Earnings Per Share Share Count Information (Details) - shares		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 03, 2019	Jun. 01, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted Average Number of Shares Outstanding, Basic	[1]	749,500,000	749,400,000	749,400,000	749,400,000
Dilutive effect of equity compensation plans	[2]	0	0	0	0
Weighted Average Number of Shares Outstanding, Diluted		749,500,000	749,400,000	749,400,000	749,400,000
Stock options and restricted stock units excluded from EPS	[3]	13,800,000	0	13,800,000	0
Corteva [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common Stock, Shares, Issued						748,815,000
Shares in which vesting conditions were met							600,000

[1] Share amounts for the three and nine months ended September 30, 2018, were based on 748.8 million shares of Corteva, Inc. common stock distributed to holders of DowDuPont's common stock on June 1, 2019, plus 0.6 million of additional shares in which accelerated vesting conditions have been met.

[2] Diluted earnings per share considers the impact of potentially dilutive securities except in periods in which there is a loss because the inclusion of the potential common shares would have an anti-dilutive effect.

[3] These outstanding options to purchase shares of common stock were excluded from the calculation of diluted earnings per share because the effect of including them would have been anti-dilutive.