| Document And Entity Information | Oct. 13, 2020 |
| Document Information [Line Items] | |
| Entity, Registrant Name | FutureFuel Corp. |
| Document, Type | 8-K |
| Document, Period End Date | Oct. 13, 2020 |
| Entity, Incorporation, State or Country Code | DE |
| Entity, File Number | 0-52577 |
| Entity, Tax Identification Number | 20-3340900 |
| Entity, Address, Address Line One | 8235 Forsyth Blvd. |
| Entity, Address, Address Line Two | Suite 400 |
| Entity, Address, City or Town | St. Louis |
| Entity, Address, State or Province | MO |
| Entity, Address, Postal Zip Code | 63105 |
| City Area Code | 314 |
| Local Phone Number | 854-8352 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | FF |
| Security Exchange Name | NYSE |
| Entity, Emerging Growth Company | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0001337298 |
