Unaudited Interim Consolidated Statement 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	61,661,493
Balance as of the beginning of the period at Dec. 31, 2022		$ 0	$ (5,491)	$ 372	$ 11,274	$ (518)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises, shares		0
Stock option exercises		$ 0		0
Stock awards (in shares)		312,806
Stock awards		$ 0
Issuance of treasury stock under stock plans (in shares)			0
Issuance of treasury stock under stock plans			$ 0
Stock-based compensation, net of tax				(7)
Net earnings (loss) attributable to Celanese Corporation	$ 91				91
Common stock dividends					(76)
Other comprehensive income (loss), net of tax	16					16
Balance as of the end of the period (in shares) at Mar. 31, 2023		108,786,738	61,661,493
Balance as of the end of the period at Mar. 31, 2023	5,661	$ 0	$ (5,491)	365	11,289	(502)
Balance as of the beginning of the period, noncontrolling interest at Dec. 31, 2022							$ 468
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss) attributable to noncontrolling interests	2						2
Distributions/dividends to noncontrolling interests							(1)
Balance as of the end of the period, noncontrolling interest at Mar. 31, 2023							469
Balance as of the end of the period at Mar. 31, 2023	6,130
Balance as of the beginning of the period (in shares) at Dec. 31, 2023		108,906,426	61,570,314
Balance as of the beginning of the period at Dec. 31, 2023	7,091	$ 0	$ (5,488)	394	12,929	(744)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises, shares		7,947
Stock option exercises		$ 0		1
Stock awards (in shares)		295,913
Stock awards		$ 0
Issuance of treasury stock under stock plans (in shares)			0
Issuance of treasury stock under stock plans			$ 0
Stock-based compensation, net of tax				(12)
Net earnings (loss) attributable to Celanese Corporation	121				121
Common stock dividends					(77)
Other comprehensive income (loss), net of tax	(53)					(53)
Balance as of the end of the period (in shares) at Mar. 31, 2024		109,210,286	61,570,314
Balance as of the end of the period at Mar. 31, 2024	7,071	$ 0	$ (5,488)	$ 383	$ 12,973	$ (797)
Balance as of the beginning of the period, noncontrolling interest at Dec. 31, 2023	461						461
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss) attributable to noncontrolling interests	3						3
Distributions/dividends to noncontrolling interests							(4)
Balance as of the end of the period, noncontrolling interest at Mar. 31, 2024	460						$ 460
Balance as of the end of the period at Mar. 31, 2024	$ 7,531