Note 7 - Other Real Estate Owned - Gross Gains, Gross Losses and Write-downs of OREO (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Gross gains	$ 0	$ 0	$ 0	$ 27

Represents gross gains on sales of other real estate.

No definition available.

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