Planned Merger with DuPont (Notes)	12 Months Ended
Dec. 31, 2016
Statement of Financial Position [Abstract]
Proposed Merger with DuPont [Text Block]	PLANNED MERGER WITH DUPONT On December 11, 2015, Dow and E.I. du Pont de Nemours and Company ("DuPont") entered into an Agreement and Plan of Merger ("Merger Agreement"), to effect an all-stock, merger of equals strategic combination ("Merger Transaction") resulting in a newly formed corporation named DowDuPont Inc. ("DowDuPont"). Pursuant to the terms of the Merger Agreement, Dow and DuPont will each merge with wholly owned subsidiaries of DowDuPont (the "Mergers") and, as a result of the Mergers, will become subsidiaries of DowDuPont. Following the consummation of the Mergers, Dow and DuPont intend to pursue, subject to the receipt of regulatory approvals and approval by the board of directors of DowDuPont, the separation of the combined company’s agriculture business, specialty products business and material science business through one or more tax-efficient transactions. Additional information about the Merger Agreement is included in the Company's Current Report on Form 8-K filed with the U.S. Securities and Exchange Commission ("SEC") on December 11, 2015. Subject to the terms and conditions set forth in the Merger Agreement, at the effective time of the Mergers ("Effective Time"), each share of common stock, par value $2.50 per share, of Dow (the "Dow Common Stock") issued and outstanding immediately prior to the Effective Time (excluding any shares of Dow Common Stock that are held in treasury) will be converted into the right to receive one share of common stock, par value $0.01 per share, of DowDuPont (the "DowDuPont Common Stock"). On December 30, 2016, 4 million issued and outstanding shares of Dow's Cumulative Convertible Perpetual Preferred Stock, Series A ("Dow Preferred Stock"), par value $1.00 per share, were converted into 96.8 million shares of Dow Common Stock. As a result of this conversion, no shares of Dow Preferred Stock remain issued or outstanding and all rights of the holders of the Dow Preferred Stock have terminated. See Note 22 for additional information. Subject to the terms and conditions set forth in the Merger Agreement, at the Effective Time, each share of common stock, par value $0.30 per share, of DuPont (the "DuPont Common Stock") issued and outstanding immediately prior to the Effective Time (excluding any shares of DuPont Common Stock that are held in treasury) will be converted into the right to receive 1.2820 shares of DowDuPont Common Stock, and each share of DuPont Preferred Stock—$4.50 Series and DuPont Preferred Stock—$3.50 Series, in each case issued and outstanding immediately prior to the Effective Time shall remain issued and outstanding and be unaffected by the Mergers. The aforementioned 1.2820 exchange ratio set forth in the Merger Agreement will result in Dow common stockholders and DuPont common stockholders each owning approximately 52 percent and 48 percent, respectively, of the outstanding shares of DowDuPont Common Stock immediately following the Effective Time. The Merger Agreement provides that, at the Effective Time, the Dow stock options and other equity awards and the DuPont stock options and other equity awards generally will automatically convert into stock options and equity awards with respect to DowDuPont Common Stock, on the same terms and conditions under the applicable plans and award agreements immediately prior to the Effective Time and, in the case of DuPont stock options and equity awards, after giving effect to the exchange ratio and appropriate adjustments to reflect the consummation of the Mergers. After the Effective Time, DowDuPont Common Stock will be listed on the New York Stock Exchange. On June 9, 2016, DowDuPont's registration statement filed with the SEC on Form S-4 (File No. 333-209869), as amended, was declared effective. The registration statement was filed in connection with the proposed Mergers and includes a joint proxy statement of Dow and DuPont and a prospectus of DowDuPont. The companies also scheduled special meetings of their respective stockholders to seek adoption of the Merger Agreement and approval of related matters from such stockholders. Each company's common stockholders of record as of the close of business on June 2, 2016, were entitled to vote at the respective meeting. Dow's special meeting of stockholders was held on July 20, 2016, which resulted in a vote for adoption of the Merger Agreement and approval of related matters. On February 2, 2017, the Company announced it reached an agreement to sell its global ethylene acrylic acid ("EAA") copolymers and ionomers business to SK Global Chemical Co., Ltd. as part of the ongoing regulatory approval process for the Merger Transaction. The divestiture will be conditioned on Dow and DuPont closing the Merger Transaction, in addition to other closing conditions, including regulatory filings, local employment law and governance obligations. On February 7, 2017, Dow and DuPont submitted a proposed remedy package to the European Commission (“EC”) which includes the proposed divestment of Dow’s EAA business and a portion of DuPont’s crop protection business and associated research and development. As a result, the EC’s deadline to review the proposed remedy actions has been extended to April 4, 2017. Dow and DuPont remain focused on closing the transaction and continue to work constructively with regulatory agencies in all relevant jurisdictions, including the United States, European Union, China, Brazil and Canada. Given current regulatory agency status, closing is expected to occur in the first half of 2017, subject to satisfaction of customary closing conditions, including receipt of all regulatory approvals.

PLANNED MERGER WITH DUPONT

On December 11, 2015, Dow and E.I. du Pont de Nemours and Company ("DuPont") entered into an Agreement and Plan of Merger ("Merger Agreement"), to effect an all-stock, merger of equals strategic combination ("Merger Transaction") resulting in a newly formed corporation named DowDuPont Inc. ("DowDuPont"). Pursuant to the terms of the Merger Agreement, Dow and DuPont will each merge with wholly owned subsidiaries of DowDuPont (the "Mergers") and, as a result of the Mergers, will become subsidiaries of DowDuPont. Following the consummation of the Mergers, Dow and DuPont intend to pursue, subject to the receipt of regulatory approvals and approval by the board of directors of DowDuPont, the separation of the combined company’s agriculture business, specialty products business and material science business through one or more tax-efficient transactions. Additional information about the Merger Agreement is included in the Company's Current Report on Form 8-K filed with the U.S. Securities and Exchange Commission ("SEC") on December 11, 2015.

Subject to the terms and conditions set forth in the Merger Agreement, at the effective time of the Mergers ("Effective Time"), each share of common stock, par value $2.50 per share, of Dow (the "Dow Common Stock") issued and outstanding immediately prior to the Effective Time (excluding any shares of Dow Common Stock that are held in treasury) will be converted into the right to receive one share of common stock, par value $0.01 per share, of DowDuPont (the "DowDuPont Common Stock"). On December 30, 2016, 4 million issued and outstanding shares of Dow's Cumulative Convertible Perpetual Preferred Stock, Series A ("Dow Preferred Stock"), par value $1.00 per share, were converted into 96.8 million shares of Dow Common Stock. As a result of this conversion, no shares of Dow Preferred Stock remain issued or outstanding and all rights of the holders of the Dow Preferred Stock have terminated. See Note 22 for additional information.

Subject to the terms and conditions set forth in the Merger Agreement, at the Effective Time, each share of common stock, par value $0.30 per share, of DuPont (the "DuPont Common Stock") issued and outstanding immediately prior to the Effective Time (excluding any shares of DuPont Common Stock that are held in treasury) will be converted into the right to receive 1.2820 shares of DowDuPont Common Stock, and each share of DuPont Preferred Stock—$4.50 Series and DuPont Preferred Stock—$3.50 Series, in each case issued and outstanding immediately prior to the Effective Time shall remain issued and outstanding and be unaffected by the Mergers. The aforementioned 1.2820 exchange ratio set forth in the Merger Agreement will result in Dow common stockholders and DuPont common stockholders each owning approximately 52 percent and 48 percent, respectively, of the outstanding shares of DowDuPont Common Stock immediately following the Effective Time.

The Merger Agreement provides that, at the Effective Time, the Dow stock options and other equity awards and the DuPont stock options and other equity awards generally will automatically convert into stock options and equity awards with respect to DowDuPont Common Stock, on the same terms and conditions under the applicable plans and award agreements immediately prior to the Effective Time and, in the case of DuPont stock options and equity awards, after giving effect to the exchange ratio and appropriate adjustments to reflect the consummation of the Mergers.

After the Effective Time, DowDuPont Common Stock will be listed on the New York Stock Exchange.

On June 9, 2016, DowDuPont's registration statement filed with the SEC on Form S-4 (File No. 333-209869), as amended, was declared effective. The registration statement was filed in connection with the proposed Mergers and includes a joint proxy statement of Dow and DuPont and a prospectus of DowDuPont. The companies also scheduled special meetings of their respective stockholders to seek adoption of the Merger Agreement and approval of related matters from such stockholders. Each company's common stockholders of record as of the close of business on June 2, 2016, were entitled to vote at the respective meeting. Dow's special meeting of stockholders was held on July 20, 2016, which resulted in a vote for adoption of the Merger Agreement and approval of related matters.

On February 2, 2017, the Company announced it reached an agreement to sell its global ethylene acrylic acid ("EAA") copolymers and ionomers business to SK Global Chemical Co., Ltd. as part of the ongoing regulatory approval process for the Merger Transaction. The divestiture will be conditioned on Dow and DuPont closing the Merger Transaction, in addition to other closing conditions, including regulatory filings, local employment law and governance obligations. On February 7, 2017, Dow and DuPont submitted a proposed remedy package to the European Commission (“EC”) which includes the proposed divestment of Dow’s EAA business and a portion of DuPont’s crop protection business and associated research and development. As a result, the EC’s deadline to review the proposed remedy actions has been extended to April 4, 2017.

Dow and DuPont remain focused on closing the transaction and continue to work constructively with regulatory agencies in all relevant jurisdictions, including the United States, European Union, China, Brazil and Canada. Given current regulatory agency status, closing is expected to occur in the first half of 2017, subject to satisfaction of customary closing conditions, including receipt of all regulatory approvals.