Earnings (Loss) Per Share (Schedule of Earnings (Loss) Per Share) (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations	$ 183	$ 138
Earnings (loss) from discontinued operations	0	4
Net earnings (loss)	183	142
Cumulative preferred stock dividends	0	0
Net earnings (loss) available to common stockholders	183	142
Net earnings (loss) available to common stockholders, diluted	$ 183	$ 142
Weighted average shares - basic	156,542,424	155,966,259
Dilutive stock options	1,855,015	1,992,598
Dilutive restricted stock units	683,321	707,830
Assumed conversion of preferred stock	0	0
Weighted-average shares - diluted	159,080,760	158,666,687
Per share
Earnings (loss) from continuing operations - basic	$ 1.17	$ 0.88
Earnings (loss) from discontinued operations - basic	$ 0.00	$ 0.03
Net earnings (loss) - basic	$ 1.17	$ 0.91
Earnings (loss) from continuing operations - diluted	$ 1.15	$ 0.87
Earnings (loss) from discontinued operations - diluted	$ 0.00	$ 0.03
Net earnings (loss) - diluted	$ 1.15	$ 0.90