Earnings (Loss) Per Share (Schedule of Earnings (Loss) Per Share) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations	$ 161	$ 258	$ 604	$ 713
Earnings (loss) from discontinued operations	0	(5)	(2)	(5)
Net earnings (loss)	$ 161	$ 253	$ 602	$ 708
Weighted average shares - basic	149,800,029	154,427,554	152,153,057	155,552,777
Incremental shares attributable to equity awards	1,204,052	746,974	1,267,392	772,734
Weighted average shares - diluted	151,004,081	155,174,528	153,420,449	156,325,511