Note 8 - Stock-based Compensation - Stock Options Exercised (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Proceeds from stock options exercised		$ 19
Fair value of shares received upon exercised of stock options		328
Tax expense related to stock options exercised		(16)
Intrinsic value of stock options exercised		$ 43

Disclosure of the aggregate tax benefit (expense) realized from the exercise of stock options and the conversion of similar instruments during the annual period.

No definition available.

+ Details

Name:	ffic_EmployeeServiceSharebasedCompensationTaxExpenseBenefitRealizedFromExerciseOfStockOptions
Namespace Prefix:	ffic_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Value of stock issued as a result of the exercise of stock options, before deduction of related income tax (expense) benefit.

+ References

No definition available.

+ Details

Name:	ffic_StockIssuedValueStockOptionsExercisedGrossOfTaxBenefitExpense
Namespace Prefix:	ffic_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of cash inflow from exercise of stock options granted under share-based compensation arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=SL79508275-113901

+ Details

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

- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

+ Details

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