Unaudited Interim Consolidated Statement of Operations - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Income Statement [Abstract]
Net sales	$ 2,419	$ 2,648	$ 7,340	$ 7,910
Cost of sales	(1,898)	(2,029)	(5,811)	(6,100)
Gross profit	521	619	1,529	1,810
Selling, general and administrative expenses	(231)	(248)	(676)	(770)
Amortization of intangible assets	(42)	(40)	(124)	(119)
Research and development expenses	(31)	(32)	(93)	(99)
Other (charges) gains, net	(1,491)	(61)	(1,542)	(123)
Foreign exchange gain (loss), net	2	10	29	12
Gain (loss) on disposition of business and assets, net	(3)	(3)	(2)	(12)
Operating profit (loss)	(1,275)	245	(879)	699
Equity in net earnings (loss) of affiliates	39	51	90	157
Non-operating pension and other postretirement employee benefit (expense) income	2	3	5	7
Interest expense	(177)	(169)	(524)	(512)
Refinancing expense	0	0	32	0
Interest income	7	5	18	28
Dividend income - equity investments	40	30	82	95
Other income (expense), net	4	15	7	40
Earnings (loss) from continuing operations before tax	(1,360)	180	(1,233)	514
Income tax (provision) benefit	7	(61)	75	(123)
Earnings (loss) from continuing operations	(1,353)	119	(1,158)	391
Earnings (loss) from operation of discontinued operations	0	(3)	(16)	(4)
Income tax (provision) benefit from discontinued operations	0	1	1	1
Earnings (loss) from discontinued operations	0	(2)	(15)	(3)
Net earnings (loss)	(1,353)	117	(1,173)	388
Net (earnings) loss attributable to noncontrolling interests	(4)	(4)	(11)	(5)
Net earnings (loss) attributable to Celanese Corporation	(1,357)	113	(1,184)	383
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations	(1,357)	115	(1,169)	386
Earnings (loss) from discontinued operations	0	(2)	(15)	(3)
Net earnings (loss)	$ (1,357)	$ 113	$ (1,184)	$ 383
Earnings (loss) per common share - basic
Continuing operations - basic (in dollars per share)	$ (12.39)	$ 1.05	$ (10.68)	$ 3.53
Discontinued operations - basic (in dollars per share)	0	(0.02)	(0.13)	(0.02)
Net earnings (loss) - basic (in dollars per share)	(12.39)	1.03	(10.81)	3.51
Earnings (loss) per common share - diluted
Continuing operations - diluted (in dollars per share)	(12.39)	1.05	(10.68)	3.52
Discontinued operations - diluted (in dollars per share)	0	(0.02)	(0.13)	(0.02)
Net earnings (loss) - diluted (in dollars per share)	$ (12.39)	$ 1.03	$ (10.81)	$ 3.50
Weighted average shares - basic (in shares)	109,565,996	109,338,977	109,504,912	109,241,174
Weighted average shares - diluted (in shares)	109,565,996	109,535,037	109,504,912	109,517,299