Earnings (Loss) Per Share - Schedule of Earnings (Loss) Per Share (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations		$ 952	$ 192	$ 1,265	$ 1,134
Earnings (loss) from discontinued operations		(1)	(1)	(3)	(7)
Net earnings (loss)		$ 951	$ 191	$ 1,262	$ 1,127
Weighted average shares - basic (in shares)		108,918,986	108,428,982	108,814,288	108,336,574
Incremental shares attributable to equity awards(1)	[1]	520,500	636,988	523,752	822,258
Weighted average shares - diluted		109,439,486	109,065,970	109,338,040	109,158,832

[1] Excludes options to purchase 219,963 and 0 shares of Common Stock for the three months ended September 30, 2023 and 2022, respectively, and options to purchase 190,651 and 0 shares of Common Stock for the nine months ended September 30, 2023 and 2022, respectively, as their effect would have been antidilutive. Excludes 0 and 181,027 equity award shares for the three months ended September 30, 2023 and 2022, respectively, and 42,998 and 149,272 equity award shares for the nine months ended September 30, 2023 and 2022, respectively, as their effect would have been antidilutive.