Note 9 - Borrowed Funds (Details Textual) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2016
Advances from Federal Home Loan Banks and Letters of Credit	$ 1,794.5
Subordinated Borrowing, Interest Rate		5.25%
Capital Securities [Member] \| Flushing Financial Capital Trust IV [Member]
Proceeds from Issuance of Debt	20.6
Capital Securities [Member] \| Flushing Financial Capital Trust II [Member]
Proceeds from Issuance of Debt	20.6
Capital Securities [Member] \| Flushing Financial Capital Trust III [Member]
Proceeds from Issuance of Debt	20.6
Unsecured Line of Credit [Member]
Long-term Line of Credit, Total	100.0
Federal Home Loan Bank of New York [Member]
Federal Home Loan Bank, Advances, General Debt Obligations, Maximum Amount Available	$ 2,943.0
Federal Home Loan Bank Advances [Member] \| Federal Home Loan Bank of New York [Member] \| Minimum [Member]
Debt Instrument, Term	1 day
Federal Home Loan Bank Advances [Member] \| Federal Home Loan Bank of New York [Member] \| Maximum [Member]
Debt Instrument, Term	5 years
Subordinated Debt [Member]
Debt Instrument, Face Amount		$ 75.0

The amount outstanding of advances from FHLB and Letters of Credit.

No definition available.

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- Definition

Face (par) amount of debt instrument at time of issuance.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of maximum advances or credit lines available from the Federal Home Loan Bank (FHLB).

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

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- Definition

Stated interest rate of the subordinated debt.

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No definition available.

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