2017 DWDP Cost Synergy Program (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Nov. 01, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring, Settlement and Impairment Provisions	$ 98	$ (12)	$ 263	$ (13)
DowDuPont Cost Synergy Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost						$ 1,300
Restructuring, Settlement and Impairment Provisions	88		251		$ 687
Restructuring Reserve, Settled without Cash			(75)		(287)
Payments for Restructuring			(167)		(51)
Restructuring Reserve	358		358		349
Employee Severance [Member] | DowDuPont Cost Synergy Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring, Settlement and Impairment Provisions	38		142		357
Restructuring Reserve, Settled without Cash			0		0
Payments for Restructuring			(137)		(51)
Restructuring Reserve	311		311		306
Asset write-downs and write-offs [Member] | DowDuPont Cost Synergy Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring, Settlement and Impairment Provisions	27		75		287
Restructuring Reserve, Settled without Cash			(75)		(287)
Payments for Restructuring			0		0
Restructuring Reserve	0		0		0
Costs Associated with Exit and Disposal Activities [Member] | DowDuPont Cost Synergy Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring, Settlement and Impairment Provisions	23		34		43
Restructuring Reserve, Settled without Cash			0		0
Payments for Restructuring			(30)		0
Restructuring Reserve	47		47		43
Minimum [Member] | Employee Severance [Member] | DowDuPont Cost Synergy Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost						525
Minimum [Member] | Asset write-downs and write-offs [Member] | DowDuPont Cost Synergy Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost						400
Minimum [Member] | Costs Associated with Exit and Disposal Activities [Member] | DowDuPont Cost Synergy Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost						290
Maximum [Member] | Employee Severance [Member] | DowDuPont Cost Synergy Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost						575
Maximum [Member] | Asset write-downs and write-offs [Member] | DowDuPont Cost Synergy Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost						440
Maximum [Member] | Costs Associated with Exit and Disposal Activities [Member] | DowDuPont Cost Synergy Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost						$ 310
Accrued and Other Current Liabilities [Member] | DowDuPont Cost Synergy Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	250		250		231
Other Noncurrent Liabilities [Member] | DowDuPont Cost Synergy Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 108		$ 108		$ 118