Earnings (Loss) Per Share (Schedule of Earnings (Loss) Per Share) (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations	$ 210	$ 205	$ 393	$ 343
Earnings (loss) from discontinued operations	0	(2)	0	2
Net earnings (loss)	210	203	393	345
Cumulative preferred stock dividends	0	0	0	0
Net earnings (loss) available to common stockholders	210	203	393	345
Net earnings (loss) available to common stockholders, diluted	$ 210	$ 203	$ 393	$ 345
Weighted average shares - basic	158,128,906	156,280,721	157,335,665	156,124,358
Dilutive stock options	1,014,359	2,036,940	1,434,687	2,014,769
Dilutive restricted stock units	597,188	891,739	640,255	799,784
Assumed conversion of preferred stock	0	0	0	0
Weighted-average shares - diluted	159,740,453	159,209,400	159,410,607	158,938,911
Per share
Earnings (loss) from continuing operations - basic	$ 1.33	$ 1.31	$ 2.50	$ 2.20
Earnings (loss) from discontinued operations - basic	$ 0.00	$ (0.01)	$ 0.00	$ 0.01
Net earnings (loss) - basic	$ 1.33	$ 1.30	$ 2.50	$ 2.21
Earnings (loss) from continuing operations - diluted	$ 1.31	$ 1.29	$ 2.47	$ 2.16
Earnings (loss) from discontinued operations - diluted	$ 0.00	$ (0.01)	$ 0.00	$ 0.01
Net earnings (loss) - diluted	$ 1.31	$ 1.28	$ 2.47	$ 2.17