Earnings (Loss) Per Share (Schedule of Earnings (Loss) Per Share) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations	$ 239	$ 221	$ 422	$ 477
Earnings (loss) from discontinued operations	(8)	0	(8)	1
Net earnings (loss)	$ 231	$ 221	$ 414	$ 478
Weighted average shares - basic	138,619,721	146,482,612	139,626,199	146,947,923
Incremental shares attributable to equity awards	409,704	583,076	396,357	644,608
Weighted average shares - diluted	139,029,425	147,065,688	140,022,556	147,592,531