Restructuring and Asset Related Charges DowDuPont Cost Synergy Program (Details) - USD ($) $ in Millions		3 Months Ended																12 Months Ended			28 Months Ended	40 Months Ended
		Dec. 31, 2020		Sep. 30, 2020	[1]	Jun. 30, 2020	[1]	Mar. 31, 2020		Dec. 31, 2019		Sep. 30, 2019	[1]	Jun. 30, 2019	[1]	Mar. 31, 2019	[1]	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring and asset related charges- net		$ 37	[1]	$ 49		$ 179		$ 70	[1]	$ 55	[1]	$ 46		$ 60		$ 61		$ 335	$ 222	$ 694
Asset Related Charges [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and asset related charges- net																		176
DowDuPont Cost Synergy Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and asset related charges- net																		3
Restructuring Reserve, Beginning Balance								69										69
Payments for Restructuring																		(27)
Asset write-offs																		(7)
Restructuring Reserve, Ending Balance		38								69								38	69		$ 69	$ 38
Restructuring and Asset Related Charges - Net																		0	92	484		845
DowDuPont Cost Synergy Program [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and asset related charges- net																		(2)
Restructuring Reserve, Beginning Balance								29										29
Payments for Restructuring																		(19)
Asset write-offs																		0
Restructuring Reserve, Ending Balance		8								29								8	29		29	8
Restructuring and Asset Related Charges - Net																		(2)	(7)	191	317
DowDuPont Cost Synergy Program [Member] | Costs Related To Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and asset related charges- net	[2]																	0
Restructuring Reserve, Beginning Balance	[2]							40										40
Payments for Restructuring	[2]																	(10)
Asset write-offs	[2]																	0
Restructuring Reserve, Ending Balance	[2]	30								40								30	40		40	30
Restructuring and Asset Related Charges - Net																		0	69	84	193
DowDuPont Cost Synergy Program [Member] | Asset Related Charges [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and asset related charges- net																		5
Restructuring Reserve, Beginning Balance								$ 0										0
Payments for Restructuring																		2
Asset write-offs																		(7)
Restructuring Reserve, Ending Balance		$ 0								$ 0								0	0		0	$ 0
Restructuring and Asset Related Charges - Net																		2	30	209	$ 335
DowDuPont Cost Synergy Program [Member] | Seed [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Asset Related Charges - Net																		(9)	66	237
DowDuPont Cost Synergy Program [Member] | Crop Protection [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Asset Related Charges - Net																		11	27	57
DowDuPont Cost Synergy Program [Member] | Corporate Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Asset Related Charges - Net																		$ (2)	$ (1)	$ 190

[1] See Note 2 - Summary of Significant Accounting Polices, Note 7 - Restructuring and Asset Related Charges - Net, Note 5 - Divestitures and Other Transactions, and Note 15 - Goodwill and Other Intangible Assets, to the Consolidated Financial Statements for additional information related to integration and separation costs, restructuring and asset related charges - net, and discontinued operations, respectively.

[2] Relates primarily to contract terminations charges.