Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Net sales	$ 5,655	$ 6,297	$ 7,155
Cost of sales	(4,362)	(4,691)	(5,183)
Gross profit	1,293	1,606	1,972
Selling, general and administrative expenses	(482)	(483)	(546)
Amortization of intangible assets	(22)	(24)	(24)
Research and development expenses	(74)	(67)	(72)
Other (charges) gains, net	(39)	(203)	9
Foreign exchange gain (loss), net	(5)	7	0
Gain (loss) on disposition of businesses and assets, net	(7)	(2)	(5)
Operating profit (loss)	664	834	1,334
Equity in net earnings (loss) of affiliates	134	182	233
Non-operating pension and other postretirement employee benefit (expense) income	17	(20)	(62)
Interest expense	(109)	(115)	(125)
Refinancing expense	0	(4)	(1)
Interest income	6	6	6
Dividend income - equity investments	126	113	117
Gain (loss) on sale of investments in affiliates	1,408	0	0
Other income (expense), net	5	(8)	8
Earnings (loss) from continuing operations before tax	2,251	988	1,510
Income tax (provision) benefit	(247)	(124)	(292)
Earnings (loss) from continuing operations	2,004	864	1,218
Earnings (loss) from operation of discontinued operations	(14)	(8)	(5)
Income tax (provision) benefit from discontinued operations	2	2	0
Earnings (loss) from discontinued operations	(12)	(6)	(5)
Net earnings (loss)	1,992	858	1,213
Net (earnings) loss attributable to noncontrolling interests	(7)	(6)	(6)
Net earnings (loss) attributable to Celanese Corporation	1,985	852	1,207
Amounts attributable to Celanese Corporation
Earnings (loss) from continuing operations	1,997	858	1,212
Earnings (loss) from discontinued operations	(12)	(6)	(5)
Net earnings (loss) attributable to Celanese Corporation	$ 1,985	$ 852	$ 1,207
Earnings (loss) per common share - basic
Continuing operations	$ 16.95	$ 6.93	$ 9.03
Discontinued operations	(0.10)	(0.05)	(0.04)
Net earnings (loss) - basic	16.85	6.88	8.99
Earnings (loss) per common share - diluted
Continuing operations	16.85	6.89	8.95
Discontinued operations	(0.10)	(0.05)	(0.04)
Net earnings (loss) - diluted	$ 16.75	$ 6.84	$ 8.91
Weighted average shares - basic	117,817,445	123,925,697	134,305,269
Weighted average shares - diluted	118,481,376	124,651,759	135,416,858