Restructuring and Asset Related Charges DowDuPont Agriculture Division Restructuring Program (Details) - USD ($) $ in Millions	3 Months Ended		4 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring and Asset Related Charges - Net	$ 55	$ 97
DowDuPont Agriculture Division Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost				$ 65
Restructuring Reserve, Beginning Balance	54
Restructuring and Asset Related Charges - Net	3		$ 62
Payments for Restructuring	(7)
Asset write-offs and adjustments	(3)
Restructuring Reserve, Ending Balance	47		47
DowDuPont Agriculture Division Restructuring Program [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost				55
Restructuring Reserve, Beginning Balance	54
Restructuring and Asset Related Charges - Net	0		54
Payments for Restructuring	(7)
Asset write-offs and adjustments	0
Restructuring Reserve, Ending Balance	47		47
DowDuPont Agriculture Division Restructuring Program [Member] | Asset Related Charges [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost				8
Restructuring Reserve, Beginning Balance	0
Restructuring and Asset Related Charges - Net	3		8
Payments for Restructuring	0
Asset write-offs and adjustments	(3)
Restructuring Reserve, Ending Balance	$ 0		$ 0
DowDuPont Agriculture Division Restructuring Program [Member] | Costs Related To Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost				$ 2