Inventories Schedule of Inventory (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Sep. 01, 2017
Inventory [Line Items]
Finished Products	$ 2,103	$ 2,611	$ 2,103	$ 2,611	$ 3,022
Semi-finished Products	1,373	1,401	1,373	1,401	1,821
Raw Materials	228	209	228	209	191
Stores and Supplies	214	141	214	141	276
Total	3,918	4,362	3,918	4,362	$ 5,310
Merger with Dow [Member]
Inventory [Line Items]
Business Combination, Fair Value Step Up Of Acquired Inventory						$ 2,297
Business Combination, Fair Value Step-Up Of Acquired Inventory, Amount recognized in Cost of Goods sold	$ 52	$ 676	$ 257	$ 1,315