Earnings (Loss) Per Share - Schedule of Earnings (Loss) Per Share (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations		$ 219	$ 440	$ 313	$ 942
Earnings (loss) from discontinued operations		1	(6)	(2)	(6)
Net earnings (loss)		$ 220	$ 434	$ 311	$ 936
Weighted average shares - basic (in shares)		108,886,678	108,392,155	108,761,071	108,289,603
Incremental shares attributable to equity awards(1)	[1]	419,653	731,194	520,293	868,452
Weighted average shares - diluted		109,306,331	109,123,349	109,281,364	109,158,055

[1] Excludes options to purchase 242,421 and 0 shares of Common Stock for the three months ended June 30, 2023 and 2022, respectively, and 164,739 and 0 shares of Common Stock for the six months ended June 30, 2023 and 2022, respectively, as their effect would have been antidilutive. Excludes 102,773 and 107,287 equity award shares for the three months ended June 30, 2023 and 2022, respectively, and 46,008 and 82,887 equity award shares for the six months ended June 30, 2023 and 2022, respectively, as their effect would have been antidilutive.