Business Combinations Fair Value of Consideration Exchanged (Details) - Merger with Dow [Member] $ / shares in Units, $ in Millions	Aug. 31, 2017 USD ($) $ / shares shares
Business Acquisition [Line Items]
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable | $	$ 485	[1]
Business Combination, Consideration Transferred | $	$ 74,680
Common Stock [Member]
Business Acquisition [Line Items]
Share exchange ratio, DuPont to DowDuPont | shares	1.2820
Common Stock [Member] | DuPont [Member]
Business Acquisition [Line Items]
Common Stock, Shares, Outstanding | shares	868,300,000
Common Stock [Member] | DowDuPont [Member]
Business Acquisition [Line Items]
Stock Issued During Period, Shares, New Issues | shares	1,113,200,000
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable | $	$ 74,195	[2]
Common Stock [Member] | Dow [Member]
Business Acquisition [Line Items]
Share Price | $ / shares	$ 66.65

[1] Represents the fair value of replacement awards issued for DuPont's equity awards outstanding immediately before the Merger and attributable to the service periods prior to the Merger. The previous DuPont equity awards were converted into the right to receive 1.2820 shares of DowDuPont Common Stock.

[2] Amount was determined based on the price per share of Dow Common Stock of $66.65 on August 31, 2017.