Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), Net [Member]	Noncontrolling Interests [Member]
Shares, Issued		128,095,849	40,323,105
Balance as of the beginning of the period at Dec. 31, 2018							$ 395
Balance as of the beginning of the year at Dec. 31, 2018		$ 0	$ (2,849)	$ 233	$ 5,847	$ (247)
Stock option exercises, net of tax		$ 0		(1)
Stock option exercises, shares		14,045
Stock awards, shares		611,580
Stock awards		$ 0
Purchases of treasury stock, shares	9,166,267	9,166,267	(9,166,267)
Purchases of treasury stock, including related fees	$ (1,000)	$ 0	$ (1,000)
Stock-based compensation, net of tax			3
Net earnings (loss) attributable to Celanese Corporation	852				852
Common stock dividends					(300)
Other comprehensive income (loss), net of tax	(53)					(53)
Balance as of the end of the year at Dec. 31, 2019	2,507	$ 0	$ (3,846)	254	6,399	(300)
Balance as of the end of the period, shares at Dec. 31, 2019		119,555,207	49,417,965
Net earnings (loss) attributable to noncontrolling interests	(6)						(6)
Balance as of the end of the period at Dec. 31, 2019							391
Total equity at Dec. 31, 2019	$ 2,898
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture			(71,407)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition				22
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders							(10)
Shares, Issued		119,555,207	49,417,965
Stock option exercises, net of tax		$ 0		0
Stock option exercises, shares		0
Stock awards, shares		502,330
Stock awards		$ 0
Purchases of treasury stock, shares	5,889,073	5,889,073	(5,889,073)
Purchases of treasury stock, including related fees	$ (650)	$ 0	$ (650)
Stock-based compensation, net of tax			2
Net earnings (loss) attributable to Celanese Corporation	1,985				1,985
Common stock dividends					(293)
Other comprehensive income (loss), net of tax	(28)					(28)
Balance as of the end of the year at Dec. 31, 2020	3,526	$ 0	$ (4,494)	257	8,091	(328)
Balance as of the end of the period, shares at Dec. 31, 2020		114,168,464	55,234,515
Net earnings (loss) attributable to noncontrolling interests	(7)						(7)
Balance as of the end of the period at Dec. 31, 2020	369						369
Total equity at Dec. 31, 2020	$ 3,895
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture			(72,523)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition				3
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders							(29)
Shares, Issued		114,168,464	55,234,515
Stock option exercises, net of tax		$ 0		0
Stock option exercises, shares		0
Stock awards, shares		411,649
Stock awards		$ 0
Purchases of treasury stock, shares	6,556,378	6,556,378	(6,556,378)
Purchases of treasury stock, including related fees	$ (1,000)	$ 0	$ (1,000)
Stock-based compensation, net of tax			2
Net earnings (loss) attributable to Celanese Corporation	1,890				1,890
Common stock dividends					(304)
Other comprehensive income (loss), net of tax	(1)					(1)
Balance as of the end of the year at Dec. 31, 2021	4,189	$ 0	$ (5,492)	333	$ 9,677	$ (329)
Balance as of the end of the period, shares at Dec. 31, 2021		108,023,735	61,736,289
Net earnings (loss) attributable to noncontrolling interests	(6)						(6)
Balance as of the end of the period at Dec. 31, 2021	348						348
Total equity at Dec. 31, 2021	$ 4,537
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture			(54,604)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition				$ 76
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders							$ (27)