Earnings (Loss) Per Share (Schedule of Earnings (Loss) Per Share) (Details) (USD $) In Millions, except Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations	$ 205	$ 163	$ 343	$ 176
Earnings (loss) from discontinued operations	(2)	(3)	2	(2)
Net earnings (loss)	203	160	345	174
Cumulative preferred stock dividends	0	0	0	(3)
Net earnings (loss) available to common shareholders	203	160	345	171
Net earnings (loss) available to common shareholders, diluted	$ 203	$ 160	$ 345	$ 174
Weighted average shares - basic	156,280,721	156,326,226	156,124,358	153,315,950
Dilutive stock options	2,036,940	1,787,983	2,014,769	1,854,552
Dilutive restricted stock units	868,416	290,910	788,123	369,966
Assumed conversion of preferred stock	0	0	0	3,133,605
Weighted average shares - diluted	159,186,077	158,405,119	158,927,250	158,674,073
Per share
Earnings (loss) from continuing operations - basic	$ 1.31	$ 1.04	$ 2.20	$ 1.13
Earnings (loss) from discontinued operations - basic	$ (0.01)	$ (0.02)	$ 0.01	$ (0.01)
Net earnings (loss) - basic	$ 1.30	$ 1.02	$ 2.21	$ 1.12
Earnings (loss) from continuing operations - diluted	$ 1.29	$ 1.03	$ 2.16	$ 1.11
Earnings (loss) from discontinued operations - diluted	$ (0.01)	$ (0.02)	$ 0.01	$ (0.01)
Net earnings (loss) - diluted	$ 1.28	$ 1.01	$ 2.17	$ 1.10