Pension Plans and Other Post Employment Benefit Plans Basis of Fair Value Measurement (Details) - USD ($) $ in Millions	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Pension Trust Receivables	$ 763	[1]	$ 210	[2]
Pension Trust Payables	(646)	[3]	(208)	[4]
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16,941		18,951		$ 20,329
Investments Measured at Net Asset Value	2,414		2,865
Fair Value of Plan Assets, Excluding Trust Receivables and payables and assets measured at NAV	14,410		16,084
Pension Plan | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,038		8,828	[5]
Pension Plan | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,320		6,926	[5]
Pension Plan | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	52		330	[5]	161
Pension Plan | Cash and Cash Equivalents [Domain]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,343		1,824
Pension Plan | Cash and Cash Equivalents [Domain] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,343		1,824
Pension Plan | Cash and Cash Equivalents [Domain] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Pension Plan | Cash and Cash Equivalents [Domain] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Pension Plan | US Treasury and Government [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,693		3,659
Investments Measured at Net Asset Value	37		208
Pension Plan | US Treasury and Government [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		211
Pension Plan | US Treasury and Government [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,693		3,448
Pension Plan | US Treasury and Government [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Pension Plan | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,956		3,037
Pension Plan | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		253
Pension Plan | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,952		2,770
Pension Plan | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4		14		27
Pension Plan | Asset-backed Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	663		721
Pension Plan | Asset-backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		39
Pension Plan | Asset-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	663		682
Pension Plan | Asset-backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0		2
Pension Plan | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			162
Investments Measured at Net Asset Value	431		678
Pension Plan | Hedge Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			162
Pension Plan | Hedge Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			0
Pension Plan | Hedge Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0		2
Pension Plan | Private Market Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2		1
Investments Measured at Net Asset Value	1,371		1,861
Pension Plan | Private Market Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Pension Plan | Private Market Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Pension Plan | Private Market Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2		1		14
Pension Plan | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	33		336
Investments Measured at Net Asset Value	516		112
Pension Plan | Real Estate [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		243
Pension Plan | Real Estate [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Pension Plan | Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	33		93		96
Pension Plan | Derivative, Asset [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2		10
Pension Plan | Derivative, Asset [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		1
Pension Plan | Derivative, Asset [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2		9
Pension Plan | Derivative, Asset [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Pension Plan | Derivative, Liability [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	(19)		(18)
Pension Plan | Derivative, Liability [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Pension Plan | Derivative, Liability [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	(19)		(18)
Pension Plan | Derivative, Liability [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Pension Plan | Other Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	19		233
Investments Measured at Net Asset Value			6
Pension Plan | Other Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		9
Pension Plan | Other Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	19		18
Pension Plan | Other Investments [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		206		0
Non-US [Member] | Pension Plan | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,053		2,582
Investments Measured at Net Asset Value	39
Non-US [Member] | Pension Plan | Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,043		2,565
Non-US [Member] | Pension Plan | Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6		15
Non-US [Member] | Pension Plan | Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4		2		3
UNITED STATES | Pension Plan | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,665	[6]	3,537	[7]
Investments Measured at Net Asset Value	20
UNITED STATES | Pension Plan | Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,652		3,521
UNITED STATES | Pension Plan | Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4		2
UNITED STATES | Pension Plan | Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 9		14		$ 17
Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Amount of Employer and Related Party Securities Included in Plan Assets, Percent	1.00%
Discontinued Operations [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			1,657
Discontinued Operations [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			392
Discontinued Operations [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			259
Discontinued Operations [Member] | Investments measured at net asset value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			606
Common Stock [Member] | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Amount of Employer and Related Party Securities Included in Plan Assets	$ 126		$ 684
Amount of Employer and Related Party Securities Included in Plan Assets, Percent			4.00%

[1] Primarily receivables for investments securities sold.

[2] Primarily receivables for investments securities sold.

[3] Primarily payables for investment securities purchased.

[4] Primarily payables for investment securities purchased.

[5] Corteva's pension assets by fair value hierarchy at December 31, 2018 included approximately $1,657 million of Level 1 assets, $392 million of Level 2 assets, $259 million of Level 3 assets, and $606 million of investments measured at net asset value that were transferred to DuPont upon completion of the Separation.

[6] The Corteva pension plans directly held $126 million (approximately 1 percent of total plan assets) of Corteva, Inc. common stock at December 31, 2019.

[7] The Corteva pension plans directly held $684 million (approximately 4 percent of total plan assets) of DowDuPont common stock at December 31, 2018.