Unaudited Interim Consolidated Statement of Operations - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Income Statement [Abstract]
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 of intangible assets	(40)	(40)
Research and development expenses	(28)	(31)
Other (charges) gains, net	(20)	(31)
Foreign exchange gain (loss), net	12	21
Gain (loss) on disposition of business and assets, net	48	3
Operating profit (loss)	214	165
Equity in net earnings (loss) of affiliates	35	22
Non-operating pension and other postretirement employee benefit (expense) income	5	2
Interest expense	(183)	(170)
Refinancing expense	0	32
Interest income	9	4
Dividend income - equity investments	1	1
Other income (expense), net	1	2
Earnings (loss) from continuing operations before tax	82	(6)
Income tax (provision) benefit	(33)	(9)
Earnings (loss) from continuing operations	49	(15)
Earnings (loss) from operation of discontinued operations	(1)	(6)
Income tax (provision) benefit from discontinued operations	0	1
Earnings (loss) from discontinued operations	(1)	(5)
Net earnings (loss)	48	(20)
Net (earnings) loss attributable to noncontrolling interests	(4)	(4)
Net earnings (loss) attributable to Celanese Corporation	44	(24)
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations	45	(19)
Earnings (loss) from discontinued operations	(1)	(5)
Net earnings (loss)	$ 44	$ (24)
Earnings (loss) per common share - basic
Continuing operations - basic (in dollars per share)	$ 0.41	$ (0.17)
Discontinued operations - basic (in dollars per share)	(0.01)	(0.05)
Net earnings (loss) - basic (in dollars per share)	0.40	(0.22)
Earnings (loss) per common share - diluted
Continuing operations - diluted (in dollars per share)	0.41	(0.17)
Discontinued operations - diluted (in dollars per share)	(0.01)	(0.05)
Net earnings (loss) - diluted (in dollars per share)	$ 0.40	$ (0.22)
Weighted average shares - basic (in shares)	109,663,939	109,421,035
Weighted average shares - diluted (in shares)	109,978,947	109,421,035