| Document and Entity Information | Feb. 14, 2022 |
| Cover [Abstract] | |
| Amendment Flag | true |
| Amendment Description | On February 16, 2022, Equillium, Inc. (the “Company”) filed a Current Report on Form 8-K (the “Original Form 8-K) with the Securities and Exchange Commission to report its entry into an Agreement and Plan of Merger (the “Merger Agreement”), dated as of February 14, 2022, by and among the Company, Project JetFuel Merger Sub, Inc., a Delaware corporation and wholly owned subsidiary of the Company (“Merger Sub”), Bioniz Therapeutics, Inc., a Delaware corporation (“Bioniz”), and Kevin Green, solely in his capacity as representative of the securityholders of Bioniz. Pursuant to the terms and conditions of the Merger Agreement, Merger Sub merged with and into Bioniz (the “Merger”) whereupon the separate corporate existence of Merger Sub ceased, with Bioniz continuing as the surviving corporation of the Merger as a wholly-owned subsidiary of the Company.This Amendment No. 1 to Current Report on Form 8-K/A (this “Amendment”) amends the Original Form 8-K to include the financial information required under Item 9.01 of Form 8-K. |
| Entity Central Index Key | 0001746466 |
| Document Type | 8-K/A |
| Document Period End Date | Feb. 14, 2022 |
| Entity Registrant Name | Equillium, Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-38692 |
| Entity Tax Identification Number | 82-1554746 |
| Entity Address, Address Line One | 2223 Avenida de la Playa |
| Entity Address, Address Line Two | Suite 105 |
| Entity Address, City or Town | La Jolla |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 92037 |
| City Area Code | 858 |
| Local Phone Number | 412-5302 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, par value $0.0001 per share |
| Trading Symbol | EQ |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
