| Document and Entity Information | Aug. 13, 2021 |
| Cover [Abstract] | |
| Entity Registrant Name | CONTRAFECT Corp |
| Security Exchange Name | NASDAQ |
| Amendment Flag | false |
| Entity Central Index Key | 0001478069 |
| Document Type | 8-K |
| Document Period End Date | Aug. 13, 2021 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-36577 |
| Entity Tax Identification Number | 39-2072586 |
| Entity Address, Address Line One | 28 Wells Avenue |
| Entity Address, Address Line Two | 3rd Floor |
| Entity Address, City or Town | Yonkers |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10701 |
| City Area Code | (914) |
| Local Phone Number | 207-2300 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, $0.0001 par value per share |
| Trading Symbol | CFRX |
| Entity Emerging Growth Company | false |
