| Cover | Dec. 15, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Mar. 22, 2023 |
| Securities Act File Number | 001-33013 |
| Entity Registrant Name | FLUSHING FINANCIAL CORPORATION |
| Entity Central Index Key | 0000923139 |
| Entity Tax Identification Number | 11-3209278 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 220 RXR Plaza |
| Entity Address, City or Town | Uniondale |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 11556 |
| City Area Code | 718 |
| Local Phone Number | 961-5400 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.01 par value |
| Trading Symbol | FFIC |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| N-2 | Dec. 15, 2022 |
| Cover [Abstract] | |
| Entity Central Index Key | 0000923139 |
| Amendment Flag | false |
| Securities Act File Number | 001-33013 |
| Document Type | 8-K |
| Entity Registrant Name | FLUSHING FINANCIAL CORPORATION |
| Entity Address, Address Line One | 220 RXR Plaza |
| Entity Address, City or Town | Uniondale |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 11556 |
| City Area Code | 718 |
| Local Phone Number | 961-5400 |
| Entity Emerging Growth Company | false |
