Consolidating Guarantor Financial Information (Schedule of Consolidating Statements of Comprehensive Income (Loss) (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 earnings (loss)	$ 233	$ 223	$ 417	$ 482
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	1	0	1	1
Foreign currency translation	78	(18)	106	46
Gain (loss) on cash flow hedges	1	1	(1)	1
Pension and postretirement benefits	0	(1)	5	(1)
Total other comprehensive income (loss), net of tax	80	(18)	111	47
Total comprehensive income (loss), net of tax	313	205	528	529
Comprehensive (income) loss attributable to noncontrolling interests	(2)	(2)	(3)	(4)
Comprehensive income (loss) attributable to Celanese Corporation	311	203	525	525
Parent Guarantor [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	231	222	414	478
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	1	0	1	1
Foreign currency translation	78	(18)	106	46
Gain (loss) on cash flow hedges	1	1	(1)	1
Pension and postretirement benefits	0	(1)	5	(1)
Total other comprehensive income (loss), net of tax	80	(18)	111	47
Total comprehensive income (loss), net of tax	311	204	525	525
Comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Comprehensive income (loss) attributable to Celanese Corporation	311	204	525	525
Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	231	222	414	478
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	1	0	1	1
Foreign currency translation	78	(18)	106	46
Gain (loss) on cash flow hedges	1	1	(1)	1
Pension and postretirement benefits	0	(1)	5	(1)
Total other comprehensive income (loss), net of tax	80	(18)	111	47
Total comprehensive income (loss), net of tax	311	204	525	525
Comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Comprehensive income (loss) attributable to Celanese Corporation	311	204	525	525
Subsidiary Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	202	189	332	431
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	1	0	1	0
Foreign currency translation	96	(18)	126	36
Gain (loss) on cash flow hedges	1	1	(1)	1
Pension and postretirement benefits	0	(1)	4	(1)
Total other comprehensive income (loss), net of tax	98	(18)	130	36
Total comprehensive income (loss), net of tax	300	171	462	467
Comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Comprehensive income (loss) attributable to Celanese Corporation	300	171	462	467
Non-Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	185	153	335	359
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	1	0	1	1
Foreign currency translation	119	(24)	158	58
Gain (loss) on cash flow hedges	1	1	(1)	1
Pension and postretirement benefits	0	0	6	1
Total other comprehensive income (loss), net of tax	121	(23)	164	61
Total comprehensive income (loss), net of tax	306	130	499	420
Comprehensive (income) loss attributable to noncontrolling interests	(2)	(2)	(3)	(4)
Comprehensive income (loss) attributable to Celanese Corporation	304	128	496	416
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	(616)	(563)	(1,078)	(1,264)
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	(3)	0	(3)	(2)
Foreign currency translation	(293)	60	(390)	(140)
Gain (loss) on cash flow hedges	(3)	(3)	3	(3)
Pension and postretirement benefits	0	2	(15)	1
Total other comprehensive income (loss), net of tax	(299)	59	(405)	(144)
Total comprehensive income (loss), net of tax	(915)	(504)	(1,483)	(1,408)
Comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Comprehensive income (loss) attributable to Celanese Corporation	$ (915)	$ (504)	$ (1,483)	$ (1,408)