Earnings (Loss) Per Share (Schedule of Earnings (Loss) Per Share) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations	$ 207	$ 259	$ 443	$ 455
Earnings (loss) from discontinued operations	(2)	0	(2)	0
Net earnings (loss)	$ 205	$ 259	$ 441	$ 455
Weighted average shares - basic	153,480,175	155,751,779	153,349,071	156,124,714
Incremental shares attributable to equity awards	510,758	302,453	596,395	299,951
Weighted average shares - diluted	153,990,933	156,054,232	153,945,466	156,424,665