| Document and Entity Information | Feb. 05, 2025 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Feb. 05, 2025 |
| Securities Act File Number | 001-41456 |
| Entity Registrant Name | ECB BANCORP, INC. |
| Entity Central Index Key | 0001914605 |
| Entity Incorporation, State or Country Code | MD |
| Entity Tax Identification Number | 88-1502079 |
| Entity Address, Address Line One | 419 Broadway |
| Entity Address, City or Town | Everett |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 02149 |
| City Area Code | 617 |
| Local Phone Number | 387-1110 |
| Title of 12(b) Security | Common Stock, par value $0.01 per share |
| Trading Symbol | ECBK |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
