Unaudited Interim Consolidated Statement Equity - 3 months ended Mar. 31, 2017 - 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, 2016		140,660,447	26,950,910
Balance as of the beginning of the period at Dec. 31, 2016	$ 3,021
Total Celanese Corporation stockholders' equity at Dec. 31, 2016	$ 2,588	$ 0	$ (1,531)	$ 157	$ 4,320	$ (358)
Stock option exercises, shares		12,500
Stock option exercises, net of tax		$ 0		0
Purchases of treasury stock, shares		(1,461,966)
Purchases of treasury stock, including related fees		$ 0
Stock awards, shares		341,572
Stock awards		$ 0
Purchases of treasury stock, shares	1,461,966		1,461,966
Purchases of treasury stock, including related fees	$ (131)		$ (131)
Stock-based compensation, net of tax				(8)
Cumulative effect adjustment from adoption of new accounting standard (Note 2)					(1)
Net earnings (loss) attributable to Celanese Corporation	183				183
Series A common stock dividends					(51)
Other comprehensive income (loss), net of tax	31					31
Balance as of the end of the period, shares at Mar. 31, 2017		139,552,553	28,412,876
Stockholders' Equity Attributable to Noncontrolling Interest at Dec. 31, 2016	433						$ 433
Net earnings (loss) attributable to noncontrolling interests	1						1
(Distributions to) contributions from noncontrolling interests							(4)
Stockholders' Equity Attributable to Noncontrolling Interest at Mar. 31, 2017	430						$ 430
Total Celanese Corporation stockholders' equity at Mar. 31, 2017	2,611	$ 0	$ (1,662)	$ 149	$ 4,451	$ (327)
Balance as of the end of the period at Mar. 31, 2017	$ 3,041