Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common Stock	Treasury Stock, Common	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss), Net	Noncontrolling Interests
Balance as of the beginning of the period (in shares) at Dec. 31, 2022		108,473,932
Balance as of the beginning of the period at Dec. 31, 2022		$ 0	$ (5,491)	$ 372	$ 11,265	$ (518)
Balance as of the beginning of the period (in shares) at Dec. 31, 2022			61,661,493
Stock option exercises (in shares)		968
Stock awards (in shares)		431,526
Stock awards		$ 0
Issuance of treasury stock under stock plans (in shares)			(91,179)
Issuance of treasury stock under stock plans			$ 3
Balance as of the end of the period (in shares) at Dec. 31, 2023		108,906,426
Balance as of the end of the period at Dec. 31, 2023	$ 7,065	$ 0	$ (5,488)	394	12,903	(744)
Balance as of the end of the period (in shares) at Dec. 31, 2023			61,570,314
Stock-based compensation, net of tax				22
Stock option exercises, net of tax		$ 0		0
Net earnings (loss) attributable to Celanese Corporation	1,943				1,943
Common stock dividends					(305)
Other comprehensive income (loss), net of tax	(226)					(226)	$ 0
Balance as of the beginning of the period, noncontrolling interest at Dec. 31, 2022	468
Net earnings (loss) attributable to noncontrolling interests	(4)						(4)
Distributions/dividends to noncontrolling interests							11
Balance as of the end of the period, noncontrolling interest at Dec. 31, 2023	461
Balance as of the end of the period at Dec. 31, 2023	7,526					(744)
Stock option exercises (in shares)		10,088
Stock awards (in shares)		411,042
Stock awards		$ 0
Issuance of treasury stock under stock plans (in shares)			(70,674)
Issuance of treasury stock under stock plans			$ 2
Balance as of the end of the period (in shares) at Dec. 31, 2024		109,327,556
Balance as of the end of the period at Dec. 31, 2024	5,129	$ 0	$ (5,486)	409	11,054	(848)
Balance as of the end of the period (in shares) at Dec. 31, 2024			61,499,640
Stock-based compensation, net of tax				14
Stock option exercises, net of tax		$ 0		1
Net earnings (loss) attributable to Celanese Corporation	(1,542)				(1,542)
Common stock dividends					(307)
Other comprehensive income (loss), net of tax	(106)					(104)	(2)
Net earnings (loss) attributable to noncontrolling interests	(8)						(8)
Distributions/dividends to noncontrolling interests							33
Balance as of the end of the period, noncontrolling interest at Dec. 31, 2024	434
Balance as of the end of the period at Dec. 31, 2024	5,563					(848)
Stock option exercises (in shares)		0
Stock awards (in shares)		242,601
Stock awards		$ 0
Issuance of treasury stock under stock plans (in shares)			(151,576)
Issuance of treasury stock under stock plans			$ 4
Balance as of the end of the period (in shares) at Dec. 31, 2025		109,570,157
Balance as of the end of the period at Dec. 31, 2025	4,049	$ 0	$ (5,482)	431	9,876	(776)
Balance as of the end of the period (in shares) at Dec. 31, 2025			61,348,064
Stock-based compensation, net of tax				22
Stock option exercises, net of tax		$ 0		$ 0
Net earnings (loss) attributable to Celanese Corporation	(1,165)				(1,165)
Common stock dividends					$ (13)
Other comprehensive income (loss), net of tax	77					72	5
Net earnings (loss) attributable to noncontrolling interests	(14)						(14)
Distributions/dividends to noncontrolling interests							$ 30
Balance as of the end of the period, noncontrolling interest at Dec. 31, 2025	423
Balance as of the end of the period at Dec. 31, 2025	$ 4,472					$ (776)