Consolidating Guarantor Financial Information (Schedule of Consolidating Balance Sheets) (Details) - USD ($) $ in Millions	Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current Assets
Cash and cash equivalents	$ 576		$ 638	$ 967	$ 780
Trade receivables - third party and affiliates	986		801
Non-trade receivables, net	244		223
Inventories, net	900		720
Marketable securities, at fair value	32		30
Other assets	54		60
Total current assets	2,792		2,472
Investments in affiliates	976		852
Property, plant and equipment, net	3,762		3,577
Deferred income taxes	366		159
Other assets	338		307
Goodwill	1,003	[1]	796	705
Intangible assets, net	301		194
Total assets	9,538		8,357
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	326		118
Trade payables - third party and affiliates	807		625
Other liabilities	354		322
Deferred income taxes	0		0
Income taxes payable	72		12
Total current liabilities	1,559		1,077
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	3,315		2,890
Deferred income taxes	211		130
Uncertain tax positions	156		131
Benefit obligations	585		893
Other liabilities	413		215
Total noncurrent liabilities	4,680		4,259
Total Celanese Corporation stockholders' equity	2,887		2,588	2,378
Noncontrolling interests	412		433
Total equity	3,299		3,021	2,829
Total liabilities and equity	9,538		8,357
Parent Guarantor [Member]
Current Assets
Cash and cash equivalents	0		0	0	0
Trade receivables - third party and affiliates	0		0
Non-trade receivables, net	38		40
Inventories, net	0		0
Marketable securities, at fair value	0		0
Other assets	0		0
Total current assets	38		40
Investments in affiliates	2,850		2,548
Property, plant and equipment, net	0		0
Deferred income taxes	0		0
Other assets	0		0
Goodwill	0		0
Intangible assets, net	0		0
Total assets	2,888		2,588
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	0		0
Trade payables - third party and affiliates	0		0
Other liabilities	0		0
Deferred income taxes	0		0
Income taxes payable	0		0
Total current liabilities	0		0
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	0		0
Deferred income taxes	0		0
Uncertain tax positions	0		0
Benefit obligations	0		0
Other liabilities	0		0
Total noncurrent liabilities	0		0
Total Celanese Corporation stockholders' equity	2,888		2,588
Noncontrolling interests	0		0
Total equity	2,888		2,588
Total liabilities and equity	2,888		2,588
Issuer [Member]
Current Assets
Cash and cash equivalents	0		0	0	0
Trade receivables - third party and affiliates	0		0
Non-trade receivables, net	482		499
Inventories, net	0		0
Marketable securities, at fair value	0		0
Other assets	60		42
Total current assets	542		541
Investments in affiliates	4,283		4,029
Property, plant and equipment, net	0		0
Deferred income taxes	6		0
Other assets	1,295		705
Goodwill	0		0
Intangible assets, net	0		0
Total assets	6,126		5,275
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	76		6
Trade payables - third party and affiliates	1		0
Other liabilities	71		58
Deferred income taxes	0		0
Income taxes payable	0		0
Total current liabilities	148		64
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	3,128		2,647
Deferred income taxes	0		16
Uncertain tax positions	0		0
Benefit obligations	0		0
Other liabilities	0		0
Total noncurrent liabilities	3,128		2,663
Total Celanese Corporation stockholders' equity	2,850		2,548
Noncontrolling interests	0		0
Total equity	2,850		2,548
Total liabilities and equity	6,126		5,275
Subsidiary Guarantors [Member]
Current Assets
Cash and cash equivalents	230		51	21	110
Trade receivables - third party and affiliates	89		107
Non-trade receivables, net	279		249
Inventories, net	277		239
Marketable securities, at fair value	32		30
Other assets	12		25
Total current assets	919		701
Investments in affiliates	3,916		3,655
Property, plant and equipment, net	1,145		1,049
Deferred income taxes	206		91
Other assets	171		133
Goodwill	314		314
Intangible assets, net	48		48
Total assets	6,719		5,991
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	148		133
Trade payables - third party and affiliates	300		226
Other liabilities	302		167
Deferred income taxes	0		0
Income taxes payable	471		454
Total current liabilities	1,221		980
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	1,254		727
Deferred income taxes	0		0
Uncertain tax positions	1		3
Benefit obligations	277		636
Other liabilities	255		74
Total noncurrent liabilities	1,787		1,440
Total Celanese Corporation stockholders' equity	3,711		3,571
Noncontrolling interests	0		0
Total equity	3,711		3,571
Total liabilities and equity	6,719		5,991
Non-Guarantors [Member]
Current Assets
Cash and cash equivalents	346		587	946	670
Trade receivables - third party and affiliates	988		819
Non-trade receivables, net	385		308
Inventories, net	672		526
Marketable securities, at fair value	0		0
Other assets	93		76
Total current assets	2,484		2,316
Investments in affiliates	861		752
Property, plant and equipment, net	2,617		2,528
Deferred income taxes	158		86
Other assets	165		156
Goodwill	689		482
Intangible assets, net	253		146
Total assets	7,227		6,466
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	369		250
Trade payables - third party and affiliates	598		524
Other liabilities	273		262
Deferred income taxes	0		0
Income taxes payable	92		75
Total current liabilities	1,332		1,111
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	233		210
Deferred income taxes	215		132
Uncertain tax positions	157		130
Benefit obligations	308		257
Other liabilities	158		142
Total noncurrent liabilities	1,071		871
Total Celanese Corporation stockholders' equity	4,412		4,051
Noncontrolling interests	412		433
Total equity	4,824		4,484
Total liabilities and equity	7,227		6,466
Consolidation Eliminations [Member]
Current Assets
Cash and cash equivalents	0		0	$ 0	$ 0
Trade receivables - third party and affiliates	(91)		(125)
Non-trade receivables, net	(940)		(873)
Inventories, net	(49)		(45)
Marketable securities, at fair value	0		0
Other assets	(111)		(83)
Total current assets	(1,191)		(1,126)
Investments in affiliates	(10,934)		(10,132)
Property, plant and equipment, net	0		0
Deferred income taxes	(4)		(18)
Other assets	(1,293)		(687)
Goodwill	0		0
Intangible assets, net	0		0
Total assets	(13,422)		(11,963)
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	(267)		(271)
Trade payables - third party and affiliates	(92)		(125)
Other liabilities	(292)		(165)
Deferred income taxes	0		0
Income taxes payable	(491)		(517)
Total current liabilities	(1,142)		(1,078)
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	(1,300)		(694)
Deferred income taxes	(4)		(18)
Uncertain tax positions	(2)		(2)
Benefit obligations	0		0
Other liabilities	0		(1)
Total noncurrent liabilities	(1,306)		(715)
Total Celanese Corporation stockholders' equity	(10,974)		(10,170)
Noncontrolling interests	0		0
Total equity	(10,974)		(10,170)
Total liabilities and equity	$ (13,422)		$ (11,963)

[1] There were $0 million of accumulated impairment losses as of December 31, 2017.