Business Combinations Merger with Dow Narrative (Details) - USD ($) $ / shares in Units, $ in Millions		1 Months Ended		2 Months Ended	3 Months Ended								4 Months Ended	8 Months Ended	12 Months Ended
	Aug. 31, 2017	Sep. 30, 2017		Aug. 31, 2017	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017		Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2017	Aug. 31, 2017	Dec. 31, 2018	Dec. 31, 2016	Aug. 30, 2017
Business Acquisition [Line Items]
Common Stock, Par or Stated Value Per Share					$ 0.30				$ 0.30				$ 0.30		$ 0.30
Goodwill					$ 40,686				$ 45,589				$ 45,589		$ 40,686
Merger with Dow [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	$ 74,680
Equity Awards converted but not yet earned	144
Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Inventory, Finished Goods	4,927			$ 4,927										$ 4,927
Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Inventory, Semi-finished goods	3,055			3,055										3,055
Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Raw Materials and stores and supplies	823			823										823
Property, plant and equipment	11,684			11,684										11,684
Goodwill	45,497			$ 45,497										$ 45,497
Deferred Taxes, Business Combination, Adjustment To Derecognize Valuation Allowance	172
Deferred Taxes, Business Combination, Adjustment For Reinvestment Strategy	$ 546
DuPont [Member]
Business Acquisition [Line Items]
Common Stock, Par or Stated Value Per Share																	$ 0.30
DuPont [Member] | $4.50 Series Preferred Stock [Member]
Business Acquisition [Line Items]
Preferred Stock, Par or Stated Value Per Share																	4.50
DuPont [Member] | $3.50 Series Preferred Stock [Member]
Business Acquisition [Line Items]
Preferred Stock, Par or Stated Value Per Share																	$ 3.50
DowDuPont [Member]
Business Acquisition [Line Items]
Common Stock, Par or Stated Value Per Share	$ 0.01			$ 0.01										$ 0.01
Common Stock [Member] | Merger with Dow [Member]
Business Acquisition [Line Items]
Share exchange ratio, DuPont to DowDuPont	1.2820
Machinery and Equipment [Member] | Merger with Dow [Member]
Business Acquisition [Line Items]
Property, plant and equipment	$ 7,344			$ 7,344										$ 7,344
Building [Member] | Merger with Dow [Member]
Business Acquisition [Line Items]
Property, plant and equipment	2,418			2,418										2,418
Construction in Progress [Member] | Merger with Dow [Member]
Business Acquisition [Line Items]
Property, plant and equipment	995			995										995
Land and Land Improvements [Member] | Merger with Dow [Member]
Business Acquisition [Line Items]
Property, plant and equipment	927			927										927
Successor [Member]
Business Acquisition [Line Items]
Business Combination, Fair Value Step-Up Of Acquired Inventory, Amount recognized in Cost of Goods sold		$ 360			134	$ 109	$ 682	$ 703	1,109				1,469		1,628
Goodwill	45,105			45,105	40,686				45,589				45,589	45,105	40,686
Integration and Separation Costs		$ 71	[1]		$ 449	$ 344	$ 327	$ 255	$ 243	[1]			314		1,375
Successor [Member] | Merger with Dow [Member]
Business Acquisition [Line Items]
Business Combination, Fair Value Step-Up Of Acquired Inventory Recognized Including Discontinued Operations													1,538
Business Combination, Fair Value Step-Up Of Acquired Inventory, Amount recognized in Cost of Goods sold													1,434		$ 1,563
Disposal Group, Including Discontinued Operations, Fair Value Step-Up Of Acquired Inventory Recognized													$ 104
Predecessor [Member]
Business Acquisition [Line Items]
Goodwill	$ 4,543			4,543										4,543		$ 4,169
Integration and Separation Costs				$ 210							$ 201	$ 170		$ 581		$ 386

[1] Integration and separation costs were $170 million, $201 million, and $210 million in the first quarter 2017, second quarter 2017, and the period July 1 - August 31, 2017, respectively. In the Predecessor periods, costs are recorded in selling, general and administrative expenses. See Note 3 for additional information.