Unaudited Interim Consolidated Statement Equity - 9 months ended Sep. 30, 2016 - 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, 2015		146,782,297	19,916,490
Balance as of the beginning of the period at Dec. 31, 2015	$ 2,829
Total Celanese Corporation stockholders' equity at Dec. 31, 2015	$ 2,378	$ 0	$ (1,031)	$ 136	$ 3,621	$ (348)
Stock option exercises, shares		93,520
Stock option exercises, net of tax		$ 0		3
Purchases of treasury stock, shares		(4,360,617)
Purchases of treasury stock, including related fees		$ 0
Stock awards, shares		684,295
Stock awards		$ 0
Purchases of treasury stock, shares	4,360,617		4,360,617
Purchases of treasury stock, including related fees	$ (300)		$ (300)
Stock-based compensation, net of tax				1
Net earnings (loss) attributable to Celanese Corporation	740				740
Series A common stock dividends					(150)
Other comprehensive income (loss), net of tax	38					38
Balance as of the end of the period, shares at Sep. 30, 2016		143,199,495	24,277,107
Stockholders' Equity Attributable to Noncontrolling Interest at Dec. 31, 2015	451						$ 451
Net earnings (loss) attributable to noncontrolling interests	5						5
(Distributions to) contributions from noncontrolling interests							(15)
Stockholders' Equity Attributable to Noncontrolling Interest at Sep. 30, 2016	441						$ 441
Total Celanese Corporation stockholders' equity at Sep. 30, 2016	2,710	$ 0	$ (1,331)	$ 140	$ 4,211	$ (310)
Balance as of the end of the period at Sep. 30, 2016	$ 3,151