Stockholders' Equity Common Stock (Details) $ / shares in Units, $ in Millions	3 Months Ended	4 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($) $ / shares shares	Sep. 30, 2019 $ / shares shares	Sep. 30, 2019 USD ($) $ / shares shares	Sep. 30, 2018 USD ($) $ / shares shares	Jun. 26, 2019 USD ($)	Jun. 01, 2019 shares	Dec. 31, 2018 $ / shares shares	Nov. 02, 2017 USD ($)
Class of Stock [Line Items]
Common Stock, Shares, Outstanding	748,390,000	748,390,000	748,390,000
Common Stock, Par Value | $ / shares	$ 0.01	$ 0.01	$ 0.01
Stock Repurchase Program, Authorized Amount | $					$ 1,000			$ 4,000
Payments for Repurchase of Common Stock | $	$ 25		$ 25	$ 0
Corteva [Member]
Class of Stock [Line Items]
Common Stock, Shares, Outstanding	748,390,000	748,390,000	748,390,000			748,815,000
Common Stock, Par Value | $ / shares	$ 0.01	$ 0.01	$ 0.01
Common Stock, Shares, Issued		399,000
Stock Repurchased and Retired During Period, Shares	824,000	(824,000)
Corteva [Member] | Shares of Corteva Stock [Member]
Class of Stock [Line Items]
Exchange Ratio						1
Corteva [Member] | Shares of DowDuPont Common Stock Held [Member]
Class of Stock [Line Items]
Exchange Ratio						3
EID [Member]
Class of Stock [Line Items]
Common Stock, Shares, Outstanding	200	200	200	100			100
Common Stock, Par Value | $ / shares	$ 0.30	$ 0.30	$ 0.30	$ 0.30			$ 0.30
EID [Member] | Corteva [Member]
Class of Stock [Line Items]
Ownership interest in an entity			100.00%