Revenue Recognition - Disaggregation of net sales (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Revenue, Major Customer [Line Items]
Net sales		$ 1,798	$ 1,460
Acetyl Chain
Revenue, Major Customer [Line Items]
Net sales	[1]	1,034	768
Engineered Materials
Revenue, Major Customer [Line Items]
Net sales		645	563
Acetate Tow
Revenue, Major Customer [Line Items]
Net sales		119	129
Intersegment Eliminations [Member]
Revenue, Major Customer [Line Items]
Net sales	[2]	(22)	(31)
Intersegment Eliminations [Member] | Acetyl Chain
Revenue, Major Customer [Line Items]
Net sales		22	31
North America [Member] | Acetyl Chain
Revenue, Major Customer [Line Items]
Net sales		281	274
North America [Member] | Engineered Materials
Revenue, Major Customer [Line Items]
Net sales		164	162
North America [Member] | Acetate Tow
Revenue, Major Customer [Line Items]
Net sales		28	21
Europe and Africa [Member] | Acetyl Chain
Revenue, Major Customer [Line Items]
Net sales		310	266
Europe and Africa [Member] | Engineered Materials
Revenue, Major Customer [Line Items]
Net sales		296	260
Europe and Africa [Member] | Acetate Tow
Revenue, Major Customer [Line Items]
Net sales		68	71
Asia Pacific [Member] | Acetyl Chain
Revenue, Major Customer [Line Items]
Net sales		423	207
Asia Pacific [Member] | Engineered Materials
Revenue, Major Customer [Line Items]
Net sales		164	123
Asia Pacific [Member] | Acetate Tow
Revenue, Major Customer [Line Items]
Net sales		22	32
South America [Member] | Acetyl Chain
Revenue, Major Customer [Line Items]
Net sales		20	21
South America [Member] | Engineered Materials
Revenue, Major Customer [Line Items]
Net sales		21	18
South America [Member] | Acetate Tow
Revenue, Major Customer [Line Items]
Net sales		$ 1	$ 5

[1] Excludes intersegment sales of $22 million and $31 million for the three months ended March 31, 2021 and 2020, respectively.

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