Goodwill and Intangible Assets, net (Schedule of Goodwill) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($)
Goodwill [Line Items]
As of December 31, 2020	$ 1,166
Exchange rate changes	(32)
As of March 31, 2019	1,134	[1]
Goodwill, Impaired, Accumulated Impairment Loss	0
Engineered Materials
Goodwill [Line Items]
As of December 31, 2020	768
Exchange rate changes	(22)
As of March 31, 2019	746	[1]
Acetate Tow
Goodwill [Line Items]
As of December 31, 2020	149
Exchange rate changes	0
As of March 31, 2019	149	[1]
Acetyl Chain
Goodwill [Line Items]
As of December 31, 2020	249
Exchange rate changes	(10)
As of March 31, 2019	$ 239	[1]

[1] There were no accumulated impairment losses as of March 31, 2021.