Goodwill and Other Intangible Assets Other Intangible Assets (Details) - USD ($) $ in Millions		Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		$ 4,474	$ 4,152	$ 4,117
Finite-Lived Intangible Assets, Accumulated Amortization		(1,043)	(820)	(702)
Finite-Lived Intangible Assets, Net		3,431	3,332	3,415
Indefinite-lived Intangible Assets (Excluding Goodwill)		8,236	8,723	8,723
Intangible Assets, Gross (Excluding Goodwill)		12,710	12,875	12,840
Total other intangible assets		11,667	12,055	12,138
In Process Research and Development [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill)	[1],[2]	100	576	576
Germplasm [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill)	[3]	6,265	6,265	6,265
Trademarks and Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill)		1,871	1,871	1,871
Other Intangible Assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill)		0	11	11
Customer-Related Intangible Assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		1,969	1,985	1,987
Finite-Lived Intangible Assets, Accumulated Amortization		(238)	(154)	(125)
Finite-Lived Intangible Assets, Net		1,731	1,831	1,862
Developed Technology Rights [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	[1],[2]	1,463	974	954
Finite-Lived Intangible Assets, Accumulated Amortization	[1],[2]	(332)	(163)	(120)
Finite-Lived Intangible Assets, Net	[1],[2]	1,131	811	834
Trademarks and Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		166	180	171
Finite-Lived Intangible Assets, Accumulated Amortization		(84)	(92)	(79)
Finite-Lived Intangible Assets, Net		82	88	92
Favorable Supply Contract [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		475	475	475
Finite-Lived Intangible Assets, Accumulated Amortization		(183)	(111)	(88)
Finite-Lived Intangible Assets, Net		292	364	387
Other Intangible Assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	[2],[4]	401	538	530
Finite-Lived Intangible Assets, Accumulated Amortization	[2],[4]	(206)	(300)	(290)
Finite-Lived Intangible Assets, Net	[2],[4]	$ 195	$ 238	$ 240

[1] During the first quarter of 2019, the company announced an expanded launch of its Qrome^® corn hybrids following the receipt of regulatory approval from China. As a result, the company reclassified the amounts from indefinite-lived IPR&D to developed technology.

[2] Refer to discussion of interim impairment analysis completed below.

[3] Germplasm is the pool of genetic source material and body of knowledge gained from the development and delivery stage of plant breeding. This intangible asset is expected to contribute to cash flows beyond the foreseeable future and there are no legal, regulatory, contractual, or other factors which limit its useful life.

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