Earnings (Loss) Per Share (Schedule of Earnings (Loss) Per Share) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations		$ 1,212	$ 856	$ 902
Earnings (loss) from discontinued operations		(5)	(13)	(2)
Net earnings (loss) attributable to Celanese Corporation		$ 1,207	$ 843	$ 900
Weighted average shares - basic		134,305,269	137,902,667	144,939,433
Incremental shares attributable to equity awards	[1]	1,111,589	414,728	728,748
Weighted average shares - diluted		135,416,858	138,317,395	145,668,181
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		0	29	836

[1] Excludes 0, 29 and 836 equity award shares for the years ended December 31, 2018, 2017 and 2016, respectively, as their effect would have been antidilutive.