Consolidating Guarantor Financial Information (Schedule of Consolidating Statements of Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	$ 151	$ 252	$ 586	$ 705
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	1	0	0	0
Foreign currency translation	(11)	(124)	(130)	(141)
Gain (loss) on cash flow hedges	(1)	(5)	2	(11)
Pension and postretirement benefits	0	(8)	1	(34)
Total other comprehensive income (loss), net of tax	(11)	(137)	(127)	(186)
Total comprehensive income (loss), net of tax	140	115	459	519
Comprehensive (income) loss attributable to noncontrolling interests	10	1	16	3
Comprehensive income (loss) attributable to Celanese Corporation	150	116	475	522
Parent Guarantor [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	161	253	602	708
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	1	0	0	0
Foreign currency translation	(11)	(124)	(130)	(141)
Gain (loss) on cash flow hedges	(1)	(5)	2	(11)
Pension and postretirement benefits	0	(8)	1	(34)
Total other comprehensive income (loss), net of tax	(11)	(137)	(127)	(186)
Total comprehensive income (loss), net of tax	150	116	475	522
Comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Comprehensive income (loss) attributable to Celanese Corporation	150	116	475	522
Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	161	252	602	706
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	1	0	0	0
Foreign currency translation	(11)	(124)	(130)	(141)
Gain (loss) on cash flow hedges	(1)	(5)	2	(11)
Pension and postretirement benefits	0	(8)	1	(34)
Total other comprehensive income (loss), net of tax	(11)	(137)	(127)	(186)
Total comprehensive income (loss), net of tax	150	115	475	520
Comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Comprehensive income (loss) attributable to Celanese Corporation	150	115	475	520
Subsidiary Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	142	218	597	563
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	1	0	0	0
Foreign currency translation	4	(4)	(110)	3
Gain (loss) on cash flow hedges	(1)	0	5	0
Pension and postretirement benefits	0	(8)	0	(34)
Total other comprehensive income (loss), net of tax	4	(12)	(105)	(31)
Total comprehensive income (loss), net of tax	146	206	492	532
Comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Comprehensive income (loss) attributable to Celanese Corporation	146	206	492	532
Non-Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	75	129	315	351
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	1	0	0	0
Foreign currency translation	(7)	(16)	(144)	(30)
Gain (loss) on cash flow hedges	(1)	(6)	2	(9)
Pension and postretirement benefits	0	0	4	0
Total other comprehensive income (loss), net of tax	(7)	(22)	(138)	(39)
Total comprehensive income (loss), net of tax	68	107	177	312
Comprehensive (income) loss attributable to noncontrolling interests	10	1	16	3
Comprehensive income (loss) attributable to Celanese Corporation	78	108	193	315
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	(388)	(600)	(1,530)	(1,623)
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on marketable securities	(3)	0	0	0
Foreign currency translation	14	144	384	168
Gain (loss) on cash flow hedges	3	11	(9)	20
Pension and postretirement benefits	0	16	(5)	68
Total other comprehensive income (loss), net of tax	14	171	370	256
Total comprehensive income (loss), net of tax	(374)	(429)	(1,160)	(1,367)
Comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Comprehensive income (loss) attributable to Celanese Corporation	$ (374)	$ (429)	$ (1,160)	$ (1,367)