Unaudited Interim Consolidated Statement Equity - 9 months ended Sep. 30, 2015 - USD ($) $ in Millions	Total		Series A Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]
Balance as of the beginning of the period, shares at Dec. 31, 2014			152,902,710	13,266,625
Balance as of the beginning of the period at Dec. 31, 2014	$ 3,078
Total Celanese Corporation stockholders' equity at Dec. 31, 2014	2,818		$ 0	$ (611)	$ 103	$ 3,491	$ (165)
Stockholders' Equity Attributable to Noncontrolling Interest at Dec. 31, 2014	$ 260							$ 260
Stock option exercises, shares			70,117
Stock option exercises, net of tax			$ 0		2
Purchases of treasury stock, shares			(6,649,865)
Purchases of treasury stock, including related fees			$ 0
Stock awards, shares			380,629
Stock awards			$ 0
Purchases of treasury stock, shares	6,640,601	[1]		6,649,865
Purchases of treasury stock, including related fees	$ (420)			$ (420)
Stock-based compensation, net of tax					22
Net earnings (loss) attributable to Celanese Corporation	602					602
Series A common stock dividends						(131)
Other comprehensive income (loss), net of tax	(127)						(127)
Net earnings (loss) attributable to noncontrolling interests	(16)							(16)
Contributions from noncontrolling interests								187
Balance as of the end of the period, shares at Sep. 30, 2015			146,703,591	19,916,490
Stockholders' Equity Attributable to Noncontrolling Interest at Sep. 30, 2015	431							$ 431
Total Celanese Corporation stockholders' equity at Sep. 30, 2015	2,766		$ 0	$ (1,031)	$ 127	$ 3,962	$ (292)
Balance as of the end of the period at Sep. 30, 2015	$ 3,197

[1] Excludes 9,264 shares withheld from an executive officer to cover statutory minimum withholding requirements for personal income taxes related to the vesting of restricted stock. Restricted stock awards are considered outstanding at the time of issuance. Accordingly, the shares withheld are treated as treasury shares.