Revenue Disaggregation of Revenue - Principal Product Groups (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Net Sales		$ 1,863	$ 1,911	$ 11,010	$ 10,863
Seed [Member]
Disaggregation of Revenue [Line Items]
Net Sales		523	681	6,516	6,347
Seed [Member] | Corn [Member]
Disaggregation of Revenue [Line Items]
Net Sales		303	372	4,224	4,149
Seed [Member] | Soybean [Member]
Disaggregation of Revenue [Line Items]
Net Sales		116	168	1,382	1,297
Seed [Member] | Other oilseeds [Member]
Disaggregation of Revenue [Line Items]
Net Sales		62	44	529	469
Seed [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Net Sales		42	97	381	432
Crop Protection [Member]
Disaggregation of Revenue [Line Items]
Net Sales		1,340	1,230	4,494	4,516
Crop Protection [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Net Sales	[1]	101	81	247	253
Crop Protection [Member] | Herbicides [Member]
Disaggregation of Revenue [Line Items]
Net Sales	[1]	583	574	2,315	2,338
Crop Protection [Member] | Insecticides [Member]
Disaggregation of Revenue [Line Items]
Net Sales	[1]	395	330	1,218	1,158
Crop Protection [Member] | Fungicides [Member]
Disaggregation of Revenue [Line Items]
Net Sales	[1]	$ 261	$ 245	$ 714	$ 767

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