Goodwill and Other Intangible Assets Goodwill by Segment (Details) - USD ($) $ in Millions		3 Months Ended					4 Months Ended	5 Months Ended		7 Months Ended		8 Months Ended	12 Months Ended
		Dec. 31, 2018	Sep. 30, 2018	[2]	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 01, 2019		Dec. 31, 2019		Aug. 31, 2017	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill Beginning Balance						$ 14,873		$ 10,193		$ 10,179			$ 10,193	$ 14,873
Currency Translation Adjustment								(28)		60				(271)
Measurement period adjustments - Merger	[1]													94
Goodwill Impairment Charge		$ 0	$ (4,503)		$ 0	0	$ 0					$ 0	0	(4,503)
Other goodwill adjustments and acquisitions								14	[3]	(10)	[4]
Segment realignment								0
Goodwill Ending Balance		10,193					14,873	10,179		10,229			10,229	10,193
Agriculture [Member]
Goodwill [Line Items]
Goodwill Beginning Balance						14,873		10,193		0			10,193	14,873
Currency Translation Adjustment								(28)		0				(271)
Measurement period adjustments - Merger	[1]													94
Goodwill Impairment Charge														4,503
Other goodwill adjustments and acquisitions								14	[3]	0	[4]
Segment realignment								(10,179)
Goodwill Ending Balance		10,193					14,873	0		0			0	10,193
Crop Protection [Member]
Goodwill [Line Items]
Goodwill Beginning Balance						0		0		4,726			0	0
Currency Translation Adjustment								0		28				0
Measurement period adjustments - Merger	[1]													0
Other goodwill adjustments and acquisitions								0	[3]	(11)	[4]
Segment realignment								4,726
Goodwill Ending Balance		0					0	4,726		4,743			4,743	0
Seed [Member]
Goodwill [Line Items]
Goodwill Beginning Balance						$ 0		0		5,453			0	0
Currency Translation Adjustment								0		32				0
Measurement period adjustments - Merger	[1]													0
Other goodwill adjustments and acquisitions								0	[3]	1	[4]
Segment realignment								5,453
Goodwill Ending Balance		$ 0					$ 0	$ 5,453		$ 5,486			$ 5,486	0
Goodwill Impairment [Member]
Goodwill [Line Items]
Goodwill Impairment Charge														(4,503)
Goodwill Impairment [Member] | Agriculture [Member]
Goodwill [Line Items]
Goodwill Impairment Charge														(4,503)
Goodwill Impairment [Member] | Crop Protection [Member]
Goodwill [Line Items]
Goodwill Impairment Charge														0
Goodwill Impairment [Member] | Seed [Member]
Goodwill [Line Items]
Goodwill Impairment Charge														$ 0

[1] See Note 1 - Background and Basis of Presentation, for further discussion of the Merger.

[2] Note 7 - Restructuring and Asset Related Charges - Net, Note 5 - Divestitures and Other Transactions, and Note 15 - Goodwill and Other Intangible Assets, for additional information related to integration and separation costs, restructuring and asset related charges - net, discontinued operations, and goodwill impairment charge, respectively.

[3] Primarily consists of the acquisition of a distributor in Greece.

[4] Primarily consists of the goodwill included in the sale of a business in crop protection.