Earnings (Loss) Per Share (Schedule of Earnings (Loss) Per Share) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
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
Weighted average shares - basic (in shares)		109,530,303	109,273,779	108,848,962
Incremental shares attributable to equity awards	[1]	0	0	530,702
Weighted average shares - diluted		109,530,303	109,273,779	109,379,664
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		212,781	239,886
Share-based Payment Arrangement, Option [Member]
Amounts attributable to Celanese Corporation
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		682,886	265,922	202,876
Time Restricted Stock Units (RSUs) [Member]
Amounts attributable to Celanese Corporation
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		68,163	61	39,465

[1] Excludes anti-dilutive incremental shares attributable to equity awards as follows: Year Ended December 31,202520242023(In shares )Options to purchase shares of Common Stock682,886 265,922 202,876 Equity award shares68,163 61 39,465  In addition, the Company incurred a net loss from continuing operations for the years ended December 31, 2025 and 2024, resulting in 212,781 and 239,886, respectively, incremental shares attributable to equity awards being excluded from the number of weighted average shares - diluted as their effect would be antidilutive.