Earnings (Loss) Per Share (Schedule of Earnings (Loss) Per Share) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations		$ 440	$ 542	$ 942	$ 865
Earnings (loss) from discontinued operations		(6)	(4)	(6)	(5)
Net earnings (loss)		$ 434	$ 538	$ 936	$ 860
Weighted average shares - basic		108,392,155	112,294,274	108,289,603	112,899,459
Incremental shares attributable to equity awards(1)	[1]	731,194	464,365	868,452	571,122
Weighted average shares - diluted		109,123,349	112,758,639	109,158,055	113,470,581

[1] Excludes 107,287 and 82,887 equity award shares for the three and six months ended June 30, 2022, respectively, as their effect would have been antidilutive. There were no antidilutive equity award shares excluded for the three and six months ended June 30, 2021.