Revenue Recognition - Disaggregation of net sales (Details) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 30, 2020		Sep. 30, 2019		Sep. 30, 2020		Sep. 30, 2019
Revenue, Major Customer [Line Items]
Net sales		$ 1,411		$ 1,586		$ 4,064		$ 4,865
Acetyl Chain
Revenue, Major Customer [Line Items]
Net sales	[1]	756		837		2,170		2,530
Engineered Materials
Revenue, Major Customer [Line Items]
Net sales		526		591		1,509		1,847
Acetate Tow
Revenue, Major Customer [Line Items]
Net sales		129		158		385		488
Intersegment Eliminations [Member]
Revenue, Major Customer [Line Items]
Net sales		(20)	[2]	(30)	[2]	(67)	[3]	(91)	[3]
Intersegment Eliminations [Member] | Acetyl Chain
Revenue, Major Customer [Line Items]
Net sales		20		30		67		91
North America [Member] | Acetyl Chain
Revenue, Major Customer [Line Items]
Net sales		246		273		728		837
North America [Member] | Engineered Materials
Revenue, Major Customer [Line Items]
Net sales		147		195		420		571
North America [Member] | Acetate Tow
Revenue, Major Customer [Line Items]
Net sales		24		30		72		97
Europe and Africa [Member] | Acetyl Chain
Revenue, Major Customer [Line Items]
Net sales		251		280		753		856
Europe and Africa [Member] | Engineered Materials
Revenue, Major Customer [Line Items]
Net sales		222		251		665		822
Europe and Africa [Member] | Acetate Tow
Revenue, Major Customer [Line Items]
Net sales		64		63		203		193
Asia Pacific [Member] | Acetyl Chain
Revenue, Major Customer [Line Items]
Net sales		243		264		640		772
Asia Pacific [Member] | Engineered Materials
Revenue, Major Customer [Line Items]
Net sales		141		126		381		400
Asia Pacific [Member] | Acetate Tow
Revenue, Major Customer [Line Items]
Net sales		40		60		101		176
South America [Member] | Acetyl Chain
Revenue, Major Customer [Line Items]
Net sales		16		20		49		65
South America [Member] | Engineered Materials
Revenue, Major Customer [Line Items]
Net sales		16		19		43		54
South America [Member] | Acetate Tow
Revenue, Major Customer [Line Items]
Net sales		$ 1		$ 5		$ 9		$ 22

[1] Excludes intersegment sales of $20 million and $30 million for the three months ended September 30, 2020 and 2019, respectively. Excludes intersegment sales of $67 million and $91 million for the nine months ended September 30, 2020 and 2019, respectively.

[2] Includes intersegment sales primarily related to the Acetyl Chain.

[3] Includes intersegment sales primarily related to the Acetyl Chain.