Earnings (Loss) Per Share - Schedule of Earnings (Loss) Per Share (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations		$ 156	$ 219	$ 277	$ 313
Earnings (loss) from discontinued operations		(1)	1	(1)	(2)
Net earnings (loss)		$ 155	$ 220	$ 276	$ 311
Weighted average shares - basic (in shares)		109,314,411	108,886,678	109,191,736	108,761,071
Incremental shares attributable to equity awards(1)	[1]	232,990	419,653	331,628	520,293
Weighted average shares - diluted		109,547,401	109,306,331	109,523,364	109,281,364

[1] Excludes stock options to purchase 187,274 and 242,421 shares of Common Stock for the three months ended June 30, 2024 and 2023, respectively; and 0 and 102,773 equity award shares for the three months ended June 30, 2024 and 2023, respectively, as their effect would have been antidilutive. Excludes stock options to purchase 127,845 and 164,739 shares of Common Stock for the six months ended June 30, 2024 and 2023, respectively; and 0 and 46,008 equity award shares for the six months ended June 30, 2024 and 2023, respectively, as their effect would have been antidilutive.