Quaterly Financial Data Quarterly Financial Data (Parentheticals) (Details) - USD ($) $ in Millions		3 Months Ended							12 Months Ended
		Dec. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Loss on Extinguishment of Debt							$ (13)		$ 0	$ (13)	[1]	$ (81)	[1]
Net after-tax exchange (loss) gain									(161)	(84)		(179)
Hedging Program [Member]
Net after-tax exchange (loss) gain									$ 68	(45)		73
Hedging Program [Member] | Argentine peso devaluation [Member]
Other Tax (Benefit) Expense						$ 33
Merger with Dow [Member]
Business Combination, Fair Value Step-Up Of Acquired Inventory, Amount recognized in Cost of Goods sold						15	$ 52	$ 205		272		$ 1,554
Sale of JV [Member]
Gain (Loss) on Disposition of Assets								$ (24)
Swiss VA [Member]
Other Tax (Benefit) Expense					$ (34)					(34)
Change in accounting method [Member]
Other Tax (Benefit) Expense			$ (29)
State Tax Valuation Allowance [Member]
Other Tax (Benefit) Expense				$ 19
Segment Reconciling Items [Member]
Gain (Loss) on Disposition of Assets	[2],[3]									(24)
Business Combination, Fair Value Step-Up Of Acquired Inventory, Amount recognized in Cost of Goods sold	[3],[4]									(67)
Loss on Extinguishment of Debt	[3],[5]									$ (13)
La Porte
Gain (Loss) on Disposition of Assets				$ (53)
Swiss Tax Reform [Member]
Other Tax (Benefit) Expense		$ (182)				$ (38)

[1] The cash flows for the years ended December 31, 2018 and 2019 includes cash flows of EID's ECP and Specialty Products Entities.

[2] Includes a loss recorded in other income - net related to DAS's sale of a joint venture related to synergy actions.

[3] The years ended December 31, 2019 and December 31, 2018 are presented on a pro forma basis, prepared in accordance with Article 11 of Regulation S-X that was in effect prior to recent amendments.

[4] Includes a charge related to the amortization of the inventory that was stepped up to fair value in connection with the Merger.

[5] Includes a loss on early extinguishment of debt related to the difference between the redemption price and the par value of the Make Whole Notes and Term Loan Facility, partially offset by the write-off of unamortized step-up related to the fair value step-up of EID's debt.