Consolidating Guarantor Financial Information (Schedule of Consolidating Balance Sheet) (Details) - USD ($) $ in Millions	Jun. 30, 2019		Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Current Assets
Cash and cash equivalents	$ 491		$ 439	$ 708	$ 576
Trade receivables - third party and affiliates	971		1,017
Non-trade receivables, net	332		301
Inventories, net	1,011		1,046
Marketable securities, at fair value	27		31
Other assets	44		40
Total current assets	2,876		2,874
Investments in affiliates	959		979
Property, Plant and Equipment, Net	3,642		3,719
Operating Lease, Right-of-Use Asset	209		0
Deferred income taxes	90		84
Other assets	320		290
Goodwill	1,083	[1]	1,057
Intangible Assets, Net (Excluding Goodwill)	327		310
Total assets	9,506		9,313
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	319		561
Trade payables - third party and affiliates	764		819
Other liabilities	302		343
Income taxes payable	23		56
Total current liabilities	1,408		1,779
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	3,444		2,970
Deferred income taxes	265		255
Uncertain tax positions	171		158
Benefit obligations	545		564
Operating Lease, Liability, Noncurrent	192		0
Other liabilities	227		208
Total noncurrent liabilities	4,844		4,155
Total Celanese Corporation stockholders' equity	2,864		2,984	3,380
Noncontrolling interests	390		395
Total equity	3,254		3,379	3,787
Total liabilities and equity	9,506		9,313
Parent Guarantor [Member]
Current Assets
Cash and cash equivalents	0		0	2	0
Trade receivables - third party and affiliates	0		0
Non-trade receivables, net	40		40
Inventories, net	0		0
Marketable securities, at fair value	0		0
Other assets	0		0
Total current assets	40		40
Investments in affiliates	3,760		3,503
Property, Plant and Equipment, Net	0		0
Operating Lease, Right-of-Use Asset	0
Deferred income taxes	0		0
Other assets	0		0
Goodwill	0		0
Intangible Assets, Net (Excluding Goodwill)	0		0
Total assets	3,800		3,543
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	910		544
Trade payables - third party and affiliates	25		13
Other liabilities	0		1
Income taxes payable	0		0
Total current liabilities	935		558
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	0		0
Deferred income taxes	0		0
Uncertain tax positions	1		0
Benefit obligations	0		0
Operating Lease, Liability, Noncurrent	0
Other liabilities	0		1
Total noncurrent liabilities	1		1
Total Celanese Corporation stockholders' equity	2,864		2,984
Noncontrolling interests	0		0
Total equity	2,864		2,984
Total liabilities and equity	3,800		3,543
Issuer [Member]
Current Assets
Cash and cash equivalents	0		0	0	0
Trade receivables - third party and affiliates	0		0
Non-trade receivables, net	1,025		551
Inventories, net	0		0
Marketable securities, at fair value	0		0
Other assets	28		24
Total current assets	1,053		575
Investments in affiliates	4,937		4,820
Property, Plant and Equipment, Net	0		0
Operating Lease, Right-of-Use Asset	0
Deferred income taxes	0		0
Other assets	1,658		1,658
Goodwill	0		0
Intangible Assets, Net (Excluding Goodwill)	0		0
Total assets	7,648		7,053
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	197		333
Trade payables - third party and affiliates	1		1
Other liabilities	41		87
Income taxes payable	0		0
Total current liabilities	239		421
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	3,590		3,104
Deferred income taxes	15		15
Uncertain tax positions	2		0
Benefit obligations	0		0
Operating Lease, Liability, Noncurrent	0
Other liabilities	42		10
Total noncurrent liabilities	3,649		3,129
Total Celanese Corporation stockholders' equity	3,760		3,503
Noncontrolling interests	0		0
Total equity	3,760		3,503
Total liabilities and equity	7,648		7,053
Subsidiary Guarantors [Member]
Current Assets
Cash and cash equivalents	51		30	93	230
Trade receivables - third party and affiliates	100		96
Non-trade receivables, net	1,631		797
Inventories, net	327		329
Marketable securities, at fair value	27		31
Other assets	23		10
Total current assets	2,159		1,293
Investments in affiliates	4,126		4,678
Property, Plant and Equipment, Net	1,349		1,289
Operating Lease, Right-of-Use Asset	55
Deferred income taxes	0		0
Other assets	176		142
Goodwill	399		399
Intangible Assets, Net (Excluding Goodwill)	129		132
Total assets	8,393		7,933
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	819		465
Trade payables - third party and affiliates	270		342
Other liabilities	151		267
Income taxes payable	500		475
Total current liabilities	1,740		1,549
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	1,678		1,679
Deferred income taxes	85		85
Uncertain tax positions	5		6
Benefit obligations	242		250
Operating Lease, Liability, Noncurrent	44
Other liabilities	98		99
Total noncurrent liabilities	2,152		2,119
Total Celanese Corporation stockholders' equity	4,501		4,265
Noncontrolling interests	0		0
Total equity	4,501		4,265
Total liabilities and equity	8,393		7,933
Non-Guarantors [Member]
Current Assets
Cash and cash equivalents	440		409	613	346
Trade receivables - third party and affiliates	991		1,040
Non-trade receivables, net	611		697
Inventories, net	739		765
Marketable securities, at fair value	0		0
Other assets	39		37
Total current assets	2,820		2,948
Investments in affiliates	832		855
Property, Plant and Equipment, Net	2,293		2,430
Operating Lease, Right-of-Use Asset	154
Deferred income taxes	92		86
Other assets	452		461
Goodwill	684		658
Intangible Assets, Net (Excluding Goodwill)	198		178
Total assets	7,525		7,616
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	752		258
Trade payables - third party and affiliates	588		583
Other liabilities	268		258
Income taxes payable	28		88
Total current liabilities	1,636		1,187
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	114		127
Deferred income taxes	167		157
Uncertain tax positions	163		152
Benefit obligations	303		314
Operating Lease, Liability, Noncurrent	148
Other liabilities	125		138
Total noncurrent liabilities	1,020		888
Total Celanese Corporation stockholders' equity	4,479		5,146
Noncontrolling interests	390		395
Total equity	4,869		5,541
Total liabilities and equity	7,525		7,616
Eliminations [Member]
Current Assets
Cash and cash equivalents	0		0	$ 0	$ 0
Trade receivables - third party and affiliates	(120)		(119)
Non-trade receivables, net	(2,975)		(1,784)
Inventories, net	(55)		(48)
Marketable securities, at fair value	0		0
Other assets	(46)		(31)
Total current assets	(3,196)		(1,982)
Investments in affiliates	(12,696)		(12,877)
Property, Plant and Equipment, Net	0		0
Operating Lease, Right-of-Use Asset	0
Deferred income taxes	(2)		(2)
Other assets	(1,966)		(1,971)
Goodwill	0		0
Intangible Assets, Net (Excluding Goodwill)	0		0
Total assets	(17,860)		(16,832)
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	(2,359)		(1,039)
Trade payables - third party and affiliates	(120)		(120)
Other liabilities	(158)		(270)
Income taxes payable	(505)		(507)
Total current liabilities	(3,142)		(1,936)
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	(1,938)		(1,940)
Deferred income taxes	(2)		(2)
Uncertain tax positions	0		0
Benefit obligations	0		0
Operating Lease, Liability, Noncurrent	0
Other liabilities	(38)		(40)
Total noncurrent liabilities	(1,978)		(1,982)
Total Celanese Corporation stockholders' equity	(12,740)		(12,914)
Noncontrolling interests	0		0
Total equity	(12,740)		(12,914)
Total liabilities and equity	$ (17,860)		$ (16,832)

[1] There were $0 million of accumulated impairment losses as of June 30, 2019.