535
Charge-off's	(350)	(101)	(529)	(248)
Recoveries	296	306	457	911
Multi-family Residential Portfolio Segment [Member]
Provision (Benefit)	(43)	(304)	(75)	(695)
Ending balance	5,917	6,177	5,917	6,177
Beginning balance	5,907	6,298	5,923	6,718
Charge-off's	(148)	(23)	(162)	(65)
Recoveries	201	206	231	219
Commercial Real Estate Portfolio Segment [Member]
Provision (Benefit)	207	244	137	206
Ending balance	4,688	4,445	4,688	4,445
Beginning balance	4,485	4,201	4,487	4,239
Charge-off's	(4)		(4)
Recoveries			68
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member]
Provision (Benefit)	(190)	(145)	(368)	(1,038)
Ending balance	2,568	3,326	2,568	3,326
Beginning balance	2,691	3,507	2,903	4,227
Charge-off's	(1)	(54)	(35)	(68)
Recoveries	68	18	68	205
One-To-Four Family - Residential Portfolio Segment [Member]
Provision (Benefit)	181	9	145	(475)
Ending balance	990	1,044	990	1,044
Beginning balance	979	1,042	1,015	1,227
Charge-off's	(170)	(8)	(170)	(74)
Recoveries		1		366
Construction Portfolio Segment [Member]
Provision (Benefit)	36	20	38	25
Ending balance	130	75	130	75
Beginning balance	94	55	92	50
Charge-off's	0	0	0	0
Recoveries	0	0	0	0
Small Business Administration Portfolio Segment [Member]
Provision (Benefit)	5	263	(135)	239
Ending balance	306	574	306	574
Beginning balance	315	269	481	262
Charge-off's	(24)	(1)	(89)	(1)
Recoveries	10	43	49	74
Taxi Medallion Portfolio Segment [Member]
Provision (Benefit)	117	707	141	699
Ending balance	2,330	1,042	2,330	1,042
Beginning balance	2,213	335	2,243	343
Charge-off's			(54)
Recoveries
Commercial Business and Other Portfolio Segment [Member]
Provision (Benefit)	(58)	55	150	193
Ending balance	4,668	4,669	4,668	4,669
Beginning balance	4,712	4,591	4,492	4,469
Charge-off's	(3)	(15)	(15)	(40)
Recoveries	17	38	41	47
Unallocated Financing Receivables [Member]
Provision (Benefit)	(255)	(849)	(33)	846
Ending balance	560	846	560	846
Beginning balance	815	1,695	593
Charge-off's
Recoveries

A valuation allowance for financing receivables that are expected to be uncollectible.

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

- Definition

Amount of recovery of financing receivables doubtful of collection that were previously charged off.

+ References

+ Details

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

- Definition

Amount of direct write-downs of financing receivables charged against the allowance.

+ References

+ Details

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

- Definition

Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

+ Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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