Other Intangible Assets Other Intangible Assets (Details) - USD ($) $ in Millions		3 Months Ended	9 Months Ended
		Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		$ 4,474	$ 10,735	$ 4,474	$ 10,750
Finite-Lived Intangible Assets, Accumulated Amortization		(1,043)	(1,702)	(1,043)	(1,207)
Finite-Lived Intangible Assets, Net		3,431	9,033	3,431	9,543
Indefinite-lived Intangible Assets (Excluding Goodwill)		8,236	1,881	8,236	1,881
Intangible Assets, Gross (Excluding Goodwill)		12,710	12,616	12,710	12,631
Total other intangible assets		11,667	10,914	11,667	11,424
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)		54		54
Impairment of Intangible Assets Indefinite lived Excluding Goodwill After Tax		41		41
Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill)		1,871	1,871	1,871	1,871
In Process Research and Development [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill)		100	10	100	10
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)		54
Impairment of Intangible Assets Indefinite lived Excluding Goodwill After Tax		41
Germplasm [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill)	[1]	6,265		6,265
Germplasm [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	[1]		6,265		6,265
Finite-Lived Intangible Assets, Accumulated Amortization	[1]		(253)		(63)
Finite-Lived Intangible Assets, Net	[1]		$ 6,012		6,202
Finite-Lived Intangible Asset, Useful Life			25 years
Customer-Related Intangible Assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		1,969	$ 1,966	1,969	1,977
Finite-Lived Intangible Assets, Accumulated Amortization		(238)	(352)	(238)	(268)
Finite-Lived Intangible Assets, Net		1,731	1,614	1,731	1,709
Developed Technology Rights [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		1,463	1,463	1,463	1,463
Finite-Lived Intangible Assets, Accumulated Amortization		(332)	(499)	(332)	(370)
Finite-Lived Intangible Assets, Net		1,131	964	1,131	1,093
Trademarks and Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		166	161	166	166
Finite-Lived Intangible Assets, Accumulated Amortization		(84)	(86)	(84)	(86)
Finite-Lived Intangible Assets, Net		82	75	82	80
Favorable Supply Contract [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		475	475	475	475
Finite-Lived Intangible Assets, Accumulated Amortization		(183)	(279)	(183)	(207)
Finite-Lived Intangible Assets, Net		292	196	292	268
Other Intangible Assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	[2]	401	405	401	404
Finite-Lived Intangible Assets, Accumulated Amortization	[2]	(206)	(233)	(206)	(213)
Finite-Lived Intangible Assets, Net	[2]	$ 195	$ 172	$ 195	$ 191

[1] Beginning on October 1, 2019, the company changed its indefinite life assertion of the germplasm assets to definite lived with a useful life of 25 years.  This change is the result of a more focused development effort of new seed products coupled with an intent to out license select germplasm on a non-exclusive basis. Prior to changing the useful life of the germplasm assets, the company tested the assets for impairment under ASC 350 - Intangibles, Goodwill and Other, concluding the assets were not impaired.

[2] Primarily consists of sales and farmer networks, marketing and manufacturing alliances and noncompetition agreements.