Restructuring and Asset Related Charges DowDuPont Cost Synergy Program (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended		37 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring and Asset related charges, net		$ 49	$ 46	$ 298	$ 167
DowDuPont Cost Synergy Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Beginning Balance				69
Payments for Restructuring				(22)
Restructuring Reserve, Ending Balance		45		45		$ 45
Restructuring and Asset related charges, net		9	(8)	6	114	851
DowDuPont Cost Synergy Program [Member] | Severance and Related Benefit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Beginning Balance				29
Payments for Restructuring				(16)
Restructuring Reserve, Ending Balance		13		13		13
Restructuring and Asset related charges, net		0	0	0	14	319
DowDuPont Cost Synergy Program [Member] | Costs Associated with Exit and Disposal Activities
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Beginning Balance	[1]			40
Payments for Restructuring	[1]			(8)
Restructuring Reserve, Ending Balance	[1]	32		32		32
Restructuring and Asset related charges, net		0	0	0	69	193
DowDuPont Cost Synergy Program [Member] | Asset Related Charges [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Asset related charges, net		9	(8)	6	31	$ 339
DowDuPont Cost Synergy Program [Member] | Seed [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Asset related charges, net		(1)	(7)	(7)	66
DowDuPont Cost Synergy Program [Member] | Crop Protection [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Asset related charges, net		10	(1)	13	28
DowDuPont Cost Synergy Program [Member] | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and Asset related charges, net		$ 0	$ 0	$ 0	$ 20

[1] Relates primarily to contract terminations charges.