Consolidating Guarantor Financial Information (Schedule of Consolidating Statements of Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	$ 201	$ 258	$ 435	$ 453
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	(1)	0	(1)	0
Foreign currency translation	37	(22)	(119)	(17)
Gain (loss) on cash flow hedges	1	(3)	3	(6)
Pension and postretirement benefits	4	(14)	1	(26)
Total other comprehensive income (loss), net of tax	41	(39)	(116)	(49)
Total comprehensive income (loss), net of tax	242	219	319	404
Comprehensive (income) loss attributable to noncontrolling interests	4	1	6	2
Comprehensive income (loss) attributable to Celanese Corporation	246	220	325	406
Parent Guarantor [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	205	259	441	455
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	(1)	0	(1)	0
Foreign currency translation	37	(22)	(119)	(17)
Gain (loss) on cash flow hedges	1	(3)	3	(6)
Pension and postretirement benefits	4	(14)	1	(26)
Total other comprehensive income (loss), net of tax	41	(39)	(116)	(49)
Total comprehensive income (loss), net of tax	246	220	325	406
Comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Comprehensive income (loss) attributable to Celanese Corporation	246	220	325	406
Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	206	259	441	454
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	(1)	0	(1)	0
Foreign currency translation	37	(22)	(119)	(17)
Gain (loss) on cash flow hedges	1	(3)	3	(6)
Pension and postretirement benefits	4	(14)	1	(26)
Total other comprehensive income (loss), net of tax	41	(39)	(116)	(49)
Total comprehensive income (loss), net of tax	247	220	325	405
Comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Comprehensive income (loss) attributable to Celanese Corporation	247	220	325	405
Subsidiary Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	215	152	455	345
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	(1)	0	(1)	0
Foreign currency translation	56	(9)	(114)	7
Gain (loss) on cash flow hedges	1	0	6	0
Pension and postretirement benefits	3	(14)	0	(26)
Total other comprehensive income (loss), net of tax	59	(23)	(109)	(19)
Total comprehensive income (loss), net of tax	274	129	346	326
Comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Comprehensive income (loss) attributable to Celanese Corporation	274	129	346	326
Non-Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	123	148	240	222
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	(1)	0	(1)	0
Foreign currency translation	74	2	(137)	(14)
Gain (loss) on cash flow hedges	1	(3)	3	(3)
Pension and postretirement benefits	4	0	4	0
Total other comprehensive income (loss), net of tax	78	(1)	(131)	(17)
Total comprehensive income (loss), net of tax	201	147	109	205
Comprehensive (income) loss attributable to noncontrolling interests	4	1	6	2
Comprehensive income (loss) attributable to Celanese Corporation	205	148	115	207
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	(548)	(560)	(1,142)	(1,023)
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	3	0	3	0
Foreign currency translation	(167)	29	370	24
Gain (loss) on cash flow hedges	(3)	6	(12)	9
Pension and postretirement benefits	(11)	28	(5)	52
Total other comprehensive income (loss), net of tax	(178)	63	356	85
Total comprehensive income (loss), net of tax	(726)	(497)	(786)	(938)
Comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Comprehensive income (loss) attributable to Celanese Corporation	$ (726)	$ (497)	$ (786)	$ (938)