v3.26.1

Derivative Financial Instruments - Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Derivative Financial Instrument
Notional amount, Assets	$ 1,459,786	$ 1,110,599
Notional amount, Liability	1,309,700	1,719,346
Assets Fair Value	34,476	37,900
Liabilities, Fair Value	23,112	31,714
Interest rate swaps (deposits)
Derivative Financial Instrument
Notional amount, Assets	635,800	645,700
Interest rate swaps (deposits) \| Designated as hedging instrument \| Fair value hedges
Derivative Financial Instrument
Notional amount, Assets	400,836
Notional amount, Liability	235,000
Assets Fair Value	11,621
Liabilities, Fair Value	466
Interest rate swaps (deposits) \| Designated as hedging instrument \| Cash flow hedges
Derivative Financial Instrument
Notional amount, Assets	355,000	205,000
Notional amount, Liability	470,750	700,750
Assets Fair Value	1,312	725
Liabilities, Fair Value	1,738	5,398
Interest rate swaps (deposits) \| Not designated as hedging instrument
Derivative Financial Instrument
Notional amount, Assets	603,950	589,240
Notional amount, Liability	603,950	589,240
Assets Fair Value	20,908	24,673
Liabilities, Fair Value	20,908	24,673
Interest rate floors options (loans) \| Designated as hedging instrument \| Fair value hedges
Derivative Financial Instrument
Notional amount, Assets		216,359
Notional amount, Liability		429,356
Assets Fair Value		11,608
Liabilities, Fair Value		1,643
Interest rate floors options (loans) \| Designated as hedging instrument \| Cash flow hedges
Derivative Financial Instrument
Notional amount, Assets	100,000	100,000
Assets Fair Value	$ 635	$ 894

Nominal or face amount used to calculate payments on the derivative asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 320
-Name Accounting Standards Codification
-Section S99
-Paragraph 5
-Subparagraph (SX 210.12-13(Column A)(Footnote 3))
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477271/946-320-S99-5B

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
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-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1B

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4E
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4E

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- Definition

Nominal or face amount used to calculate payments on the derivative liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 320
-Name Accounting Standards Codification
-Section S99
-Paragraph 5C
-Subparagraph (SX 210.12-13C(Column E))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477271/946-320-S99-5C

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 320
-Name Accounting Standards Codification
-Section S99
-Paragraph 5
-Subparagraph (SX 210.12-13(Column D))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477271/946-320-S99-5

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Name Accounting Standards Codification
-Section S99
-Paragraph 5A
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477271/946-320-S99-5A

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477271/946-320-S99-5B

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- Definition

Fair value as of the balance sheet date of interest rate derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets.

+ References

No definition available.

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- Definition

Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities.

+ References

No definition available.

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FLUSHING FINANCIAL CORP 10-Q