Earnings (Loss) Per Share - Schedule of Earnings (Loss) Per Share (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations		$ 192	$ 519	$ 1,134	$ 1,384
Earnings (loss) from discontinued operations		(1)	(13)	(7)	(18)
Net earnings (loss)		$ 191	$ 506	$ 1,127	$ 1,366
Weighted average shares - basic (in shares)		108,428,982	110,532,051	108,336,574	112,101,651
Incremental shares attributable to equity awards(1)	[1]	636,988	512,507	822,258	597,646
Weighted average shares - diluted		109,065,970	111,044,558	109,158,832	112,699,297

[1] Excludes 181,027 and 0 equity award shares for the three months ended September 30, 2022 and 2021, respectfully, as their effect would have been antidilutive. Excludes 149,272 and 67 equity award shares for the nine months ended September 30, 2022 and 2021, respectfully, as their effect would have been antidilutive.