Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Statement [Abstract]
Net sales	$ 9,544	$ 10,268	$ 10,926
Cost of sales	(7,592)	(7,932)	(8,343)
Gross profit	1,952	2,336	2,583
Selling, general and administrative expenses	(899)	(1,033)	(1,077)
Amortization of intangible assets	(164)	(159)	(164)
Research and development expenses	(125)	(130)	(146)
Other (charges) gains, net	(1,581)	(1,744)	(68)
Foreign exchange gain (loss), net	36	24	32
Gain (loss) on disposition of businesses and assets, net	(5)	(14)	505
Operating profit (loss)	(786)	(720)	1,665
Equity in net earnings (loss) of affiliates	127	196	102
Non-operating pension and other postretirement employee benefit (expense) income	55	(20)	(69)
Interest expense	(701)	(676)	(720)
Refinancing expense	(68)	0	(7)
Interest income	24	33	39
Dividend income - equity investments	122	128	126
Other income (expense), net	7	40	25
Earnings (loss) from continuing operations before tax	(1,220)	(1,019)	1,161
Income tax (provision) benefit	90	(507)	795
Earnings (loss) from continuing operations	(1,130)	(1,526)	1,956
Earnings (loss) from operation of discontinued operations	(24)	(10)	(12)
Income tax (provision) benefit from discontinued operations	3	2	3
Earnings (loss) from discontinued operations	(21)	(8)	(9)
Net earnings (loss)	(1,151)	(1,534)	1,947
Net (earnings) loss attributable to noncontrolling interests	(14)	(8)	(4)
Net earnings (loss) attributable to Celanese Corporation	(1,165)	(1,542)	1,943
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations	(1,144)	(1,534)	1,952
Earnings (loss) from discontinued operations	(21)	(8)	(9)
Net earnings (loss) attributable to Celanese Corporation	$ (1,165)	$ (1,542)	$ 1,943
Earnings (loss) per common share - basic
Continuing operations - basic (in dollars per share)	$ (10.44)	$ (14.04)	$ 17.93
Discontinued operations - basic (in dollars per share)	(0.20)	(0.07)	(0.08)
Net earnings (loss) - basic (in dollars per share)	(10.64)	(14.11)	17.85
Earnings (loss) per common share - diluted
Continuing operations - diluted (in dollars per share)	(10.44)	(14.04)	17.84
Discontinued operations - diluted (in dollars per share)	(0.20)	(0.07)	(0.08)
Net earnings (loss) - diluted (in dollars per share)	$ (10.64)	$ (14.11)	$ 17.76
Weighted average shares - basic (in shares)	109,530,303	109,273,779	108,848,962
Weighted average shares - diluted (in shares)	109,530,303	109,273,779	109,379,664