| Cover | Jan. 28, 2025 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Jan. 28, 2025 |
| Registrant Name | Chain Bridge Bancorp, Inc. |
| Entity File Number | 001-42302 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 20-4957796 |
| Entity Address, Address Line One | 1445-A Laughlin Avenue |
| Entity Address, City or Town | McLean |
| Entity Address, State or Province | VA |
| Entity Address, Postal Zip Code | 22101 |
| City Area Code | 703 |
| Local Phone Number | 748-2005 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Class A common stock, par value $0.01 per share |
| Trading Symbol | CBNA |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | true |
| Amendment Flag | false |
| Central Index Key | 0001392272 |
