Consolidating Guarantor Financial Information (Schedule of Consolidating Statements of Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	$ 228	$ 263	$ 645	$ 745
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	0	(1)	1	0
Foreign currency translation	42	(8)	148	38
Gain (loss) on cash flow hedges	0	0	(1)	1
Pension and postretirement benefits	(1)	0	4	(1)
Total other comprehensive income (loss), net of tax	41	(9)	152	38
Total comprehensive income (loss), net of tax	269	254	797	783
Comprehensive (income) loss attributable to noncontrolling interests	(2)	(1)	(5)	(5)
Comprehensive income (loss) attributable to Celanese Corporation	267	253	792	778
Parent Guarantor [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	226	262	640	740
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	0	(1)	1	0
Foreign currency translation	42	(8)	148	38
Gain (loss) on cash flow hedges	0	0	(1)	1
Pension and postretirement benefits	(1)	0	4	(1)
Total other comprehensive income (loss), net of tax	41	(9)	152	38
Total comprehensive income (loss), net of tax	267	253	792	778
Comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Comprehensive income (loss) attributable to Celanese Corporation	267	253	792	778
Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	226	262	640	740
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	0	(1)	1	0
Foreign currency translation	42	(8)	148	38
Gain (loss) on cash flow hedges	0	0	(1)	1
Pension and postretirement benefits	(1)	0	4	(1)
Total other comprehensive income (loss), net of tax	41	(9)	152	38
Total comprehensive income (loss), net of tax	267	253	792	778
Comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Comprehensive income (loss) attributable to Celanese Corporation	267	253	792	778
Subsidiary Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	154	224	486	655
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	0	0	1	0
Foreign currency translation	65	(8)	191	28
Gain (loss) on cash flow hedges	0	0	(1)	1
Pension and postretirement benefits	(1)	0	3	(1)
Total other comprehensive income (loss), net of tax	64	(8)	194	28
Total comprehensive income (loss), net of tax	218	216	680	683
Comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Comprehensive income (loss) attributable to Celanese Corporation	218	216	680	683
Non-Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	261	193	596	552
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	0	(1)	1	0
Foreign currency translation	74	(4)	232	54
Gain (loss) on cash flow hedges	0	0	(1)	1
Pension and postretirement benefits	0	0	6	1
Total other comprehensive income (loss), net of tax	74	(5)	238	56
Total comprehensive income (loss), net of tax	335	188	834	608
Comprehensive (income) loss attributable to noncontrolling interests	(2)	(1)	(5)	(5)
Comprehensive income (loss) attributable to Celanese Corporation	333	187	829	603
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	(639)	(678)	(1,717)	(1,942)
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	0	2	(3)	0
Foreign currency translation	(181)	20	(571)	(120)
Gain (loss) on cash flow hedges	0	0	3	(3)
Pension and postretirement benefits	2	0	(13)	1
Total other comprehensive income (loss), net of tax	(179)	22	(584)	(122)
Total comprehensive income (loss), net of tax	(818)	(656)	(2,301)	(2,064)
Comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Comprehensive income (loss) attributable to Celanese Corporation	$ (818)	$ (656)	$ (2,301)	$ (2,064)