Borrowed Funds - Terms of the Securities Issued by the Trusts (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Flushing Financial Capital Trust II [Member] \| Capital Securities [Member]
Issue Date	Jun. 20, 2007
Initial Rate	7.14%
First Reset Date	Sep. 01, 2012
Spread over 3-month SOFR\LIBOR	1.41%
Maturity Date	Sep. 01, 2037
Flushing Financial Capital Trust III [Member] \| Capital Securities [Member]
Issue Date	Jun. 21, 2007
Initial Rate	6.89%
First Reset Date	Jun. 15, 2012
Spread over 3-month SOFR\LIBOR	1.44%
Maturity Date	Sep. 15, 2037
Flushing Financial Capital Trust IV [Member] \| Capital Securities [Member]
Issue Date	Jul. 03, 2007
Initial Rate	6.85%
First Reset Date	Jul. 30, 2012
Spread over 3-month SOFR\LIBOR	1.42%
Maturity Date	Jul. 30, 2037
Subordinated Debentures.
Amount	$ 65,000	$ 125,000
$1,25,000 subordinate debentures due December 01, 2031
Amount		$ 125,000
Issue Date		Nov. 22, 2021
Initial Rate		3.125%
First Reset Date		Dec. 01, 2026
First Call Date		Dec. 01, 2026
Maturity Date		Dec. 01, 2031
$1,25,000 subordinate debentures due December 01, 2031 \| London Interbank Offered Rate (LIBOR) [Member]
Spread over 3-month SOFR\LIBOR		2.035%
$65,000 Subordinated debentures due September 1, 2032
Amount	$ 65,000
Issue Date	Aug. 24, 2022
Initial Rate	6.00%
First Reset Date	Sep. 01, 2027
First Call Date	Sep. 01, 2027
Maturity Date	Sep. 01, 2032
$65,000 Subordinated debentures due September 1, 2032 \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread over 3-month SOFR\LIBOR	3.13%

First reset date for the interest rate on the debt instrument.

No definition available.

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

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- Definition

Earliest date before maturity when the issuer can call the outstanding debt instrument for repayment or conversion to equity, in YYYY-MM-DD format.

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- Definition

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

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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- Definition

Date the debt instrument was issued, in YYYY-MM-DD format.

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