Ratio of shares received by the entity in exchange for a share of the acquiree.

No definition available.

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Namespace Prefix:	ffic_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of investments receivable from affiliates, including but not limited to equity investments receivable and debt investments receivable.

+ References

No definition available.

+ Details

Name:	ffic_InvestmentsReceivableFromAffiliates
Namespace Prefix:	ffic_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Face amount or stated value per share of common stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483399/855-10-50-2

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=ffic_OceanfirstFinancialCorpMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=ffic_FlushingFinancialCorporationMember
Namespace Prefix:
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Period Type:

Subsequent Event (Details) $ / shares in Units, $ in Millions	Dec. 29, 2025 USD ($) $ / shares	Mar. 31, 2026 $ / shares	Dec. 31, 2025 $ / shares
Subsequent Event
Common stock, par value (in dollars per share)		$ 0.01	$ 0.01
OceanFirst Financial Corp
Subsequent Event
Investments receivable from affiliates \| $	$ 225
OceanFirst Financial Corp \| Flushing Financial Corporation
Subsequent Event
Common stock, par value (in dollars per share)	$ 0.01
Business combination, exchange ratio	0.85