| Document and Entity Information | Oct. 01, 2020 |
| Cover [Abstract] | |
| Entity Registrant Name | ANTARES PHARMA, INC. |
| Document Type | 8-K |
| Amendment Flag | false |
| Entity Central Index Key | 0001016169 |
| Document Period End Date | Oct. 1, 2020 |
| Entity Emerging Growth Company | false |
| Entity File Number | 1-32302 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 41-1350192 |
| Entity Address, Address Line One | 100 Princeton South |
| Entity Address, Address Line Two | Suite 300 |
| Entity Address, City or Town | Ewing |
| Entity Address, State or Province | NJ |
| Entity Address, Postal Zip Code | 08628 |
| City Area Code | (609) |
| Local Phone Number | 359-3020 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.01 per share |
| Trading Symbol | ATRS |
| Security Exchange Name | NASDAQ |
