Revenue Disaggregation of Revenue - Principal Product Groups (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Net Sales		$ 5,191	$ 5,556	$ 9,147	$ 8,952
Seed [Member]
Disaggregation of Revenue [Line Items]
Net Sales		3,538	3,699	5,993	5,666
Seed [Member] | Corn [Member]
Disaggregation of Revenue [Line Items]
Net Sales		2,057	2,309	3,921	3,777
Seed [Member] | Soybean [Member]
Disaggregation of Revenue [Line Items]
Net Sales		1,085	998	1,266	1,129
Seed [Member] | Other oilseeds [Member]
Disaggregation of Revenue [Line Items]
Net Sales		219	200	467	425
Seed [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Net Sales		177	192	339	335
Crop Protection [Member]
Disaggregation of Revenue [Line Items]
Net Sales		1,653	1,857	3,154	3,286
Crop Protection [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Net Sales	[1]	75	100	146	172
Crop Protection [Member] | Herbicides [Member]
Disaggregation of Revenue [Line Items]
Net Sales	[1]	909	1,003	1,732	1,764
Crop Protection [Member] | Insecticides [Member]
Disaggregation of Revenue [Line Items]
Net Sales	[1]	445	452	823	828
Crop Protection [Member] | Fungicides [Member]
Disaggregation of Revenue [Line Items]
Net Sales	[1]	$ 224	$ 302	$ 453	$ 522

[1] Prior periods have been reclassified to conform to current period presentation.