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)		373,503
Stock awards		$ 0
Issuance of treasury stock under stock plans (in shares)			(50,092)
Issuance of treasury stock under stock plans			$ 1
Stock-based compensation, net of tax				11
Net earnings (loss) attributable to Celanese Corporation	$ 311				311
Common stock dividends					(152)
Other comprehensive income (loss), net of tax	(184)					(184)	$ 0
Balance as of the end of the period (in shares) at Jun. 30, 2023		108,847,435	61,611,401
Balance as of the end of the period at Jun. 30, 2023	5,624	$ 0	$ (5,490)	383	11,433	(702)
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	3						3
Distributions/dividends to noncontrolling interests							(7)
Balance as of the end of the period, noncontrolling interest at Jun. 30, 2023							464
Balance as of the beginning of the period (in shares) at Mar. 31, 2023		108,786,738	61,661,493
Balance as of the beginning of the period at Mar. 31, 2023		$ 0	$ (5,491)	365	11,289	(502)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises, shares		0
Stock option exercises		$ 0
Stock awards (in shares)		60,697
Stock awards		$ 0
Issuance of treasury stock under stock plans (in shares)			(50,092)
Issuance of treasury stock under stock plans			$ 1
Stock-based compensation, net of tax				18
Net earnings (loss) attributable to Celanese Corporation	220				220
Common stock dividends					(76)
Other comprehensive income (loss), net of tax	(200)					(200)	0
Balance as of the end of the period (in shares) at Jun. 30, 2023		108,847,435	61,611,401
Balance as of the end of the period at Jun. 30, 2023	5,624	$ 0	$ (5,490)	383	11,433	(702)
Balance as of the beginning of the period, noncontrolling interest at Mar. 31, 2023							469
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss) attributable to noncontrolling interests	1						1
Distributions/dividends to noncontrolling interests							(6)
Balance as of the end of the period, noncontrolling interest at Jun. 30, 2023							464
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity	6,088
Total equity	7,552
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		9,239
Stock option exercises		$ 0		1
Stock awards (in shares)		346,898
Stock awards		$ 0
Issuance of treasury stock under stock plans (in shares)			(33,068)
Issuance of treasury stock under stock plans			$ 1
Stock-based compensation, net of tax				(1)
Net earnings (loss) attributable to Celanese Corporation	276				276
Common stock dividends					(154)
Other comprehensive income (loss), net of tax	(48)					(48)	(1)
Balance as of the end of the period (in shares) at Jun. 30, 2024		109,262,563	61,537,246
Balance as of the end of the period at Jun. 30, 2024	7,166	$ 0	$ (5,487)	394	13,051	(792)
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	1						1
Distributions/dividends to noncontrolling interests							(18)
Balance as of the end of the period, noncontrolling interest at Jun. 30, 2024	443						443
Balance as of the beginning of the period (in shares) at Mar. 31, 2024		109,210,286	61,570,314
Balance as of the beginning of the period at Mar. 31, 2024		$ 0	$ (5,488)	383	12,973	(797)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises, shares		1,292
Stock option exercises		$ 0
Stock awards (in shares)		50,985
Stock awards		$ 0
Issuance of treasury stock under stock plans (in shares)			(33,068)
Issuance of treasury stock under stock plans			$ 1
Stock-based compensation, net of tax				11
Net earnings (loss) attributable to Celanese Corporation	155				155
Common stock dividends					(77)
Other comprehensive income (loss), net of tax	5					5	(1)
Balance as of the end of the period (in shares) at Jun. 30, 2024		109,262,563	61,537,246
Balance as of the end of the period at Jun. 30, 2024	7,166	$ 0	$ (5,487)	$ 394	$ 13,051	$ (792)
Balance as of the beginning of the period, noncontrolling interest at Mar. 31, 2024							460
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss) attributable to noncontrolling interests	(2)						(2)
Distributions/dividends to noncontrolling interests							(14)
Balance as of the end of the period, noncontrolling interest at Jun. 30, 2024	443						$ 443
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity	$ 7,609