Earnings (Loss) Per Share (Schedule of Earnings (Loss) Per Share) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations		$ 225	$ 338
Earnings (loss) from discontinued operations		(7)	(1)
Net earnings (loss)		$ 218	$ 337
Weighted average shares - basic		119,251,689	127,542,328
Incremental shares attributable to equity awards(1)	[1]	648,155	673,372
Weighted average shares - diluted		119,899,844	128,215,700

[1] Excludes 63,384 and 0 equity awards shares for the three months ended March 31, 2020 and 2019, respectively, as their effect would have been antidilutive.