Earnings (Loss) Per Share (Schedule of Earnings (Loss) Per Share) (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Earnings Per Share [Abstract]
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	$ 606	$ 426	$ 494
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations	606	426	494
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	1	(49)	4
Earnings (loss) from discontinued operations	1	(49)	4
Net earnings (loss)	607	377	498
Cumulative preferred stock dividends	0	(3)	(10)
Net earnings (loss) available to common stockholders	607	374	488
Net earnings (loss) available to common stockholders, diluted	$ 607	$ 377	$ 498
Weighted average shares - basic	156,204,077	154,564,136	143,688,749
Dilutive stock options	1,930,072	1,828,746	1,167,922
Dilutive restricted stock units	813,685	425,385	172,246
Assumed conversion of preferred stock	0	1,553,925	12,086,604
Weighted-average shares - diluted	158,947,834	158,372,192	157,115,521
Per share
Earnings (loss) from continuing operations - basic	$ 3.88	$ 2.73	$ 3.37
Earnings (loss) from discontinued operations - basic	$ 0.01	$ (0.31)	$ 0.03
Net earnings (loss) - basic	$ 3.89	$ 2.42	$ 3.40
Earnings (loss) from continuing operations - diluted	$ 3.81	$ 2.69	$ 3.14
Earnings (loss) from discontinued operations - diluted	$ 0.01	$ (0.31)	$ 0.03
Net earnings (loss) - diluted	$ 3.82	$ 2.38	$ 3.17