Consolidating Guarantor Financial Information (Schedule of Consolidating Statement of Operations) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Condensed Financial Statements, Captions [Line Items]
Net sales	$ 1,510	$ 1,351	$ 2,981	$ 2,755
Cost of sales	(1,143)	(1,013)	(2,262)	(2,027)
Gross profit	367	338	719	728
Selling, general and administrative expenses	(96)	(71)	(179)	(151)
Amortization of intangible assets	(5)	(2)	(9)	(4)
Research and development expenses	(17)	(19)	(34)	(38)
Other (charges) gains, net	(3)	(4)	(58)	(9)
Foreign exchange gain (loss), net	(4)	(1)	(4)	2
Gain (loss) on disposition of businesses and assets, net	(2)	2	(3)	2
Operating profit (loss)	240	243	432	530
Equity in net earnings (loss) of affiliates	38	35	85	73
Interest expense	(30)	(30)	(59)	(63)
Refinancing expense	0	0	0	(2)
Interest income	1	0	1	1
Dividend income - cost investments	29	29	58	56
Other income (expense), net	3	(2)	4	(2)
Earnings (loss) from continuing operations before tax	281	275	521	593
Income tax (provision) benefit	(40)	(52)	(96)	(112)
Earnings (loss) from continuing operations	241	223	425	481
Earnings (loss) from operation of discontinued operations	(9)	0	(9)	1
Income tax (provision) benefit from discontinued operations	1	0	1	0
Earnings (loss) from discontinued operations	(8)	0	(8)	1
Net earnings (loss)	233	223	417	482
Net (earnings) loss attributable to noncontrolling interests	(2)	(2)	(3)	(4)
Net earnings (loss) attributable to Celanese Corporation	231	221	414	478
Parent Guarantor [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales	0	0	0	0
Cost of sales	0	0	0	0
Gross profit	0	0	0	0
Selling, general and administrative expenses	0	0	0	0
Amortization of intangible assets	0	0	0	0
Research and development expenses	0	0	0	0
Other (charges) gains, net	0	0	0	0
Foreign exchange gain (loss), net	0	0	0	0
Gain (loss) on disposition of businesses and assets, net	0	0	0	0
Operating profit (loss)	0	0	0	0
Equity in net earnings (loss) of affiliates	231	222	414	478
Interest expense	0	0	0	0
Refinancing expense	0	0	0	0
Interest income	0	0	0	0
Dividend income - cost investments	0	0	0	0
Other income (expense), net	0	0	0	0
Earnings (loss) from continuing operations before tax	231	222	414	478
Income tax (provision) benefit	0	0	0	0
Earnings (loss) from continuing operations	231	222	414	478
Earnings (loss) from operation of discontinued operations	0	0	0	0
Income tax (provision) benefit from discontinued operations	0	0	0	0
Earnings (loss) from discontinued operations	0	0	0	0
Net earnings (loss)	231	222	414	478
Net (earnings) loss attributable to noncontrolling interests	0	0	0	0
Net earnings (loss) attributable to Celanese Corporation	231	222	414	478
Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales	0	0	0	0
Cost of sales	0	0	0	0
Gross profit	0	0	0	0
Selling, general and administrative expenses	0	0	0	0
Amortization of intangible assets	0	0	0	0
Research and development expenses	0	0	0	0
Other (charges) gains, net	0	0	0	0
Foreign exchange gain (loss), net	0	0	0	0
Gain (loss) on disposition of businesses and assets, net	0	0	0	0
Operating profit (loss)	0	0	0	0
Equity in net earnings (loss) of affiliates	233	218	407	492
Interest expense	(6)	9	(12)	(6)
Refinancing expense	0	0	0	0
Interest income	6	2	12	4
Dividend income - cost investments	0	0	0	0
Other income (expense), net	(1)	(1)	(1)	(1)
Earnings (loss) from continuing operations before tax	232	228	406	489
Income tax (provision) benefit	(1)	(6)	8	(11)
Earnings (loss) from continuing operations	231	222	414	478
Earnings (loss) from operation of discontinued operations	0	0	0	0
Income tax (provision) benefit from discontinued operations	0	0	0	0
Earnings (loss) from discontinued operations	0	0	0	0
Net earnings (loss)	231	222	414	478
Net (earnings) loss attributable to noncontrolling interests	0	0	0	0
Net earnings (loss) attributable to Celanese Corporation	231	222	414	478
Subsidiary Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales	563	536	1,152	1,119
Cost of sales	(457)	(415)	(900)	(856)
Gross profit	106	121	252	263
Selling, general and administrative expenses	(26)	(5)	(42)	(22)
Amortization of intangible assets	(1)	(1)	(2)	(2)
Research and development expenses	(7)	(8)	(14)	(16)
Other (charges) gains, net	(1)	(1)	(7)	(1)
Foreign exchange gain (loss), net	0	0	0	0
Gain (loss) on disposition of businesses and assets, net	(2)	(2)	(4)	(3)
Operating profit (loss)	69	104	183	219
Equity in net earnings (loss) of affiliates	163	130	264	303
Interest expense	(24)	(36)	(47)	(51)
Refinancing expense	0	0	0	(2)
Interest income	1	1	2	2
Dividend income - cost investments	0	0	0	0
Other income (expense), net	1	0	1	0
Earnings (loss) from continuing operations before tax	210	199	403	471
Income tax (provision) benefit	(8)	(10)	(71)	(40)
Earnings (loss) from continuing operations	202	189	332	431
Earnings (loss) from operation of discontinued operations	0	0	0	0
Income tax (provision) benefit from discontinued operations	0	0	0	0
Earnings (loss) from discontinued operations	0	0	0	0
Net earnings (loss)	202	189	332	431
Net (earnings) loss attributable to noncontrolling interests	0	0	0	0
Net earnings (loss) attributable to Celanese Corporation	202	189	332	431
Non-Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales	1,222	1,073	2,399	2,212
Cost of sales	(966)	(865)	(1,932)	(1,756)
Gross profit	256	208	467	456
Selling, general and administrative expenses	(70)	(66)	(137)	(129)
Amortization of intangible assets	(4)	(1)	(7)	(2)
Research and development expenses	(10)	(11)	(20)	(22)
Other (charges) gains, net	(2)	(3)	(51)	(8)
Foreign exchange gain (loss), net	(4)	(1)	(4)	2
Gain (loss) on disposition of businesses and assets, net	0	4	1	5
Operating profit (loss)	166	130	249	302
Equity in net earnings (loss) of affiliates	34	34	77	71
Interest expense	(8)	(6)	(15)	(14)
Refinancing expense	0	0	0	0
Interest income	2	1	2	3
Dividend income - cost investments	30	29	59	56
Other income (expense), net	3	(1)	4	(1)
Earnings (loss) from continuing operations before tax	227	187	376	417
Income tax (provision) benefit	(34)	(34)	(33)	(59)
Earnings (loss) from continuing operations	193	153	343	358
Earnings (loss) from operation of discontinued operations	(9)	0	(9)	1
Income tax (provision) benefit from discontinued operations	1	0	1	0
Earnings (loss) from discontinued operations	(8)	0	(8)	1
Net earnings (loss)	185	153	335	359
Net (earnings) loss attributable to noncontrolling interests	(2)	(2)	(3)	(4)
Net earnings (loss) attributable to Celanese Corporation	183	151	332	355
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales	(275)	(258)	(570)	(576)
Cost of sales	280	267	570	585
Gross profit	5	9	0	9
Selling, general and administrative expenses	0	0	0	0
Amortization of intangible assets	0	0	0	0
Research and development expenses	0	0	0	0
Other (charges) gains, net	0	0	0	0
Foreign exchange gain (loss), net	0	0	0	0
Gain (loss) on disposition of businesses and assets, net	0	0	0	0
Operating profit (loss)	5	9	0	9
Equity in net earnings (loss) of affiliates	(623)	(569)	(1,077)	(1,271)
Interest expense	8	3	15	8
Refinancing expense	0	0	0	0
Interest income	(8)	(4)	(15)	(8)
Dividend income - cost investments	(1)	0	(1)	0
Other income (expense), net	0	0	0	0
Earnings (loss) from continuing operations before tax	(619)	(561)	(1,078)	(1,262)
Income tax (provision) benefit	3	(2)	0	(2)
Earnings (loss) from continuing operations	(616)	(563)	(1,078)	(1,264)
Earnings (loss) from operation of discontinued operations	0	0	0	0
Income tax (provision) benefit from discontinued operations	0	0	0	0
Earnings (loss) from discontinued operations	0	0	0	0
Net earnings (loss)	(616)	(563)	(1,078)	(1,264)
Net (earnings) loss attributable to noncontrolling interests	0	0	0	0
Net earnings (loss) attributable to Celanese Corporation	$ (616)	$ (563)	$ (1,078)	$ (1,264)