Revenue Disaggregation of Revenue - Geo (Details) - USD ($) $ in Millions		3 Months Ended								4 Months Ended		8 Months Ended	12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017		Aug. 31, 2017	Dec. 31, 2019		Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Net Sales		$ 2,983	$ 1,911	$ 5,556	$ 3,396	$ 2,815	$ 1,947	$ 5,731	$ 3,794	$ 3,790		$ 6,894	$ 13,846		$ 14,287
EMEA
Disaggregation of Revenue [Line Items]
Net Sales										535		1,287	2,740		2,765
Asia Pacific
Disaggregation of Revenue [Line Items]
Net Sales										428		380	1,288		1,293
Latin America
Disaggregation of Revenue [Line Items]
Net Sales										1,603	[1]	648	2,889	[1]	2,817	[1]
Seed [Member]
Disaggregation of Revenue [Line Items]
Net Sales										1,520		5,865	7,590		7,842
Seed [Member] | North America [Member]
Disaggregation of Revenue [Line Items]
Net Sales	[2]									437		4,227	4,724		4,974
Seed [Member] | EMEA
Disaggregation of Revenue [Line Items]
Net Sales	[3]									256		1,017	1,378		1,408
Seed [Member] | Asia Pacific
Disaggregation of Revenue [Line Items]
Net Sales										107		231	358		358
Seed [Member] | Latin America
Disaggregation of Revenue [Line Items]
Net Sales										720		390	1,130		1,102
Crop Protection [Member]
Disaggregation of Revenue [Line Items]
Net Sales										2,270		1,029	6,256		6,445
Crop Protection [Member] | North America [Member]
Disaggregation of Revenue [Line Items]
Net Sales	[2]									787		352	2,205		2,438
Crop Protection [Member] | EMEA
Disaggregation of Revenue [Line Items]
Net Sales	[3]									279		270	1,362		1,357
Crop Protection [Member] | Asia Pacific
Disaggregation of Revenue [Line Items]
Net Sales										321		149	930		935
Crop Protection [Member] | Latin America
Disaggregation of Revenue [Line Items]
Net Sales										$ 883		$ 258	$ 1,759		$ 1,715

[1] Net sales for Brazil for the year ended December 31, 2019, the year ended December 31, 2018 and the period September 1 through December 31, 2017 were $1,794 million, $1,732 million and $1,111 million, respectively. Net sales for Brazil were less than 10 percent of consolidated net sales for the period January 1 through August 31, 2017.

[2] Represents U.S. & Canada.

[3] Europe, Middle East, and Africa ("EMEA").