Segment Information - Schedule of Business Segments (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2026	Mar. 31, 2025		Dec. 31, 2025
Segment Reporting Information [Line Items]
Net sales		$ 2,337	$ 2,389
Cost of sales		(1,869)	(1,915)
Gross profit		468	474
Selling, general and administrative expenses		(226)	(231)
Amortization		(40)	(40)
Research and development expenses		(28)	(31)
Other (charges) gains, net (Note 18)		(20)	(31)
Gain (loss) on disposition of business and assets, net		48	3
Other segment items(2)	[1]	12	21
Operating profit (loss)		214	165
Depreciation and amortization		201	180
Equity in net earnings (loss) of affiliates		35	22
Capital expenditures	[2]	44	78
Goodwill and intangible assets, net		7,276			$ 7,355
Total assets		21,735			21,695
Increase (decrease) in accrued capital expenditures		(22)	(24)
Engineered Materials
Segment Reporting Information [Line Items]
Net sales		1,325	1,287
Acetyl Chain
Segment Reporting Information [Line Items]
Net sales	[3]	1,012	1,102
Operating Segments | Engineered Materials
Segment Reporting Information [Line Items]
Net sales		1,325	1,287
Cost of sales		(993)	(1,013)
Gross profit		332	274
Selling, general and administrative expenses		(95)	(108)
Amortization		(39)	(40)
Research and development expenses		(18)	(21)
Other (charges) gains, net (Note 18)		(7)	(15)
Gain (loss) on disposition of business and assets, net		48	4
Other segment items(2)		0	0	[1]
Operating profit (loss)		221	94
Depreciation and amortization		107	109
Equity in net earnings (loss) of affiliates		31	16
Capital expenditures		23	39
Goodwill and intangible assets, net		6,843			6,917
Total assets		13,459			13,971
Operating Segments | Acetyl Chain
Segment Reporting Information [Line Items]
Net sales		1,036	1,116
Cost of sales		(895)	(915)
Gross profit		141	201
Selling, general and administrative expenses		(26)	(27)
Amortization		(1)	0
Research and development expenses		(10)	(10)
Other (charges) gains, net (Note 18)		(9)	(3)
Gain (loss) on disposition of business and assets, net		0	0
Other segment items(2)		0	0	[1]
Operating profit (loss)		95	161
Depreciation and amortization		81	61
Equity in net earnings (loss) of affiliates		2	3
Capital expenditures		20	30
Goodwill and intangible assets, net		433			438
Total assets		5,287			5,302
Segment Reporting, Reconciling Item, Corporate Nonsegment | Other
Segment Reporting Information [Line Items]
Net sales		0	0
Cost of sales		(5)	(1)
Gross profit		(5)	(1)
Selling, general and administrative expenses		(105)	(96)
Amortization		0	0
Research and development expenses		0	0
Other (charges) gains, net (Note 18)		(4)	(13)
Gain (loss) on disposition of business and assets, net		0	(1)
Other segment items(2)	[1]	12	21
Operating profit (loss)		(102)	(90)
Depreciation and amortization		13	10
Equity in net earnings (loss) of affiliates		2	3
Capital expenditures		1	9
Goodwill and intangible assets, net		0			0
Total assets		2,989			2,422
Eliminations
Segment Reporting Information [Line Items]
Net sales	[4]	(24)	(14)
Cost of sales		24	14
Gross profit		0	0
Selling, general and administrative expenses		0	0
Amortization		0	0
Research and development expenses		0	0
Other (charges) gains, net (Note 18)		0	0
Gain (loss) on disposition of business and assets, net		0	0
Other segment items(2)	[1]	0	0
Operating profit (loss)		0	0
Depreciation and amortization		0	0
Equity in net earnings (loss) of affiliates		0	0
Capital expenditures		0	0
Goodwill and intangible assets, net		0			0
Total assets		0			$ 0
Eliminations | Acetyl Chain
Segment Reporting Information [Line Items]
Net sales		$ 24	$ 14

[1] Includes Foreign exchange gain (loss), net.

[2] Includes a decrease in accrued capital expenditures of $22 million and $24 million for the three months ended March 31, 2026 and 2025, respectively.

[3] Excludes intersegment sales of $24 million and $14 million for the three months ended March 31, 2026 and 2025, respectively.

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