Business Combinations Merger with Dow Narrative (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		6 Months Ended
	Aug. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Aug. 30, 2017
Business Acquisition [Line Items]
Common Stock, Par Value		$ 0.30		$ 0.30		$ 0.30
Merger with Dow [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	$ 74,680
Goodwill, measurement period adjustments				$ 394
Property, plant and equipment, measurement period adjustments				(230)
Other intangible assets, measurement period adjustment				(117)
Assets held for sale, measurement period adjustments				(16)
Other current assets, measurement period adjustments				60
Noncontrolling interest, measurement period adjustments				56
Equity method investments, measurement period adjustments				$ (28)
DuPont [Member]
Business Acquisition [Line Items]
Common Stock, Par Value							$ 0.30
DuPont [Member] | $4.50 Series Preferred Stock [Member]
Business Acquisition [Line Items]
Preferred Stock, Par or Stated Value Per Share		4.50		$ 4.50
DuPont [Member] | $3.50 Series Preferred Stock [Member]
Business Acquisition [Line Items]
Preferred Stock, Par or Stated Value Per Share		$ 3.50		$ 3.50
DowDuPont [Member]
Business Acquisition [Line Items]
Common Stock, Par Value	$ 0.01
Common Stock [Member] | Merger with Dow [Member]
Business Acquisition [Line Items]
Share exchange ratio, DuPont to DowDuPont	1.2820
Successor [Member]
Business Acquisition [Line Items]
Integration and Separation Costs		$ 327		$ 582
Predecessor [Member]
Business Acquisition [Line Items]
Integration and Separation Costs			$ 201		$ 371