Significant Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2025
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	**Basis of Presentation** The accompanying unaudited consolidated financial statements have been prepared by FutureFuel Corp. (“FutureFuel” or “the Company”) in accordance and consistent with the accounting policies stated in the Company's 2024 Annual Report on Form 10-K, inclusive of the audited consolidated financial statements, and should be read in conjunction with these consolidated financial statements. Certain reclassifications were made to prior year amounts to conform to the 2025 presentation. In the opinion of FutureFuel, all normal recurring adjustments necessary for a fair presentation have been included in the unaudited consolidated financial statements. The unaudited consolidated financial statements have been prepared in compliance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) accounting principles generally accepted in the United States (“GAAP”) for interim financial information and with instructions to Form 10-Q adopted by the Securities and Exchange Commission (“SEC”). Accordingly, the unaudited consolidated financial statements do not include all the information and footnotes required by GAAP for complete financial statements and do include amounts that are based upon management estimates and judgments. Future actual results could differ from such current estimates. The unaudited consolidated financial statements include assets, liabilities, revenues, and expenses of FutureFuel and its direct and indirect wholly owned subsidiaries; namely, FutureFuel Chemical Company; FutureFuel Warehouse Company, L.L.C.; and Legacy Regional Transport, L.L.C. Intercompany transactions and balances have been eliminated in consolidation. Some of the Company's manufacturing equipment requires periodic, planned shutdowns of significant parts of our facility in order to perform necessary inspections, cleanings, and maintenance activities, referred to as turnarounds. The cost of turnarounds incurred for routine repairs and maintenance or unplanned outages at our facility are expensed as incurred.
New Accounting Pronouncements, Policy [Policy Text Block]	*Recently Adopted Accounting Standards* Accounting standards update (“ASU”) No. 2023-09 Income Taxes (Topic 740): Improvements to Income Tax Disclosures: The FASB issued this ASU in December 2023 which aims to address requests for improved income tax disclosures from investors that use the financial statements to make capital allocation decisions. The amendments in this ASU apply to all entities that are subject to income taxes. The ASU is effective for years beginning after December 15, 2024, but early adoption is permitted. This ASU should be applied on a prospective basis, although retrospective application is permitted. The Company has adopted the new standard effective for the year ended December 31, 2025; however, the required disclosures are effective for our 2025 annual report. The adoption has an immaterial impact on the Company's financial statements but additional disclosures will be included in the notes to the financial statements for the year ended December 31, 2025. Accounting Standards Issued Not Yet Adopted as of September 30, 2025 ASU No.* 2024-03 Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses:* The FASB issued this ASU in November 2024 which aims to provide investors with more useful information about an entity’s expenses by improving disclosures on income statement expenses. The amendments in this ASU require all public business entities to disclose disaggregated information about specific categories underlying certain income statement expense line items. The amendments in this ASU are effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027. Early adoption is permitted. The Company is evaluating this accounting standard and currently does not expect the adoption to have a material impact on its financial statements and disclosures. ASU No.* 2025-06 Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40):* The FASB issued this ASU, which finalizes Proposed ASU No. 2024-ED400 of the same name, in September 2025. This ASU aims to address the challenges of applying current internal-use software accounting requirements (which were issued when companies followed a prescriptive and sequential development method) to software developed under more current, incremental and iterative development methods. This ASU removes all references to a prescriptive and sequential software method, referred to as “project stages”, and requires a company to start capitalizing software costs when management has authorized or committed to funding the project and when it is probable that the project will be completed and the software will perform as intended. The amendments in this ASU are effective for all entities for annual reporting periods beginning after December 15, 2027 and interim reporting periods within those annual reporting periods. Early adoption is permitted as of the beginning of an annual reporting period. The Company is evaluating this accounting standard and currently does not expect the adoption to have a material impact on its financial statements and disclosures.

Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2025

Basis of Accounting, Policy [Policy Text Block]

Basis of Presentation

The accompanying unaudited consolidated financial statements have been prepared by FutureFuel Corp. (“FutureFuel” or “the Company”) in accordance and consistent with the accounting policies stated in the Company's 2024 Annual Report on Form 10-K, inclusive of the audited consolidated financial statements, and should be read in conjunction with these consolidated financial statements. Certain reclassifications were made to prior year amounts to conform to the 2025 presentation.

In the opinion of FutureFuel, all normal recurring adjustments necessary for a fair presentation have been included in the unaudited consolidated financial statements. The unaudited consolidated financial statements have been prepared in compliance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) accounting principles generally accepted in the United States (“GAAP”) for interim financial information and with instructions to Form 10-Q adopted by the Securities and Exchange Commission (“SEC”). Accordingly, the unaudited consolidated financial statements do not include all the information and footnotes required by GAAP for complete financial statements and do include amounts that are based upon management estimates and judgments. Future actual results could differ from such current estimates. The unaudited consolidated financial statements include assets, liabilities, revenues, and expenses of FutureFuel and its direct and indirect wholly owned subsidiaries; namely, FutureFuel Chemical Company; FutureFuel Warehouse Company, L.L.C.; and Legacy Regional Transport, L.L.C. Intercompany transactions and balances have been eliminated in consolidation.

Some of the Company's manufacturing equipment requires periodic, planned shutdowns of significant parts of our facility in order to perform necessary inspections, cleanings, and maintenance activities, referred to as turnarounds. The cost of turnarounds incurred for routine repairs and maintenance or unplanned outages at our facility are expensed as incurred.

New Accounting Pronouncements, Policy [Policy Text Block]

Recently Adopted Accounting Standards

Accounting standards update (“ASU”) No. 2023-09 Income Taxes (Topic 740): Improvements to Income Tax Disclosures: The FASB issued this ASU in December 2023 which aims to address requests for improved income tax disclosures from investors that use the financial statements to make capital allocation decisions. The amendments in this ASU apply to all entities that are subject to income taxes. The ASU is effective for years beginning after December 15, 2024, but early adoption is permitted. This ASU should be applied on a prospective basis, although retrospective application is permitted. The Company has adopted the new standard effective for the year ended December 31, 2025; however, the required disclosures are effective for our 2025 annual report. The adoption has an immaterial impact on the Company's financial statements but additional disclosures will be included in the notes to the financial statements for the year ended December 31, 2025.

Accounting Standards Issued Not Yet Adopted as of September 30, 2025

ASU No. 2024-03 Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses: The FASB issued this ASU in November 2024 which aims to provide investors with more useful information about an entity’s expenses by improving disclosures on income statement expenses. The amendments in this ASU require all public business entities to disclose disaggregated information about specific categories underlying certain income statement expense line items. The amendments in this ASU are effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027. Early adoption is permitted. The Company is evaluating this accounting standard and currently does not expect the adoption to have a material impact on its financial statements and disclosures.

ASU No. 2025-06 Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): The FASB issued this ASU, which finalizes Proposed ASU No. 2024-ED400 of the same name, in September 2025. This ASU aims to address the challenges of applying current internal-use software accounting requirements (which were issued when companies followed a prescriptive and sequential development method) to software developed under more current, incremental and iterative development methods. This ASU removes all references to a prescriptive and sequential software method, referred to as “project stages”, and requires a company to start capitalizing software costs when management has authorized or committed to funding the project and when it is probable that the project will be completed and the software will perform as intended. The amendments in this ASU are effective for all entities for annual reporting periods beginning after December 15, 2027 and interim reporting periods within those annual reporting periods. Early adoption is permitted as of the beginning of an annual reporting period. The Company is evaluating this accounting standard and currently does not expect the adoption to have a material impact on its financial statements and disclosures.