Revenue Disaggregation of Revenue - Geography (Details) - USD ($) $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Net Sales		$ 5,556	$ 3,396	$ 5,731	$ 8,952	$ 9,525
Crop Protection [Member]
Disaggregation of Revenue [Line Items]
Net Sales		1,857		1,867	3,286	3,360
Crop Protection [Member] | North America
Disaggregation of Revenue [Line Items]
Net Sales	[1]	686		847	1,165	1,419
Crop Protection [Member] | EMEA
Disaggregation of Revenue [Line Items]
Net Sales	[2]	393		420	953	994
Crop Protection [Member] | Asia Pacific
Disaggregation of Revenue [Line Items]
Net Sales		312		284	515	466
Crop Protection [Member] | Latin America
Disaggregation of Revenue [Line Items]
Net Sales		466		316	653	481
Seed [Member]
Disaggregation of Revenue [Line Items]
Net Sales		3,699		3,864	5,666	6,165
Seed [Member] | North America
Disaggregation of Revenue [Line Items]
Net Sales	[1]	3,099		3,279	4,012	4,478
Seed [Member] | EMEA
Disaggregation of Revenue [Line Items]
Net Sales	[2]	274		267	1,078	1,089
Seed [Member] | Asia Pacific
Disaggregation of Revenue [Line Items]
Net Sales		139		147	211	220
Seed [Member] | Latin America
Disaggregation of Revenue [Line Items]
Net Sales		$ 187		$ 171	$ 365	$ 378

[1] Represents U.S. & Canada.

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