Cover Page - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Feb. 27, 2026 |
|
| Cover [Abstract] | ||
| Document Type | 10-K/A | |
| Document Annual Report | true | |
| Document Period End Date | Dec. 31, 2025 | |
| Current Fiscal Year End Date | --12-31 | |
| Document Transition Report | false | |
| Entity File Number | 001-35791 | |
| Entity Registrant Name | Northfield Bancorp, Inc. | |
| Entity Incorporation, State or Country Code | DE | |
| Entity Tax Identification Number | 80-0882592 | |
| Entity Address, Address Line One | 581 Main Street, | |
| Entity Address, City or Town | Woodbridge, | |
| Entity Address, State or Province | NJ | |
| Entity Address, Postal Zip Code | 07095 | |
| City Area Code | 732 | |
| Local Phone Number | 499-7200 | |
| Title of 12(b) Security | Common Stock, par value $0.01 per share | |
| Trading Symbol | NFBK | |
| Security Exchange Name | NASDAQ | |
| Entity Well-known Seasoned Issuer | No | |
| Entity Voluntary Filers | No | |
| Entity Current Reporting Status | Yes | |
| Entity Interactive Data Current | Yes | |
| Entity Filer Category | Accelerated Filer | |
| Entity Small Business | false | |
| Entity Emerging Growth Company | false | |
| ICFR Auditor Attestation Flag | true | |
| Document Financial Statement Error Correction [Flag] | false | |
| Entity Shell Company | false | |
| Entity Public Float | $ 437.7 | |
| Entity Common Stock, Shares Outstanding | 41,763,997 | |
| Documents Incorporated by Reference | None. | |
| Amendment Flag | true | |
| Document Fiscal Year Focus | 2025 | |
| Document Fiscal Period Focus | FY | |
| Entity Central Index Key | 0001493225 | |
| Amendment Description | Northfield Bancorp, Inc. (also referred to as the “Bancorp”), the parent of Northfield Bank (collectively the “Company”), is filing this Amendment No. 1 on Form 10-K/A (this “Amendment”) to amend Bancorp's Annual Report on Form 10-K for the year ended December 31, 2025 (the “Original Filing”), as filed with the Securities and Exchange Commission (the “SEC”) on March 2, 2026 (the “Original Filing Date”). Bancorp is filing this Amendment to present the information required by Part III of Form 10-K as Bancorp will not file its definitive annual proxy statement within 120 days of its fiscal year ended December 31, 2025 due to the pending acquisition of Bancorp by Columbia Financial, Inc. Other than the inclusion of information for Part III of the Form 10-K, no other changes have been made to the Original Filing. The Original Filing continues to speak as of the Original Filing Date, and Bancorp has not updated the disclosures contained therein to reflect events that may have occurred subsequent to the Original Filing Date. Accordingly, this Amendment should be read in conjunction with the Original Filing and Bancorp's other filings with the SEC. |
Insider Trading Policies and Procedures |
12 Months Ended |
|---|---|
Dec. 31, 2025 | |
| Insider Trading Policies and Procedures [Line Items] | |
| Insider Trading Policies and Procedures Adopted | true |