Unaudited Interim Consolidated Statement Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss), Net	Noncontrolling Interests	Treasury Stock, Common
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Celanese Corporation stockholders' equity		$ 0	$ 333	$ 9,677	$ (329)		$ (5,492)
Balance as of the beginning of the period (in shares) at Dec. 31, 2021		108,023,735					61,736,289
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation, net of tax			23
Purchases of treasury stock (in shares)	0
Issuance of treasury stock under stock plans							$ 0
Issuance of treasury stock under stock plans (in shares)							(32,243)
Stock awards (in shares)		363,004
Stock awards		$ 0
Net earnings (loss) attributable to Celanese Corporation	$ 1,127			1,127
Common stock dividends				(220)
Other comprehensive income (loss), net of tax	(169)				(169)
Balance as of the beginning of the period, noncontrolling interest at Dec. 31, 2021						$ 348
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss) attributable to noncontrolling interests	6					6
Distributions/dividends to noncontrolling interests						(10)
Balance as of the end of the period, noncontrolling interest at Sep. 30, 2022						344
Balance as of the end of the period (in shares) at Sep. 30, 2022		108,386,739					61,704,046
Balance as of the end of the period at Sep. 30, 2022	5,294
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Celanese Corporation stockholders' equity		$ 0	344	10,466	(438)		$ (5,492)
Balance as of the beginning of the period (in shares) at Jun. 30, 2022		108,346,035					61,704,046
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation, net of tax			12
Issuance of treasury stock under stock plans							$ 0
Issuance of treasury stock under stock plans (in shares)							0
Stock awards (in shares)		40,704
Stock awards		$ 0
Net earnings (loss) attributable to Celanese Corporation	191			191
Common stock dividends				(73)
Other comprehensive income (loss), net of tax	(60)				(60)
Balance as of the beginning of the period, noncontrolling interest at Jun. 30, 2022						345
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss) attributable to noncontrolling interests	2					2
Distributions/dividends to noncontrolling interests						(3)
Balance as of the end of the period, noncontrolling interest at Sep. 30, 2022						344
Balance as of the end of the period (in shares) at Sep. 30, 2022		108,386,739					61,704,046
Balance as of the end of the period at Sep. 30, 2022	5,294
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Celanese Corporation stockholders' equity	4,950	$ 0	356	10,584	(498)		$ (5,492)
Celanese Corporation stockholders' equity	5,637	$ 0	372	11,274	(518)		$ (5,491)
Balance as of the beginning of the period (in shares) at Dec. 31, 2022		108,473,932					61,661,493
Balance as of the beginning of the period at Dec. 31, 2022	$ 6,105
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation, net of tax			14
Purchases of treasury stock (in shares)	0
Issuance of treasury stock under stock plans							$ 1
Issuance of treasury stock under stock plans (in shares)							(50,092)
Stock awards (in shares)		380,106
Stock awards		$ 0
Net earnings (loss) attributable to Celanese Corporation	$ 1,262			1,262
Common stock dividends				(228)
Other comprehensive income (loss), net of tax	(195)				(195)
Balance as of the beginning of the period, noncontrolling interest at Dec. 31, 2022	468					468
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss) attributable to noncontrolling interests	1					1
Distributions/dividends to noncontrolling interests						(11)
Balance as of the end of the period, noncontrolling interest at Sep. 30, 2023	458					458
Balance as of the end of the period (in shares) at Sep. 30, 2023		108,854,038					61,611,401
Balance as of the end of the period at Sep. 30, 2023	6,949
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Celanese Corporation stockholders' equity		$ 0	383	11,433	(702)		$ (5,490)
Balance as of the beginning of the period (in shares) at Jun. 30, 2023		108,847,435					61,611,401
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation, net of tax			3
Issuance of treasury stock under stock plans							$ 0
Issuance of treasury stock under stock plans (in shares)							0
Stock awards (in shares)		6,603
Stock awards		$ 0
Net earnings (loss) attributable to Celanese Corporation	951			951
Common stock dividends				(76)
Other comprehensive income (loss), net of tax	(11)				(11)
Balance as of the beginning of the period, noncontrolling interest at Jun. 30, 2023						464
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss) attributable to noncontrolling interests	(2)					(2)
Distributions/dividends to noncontrolling interests						(4)
Balance as of the end of the period, noncontrolling interest at Sep. 30, 2023	458					$ 458
Balance as of the end of the period (in shares) at Sep. 30, 2023		108,854,038					61,611,401
Balance as of the end of the period at Sep. 30, 2023	6,949
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Celanese Corporation stockholders' equity	$ 6,491	$ 0	$ 386	$ 12,308	$ (713)		$ (5,490)