Basis of Presentation and Nature of the Business	6 Months Ended
Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Nature of the Business	BASIS OF PRESENTATION AND NATURE OF THE BUSINESS The condensed consolidated financial statements have been prepared by Renewable Energy Group, Inc. and its subsidiaries (the "Company" or "REG"), pursuant to the rules and regulations of the U.S. Securities and Exchange Commission ("SEC"). Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") have been condensed or omitted as permitted by such rules and regulations. All adjustments, consisting of normal recurring adjustments, have been included. Management believes that the disclosures are adequate to present fairly the financial position, results of operations and cash flows at the dates and for the periods presented. It is suggested that these interim financial statements be read in conjunction with the consolidated financial statements and the notes thereto appearing in the Company’s latest annual report on Form 10-K filed on March 9, 2018. Results for interim periods are not necessarily indicative of those to be expected for the fiscal year. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts and related disclosures. Actual results could differ from those estimates. As of June 30, 2018, the Company operates a network of fourteen biorefineries, with twelve locations in North America and two locations in Europe, which includes thirteen operating biomass-based diesel production facilities with aggregate nameplate production capacity of 520 million gallons per year ("mmgy") and one fermentation facility. REG also has one feedstock processing facility. Ten of these plants are “multi-feedstock capable” which allows them to use a broad range of lower-cost feedstocks, such as inedible corn oil, used cooking oil and inedible animal fats in addition to vegetable oils, such as soybean oil and canola oil. The biomass-based diesel industry and the Company’s business have benefited from certain federal and state incentives. The federal biodiesel mixture excise tax credit (the "BTC") was retroactively reinstated on February 9, 2018 for the fiscal year 2017, but was not reinstated for 2018 and accordingly we are currently operating without the benefit of the BTC. It is uncertain whether the BTC will be reinstated to apply to 2018. The expiration or modification of any one or more of those incentives, could adversely affect the financial results of the Company.

BASIS OF PRESENTATION AND NATURE OF THE BUSINESS

The condensed consolidated financial statements have been prepared by Renewable Energy Group, Inc. and its subsidiaries (the "Company" or "REG"), pursuant to the rules and regulations of the U.S. Securities and Exchange Commission ("SEC"). Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") have been condensed or omitted as permitted by such rules and regulations. All adjustments, consisting of normal recurring adjustments, have been included. Management believes that the disclosures are adequate to present fairly the financial position, results of operations and cash flows at the dates and for the periods presented. It is suggested that these interim financial statements be read in conjunction with the consolidated financial statements and the notes thereto appearing in the Company’s latest annual report on Form 10-K filed on March 9, 2018. Results for interim periods are not necessarily indicative of those to be expected for the fiscal year.

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts and related disclosures. Actual results could differ from those estimates.

As of June 30, 2018, the Company operates a network of fourteen biorefineries, with twelve locations in North America and two locations in Europe, which includes thirteen operating biomass-based diesel production facilities with aggregate nameplate production capacity of 520 million gallons per year ("mmgy") and one fermentation facility. REG also has one feedstock processing facility. Ten of these plants are “multi-feedstock capable” which allows them to use a broad range of lower-cost feedstocks, such as inedible corn oil, used cooking oil and inedible animal fats in addition to vegetable oils, such as soybean oil and canola oil.

The biomass-based diesel industry and the Company’s business have benefited from certain federal and state incentives. The federal biodiesel mixture excise tax credit (the "BTC") was retroactively reinstated on February 9, 2018 for the fiscal year 2017, but was not reinstated for 2018 and accordingly we are currently operating without the benefit of the BTC. It is uncertain whether the BTC will be reinstated to apply to 2018. The expiration or modification of any one or more of those incentives, could adversely affect the financial results of the Company.