Note 5 - Loans - Summary of Interest Foregone on Non-accrual Loans and Loans Classified as TDR (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Interest income that would have been recognized had the loans performed in accordance with their original terms	$ 390	$ 433	$ 798	$ 848
Less: Interest income included in the results of operations	156	141	315	268
Total foregone interest	$ 234	$ 292	$ 483	$ 580

The gross interest income that would have been recorded in the period on troubled debt restructurings and nonaccrual loans, if the loans had been current in accordance with their original terms and had been outstanding throughout the period or since origination, if held for part of the period.

No definition available.

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