Segment Information (Schedule of Business Segments) (Details) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 30, 2021		Sep. 30, 2020		Sep. 30, 2021		Sep. 30, 2020		Dec. 31, 2020
Segment Reporting Information [Line Items]
Net sales		$ 2,266		$ 1,411		$ 6,262		$ 4,064
Other (charges) gains, net (Note 14)		0		(10)		3		(37)
Operating profit (loss)		536		184		1,429		461
Equity in net earnings (loss) of affiliates		44		25		110		113
Depreciation and amortization		93		89		274		261
Capital expenditures		123	[1]	76	[1]	309	[2]	242	[2]
Goodwill and intangible assets, net		1,434				1,434				$ 1,485
Total assets		11,583				11,583				10,909
Increase (decrease) in accrued capital expenditures		21		4		5		(37)
Acetate Tow
Segment Reporting Information [Line Items]
Net sales		128		129		385		385
Acetyl Chain
Segment Reporting Information [Line Items]
Net sales	[3]	1,454		756		3,866		2,170
Engineered Materials
Segment Reporting Information [Line Items]
Net sales		684		526		2,011		1,509
Operating Segments [Member] | Acetate Tow
Segment Reporting Information [Line Items]
Net sales		128		129		385		385
Other (charges) gains, net (Note 14)		0		0		0		(1)
Operating profit (loss)		12		30		52		88
Equity in net earnings (loss) of affiliates		0		0		0		0
Depreciation and amortization		10		9		29		26
Capital expenditures		10		10		31		26
Goodwill and intangible assets, net		154				154				154
Total assets		1,088				1,088				975
Operating Segments [Member] | Acetyl Chain
Segment Reporting Information [Line Items]
Net sales		1,489		776		3,954		2,237
Other (charges) gains, net (Note 14)		1		1		1		6
Operating profit (loss)		517		121		1,284		377
Equity in net earnings (loss) of affiliates		1		2		5		3
Depreciation and amortization		44		41		128		122
Capital expenditures		73		37		171		118
Goodwill and intangible assets, net		286				286				301
Total assets		4,327				4,327				3,930
Operating Segments [Member] | Engineered Materials
Segment Reporting Information [Line Items]
Net sales		684		526		2,011		1,509
Other (charges) gains, net (Note 14)		0		(10)		6		(35)
Operating profit (loss)		91		84		344		173
Equity in net earnings (loss) of affiliates		39		21		96		100
Depreciation and amortization		35		34		105		100
Capital expenditures		36		21		92		73
Goodwill and intangible assets, net		994				994				1,030
Total assets		4,205				4,205				3,990
Corporate, Non-Segment [Member] | Other
Segment Reporting Information [Line Items]
Net sales		0		0		0		0
Other (charges) gains, net (Note 14)		(1)		(1)		(4)		(7)
Operating profit (loss)		(84)		(51)		(251)		(177)
Equity in net earnings (loss) of affiliates		4		2		9		10
Depreciation and amortization		4		5		12		13
Capital expenditures		4		8		15		25
Goodwill and intangible assets, net		0				0				0
Total assets		1,963				1,963				2,014
Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales		(35)	[4]	(20)	[4]	(88)	[5]	(67)	[5]
Other (charges) gains, net (Note 14)		0		0		0		0
Operating profit (loss)		0		0		0		0
Equity in net earnings (loss) of affiliates		0		0		0		0
Depreciation and amortization		0		0		0		0
Capital expenditures		0		0		0		0
Goodwill and intangible assets, net		0				0				0
Total assets		0				0				$ 0
Eliminations [Member] | Acetyl Chain
Segment Reporting Information [Line Items]
Net sales		$ 35		$ 20		$ 88		$ 67

[1] Includes an increase in accrued capital expenditures of $21 million and $4 million for the three months ended September 30, 2021 and 2020, respectively.

[2] Includes an increase in accrued capital expenditures of $5 million and a decrease of $37 million for the nine months ended September 30, 2021 and 2020, respectively.

[3] Excludes intersegment sales of $35 million and $20 million for the three months ended September 30, 2021 and 2020, respectively. Excludes intersegment sales of $88 million and $67 million for the nine months ended September 30, 2021 and 2020, respectively.

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

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