Earnings (Loss) Per Share (Schedule of Earnings (Loss) Per Share) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations		$ 858	$ 1,212	$ 856
Earnings (loss) from discontinued operations		(6)	(5)	(13)
Net earnings (loss) attributable to Celanese Corporation		$ 852	$ 1,207	$ 843
Weighted average shares - basic		123,925,697	134,305,269	137,902,667
Incremental shares attributable to equity awards	[1]	726,062	1,111,589	414,728
Weighted average shares - diluted		124,651,759	135,416,858	138,317,395
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		45	0	29

[1] Excludes 45, 0 and 29 equity award shares for the years ended December 31, 2019, 2018 and 2017, respectively, as their effect would have been antidilutive.