Consolidating Guarantor Financial Information (Schedule of Consolidating Balance Sheets) (Details) - USD ($) $ in Millions	Dec. 31, 2018		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current Assets
Cash and cash equivalents	$ 439		$ 576	$ 638	$ 967
Trade receivables - third party and affiliates	1,017		986
Non-trade receivables, net	301		244
Inventories, net	1,046		900
Marketable securities, at fair value	31		32
Other assets	40		54
Total current assets	2,874		2,792
Investments in affiliates	979		976
Property, plant and equipment, net	3,719		3,762
Deferred income taxes	84		366
Other assets	290		338
Goodwill	1,057	[1]	1,003	796
Intangible assets, net	310		301
Total assets	9,313		9,538
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	561		326
Trade payables - third party and affiliates	819		807
Other liabilities	343		354
Income taxes payable	56		72
Total current liabilities	1,779		1,559
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	2,970		3,315
Deferred income taxes	255		211
Uncertain tax positions	158		156
Benefit obligations	564		585
Other liabilities	208		413
Total noncurrent liabilities	4,155		4,680
Total Celanese Corporation stockholders' equity	2,984		2,887	2,588
Noncontrolling interests	395		412
Total equity	3,379		3,299	3,021
Total liabilities and equity	9,313		9,538
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	40		38
Inventories, net	0		0
Marketable securities, at fair value	0		0
Other assets	0		0
Total current assets	40		38
Investments in affiliates	3,503		2,850
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	3,543		2,888
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	544		0
Trade payables - third party and affiliates	13		0
Other liabilities	1		0
Income taxes payable	0		0
Total current liabilities	558		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	1		0
Total noncurrent liabilities	1		0
Total Celanese Corporation stockholders' equity	2,984		2,888
Noncontrolling interests	0		0
Total equity	2,984		2,888
Total liabilities and equity	3,543		2,888
Issuer [Member]
Current Assets
Cash and cash equivalents	0		0	0	0
Trade receivables - third party and affiliates	0		0
Non-trade receivables, net	551		482
Inventories, net	0		0
Marketable securities, at fair value	0		0
Other assets	24		60
Total current assets	575		542
Investments in affiliates	4,820		4,283
Property, plant and equipment, net	0		0
Deferred income taxes	0		6
Other assets	1,658		1,295
Goodwill	0		0
Intangible assets, net	0		0
Total assets	7,053		6,126
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	333		76
Trade payables - third party and affiliates	1		1
Other liabilities	87		71
Income taxes payable	0		0
Total current liabilities	421		148
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	3,104		3,128
Deferred income taxes	15		0
Uncertain tax positions	0		0
Benefit obligations	0		0
Other liabilities	10		0
Total noncurrent liabilities	3,129		3,128
Total Celanese Corporation stockholders' equity	3,503		2,850
Noncontrolling interests	0		0
Total equity	3,503		2,850
Total liabilities and equity	7,053		6,126
Subsidiary Guarantors [Member]
Current Assets
Cash and cash equivalents	30		230	51	21
Trade receivables - third party and affiliates	96		89
Non-trade receivables, net	797		279
Inventories, net	329		277
Marketable securities, at fair value	31		32
Other assets	10		12
Total current assets	1,293		919
Investments in affiliates	4,678		3,916
Property, plant and equipment, net	1,289		1,145
Deferred income taxes	0		206
Other assets	142		171
Goodwill	399		314
Intangible assets, net	132		48
Total assets	7,933		6,719
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	465		148
Trade payables - third party and affiliates	342		300
Other liabilities	267		302
Income taxes payable	475		471
Total current liabilities	1,549		1,221
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	1,679		1,254
Deferred income taxes	85		0
Uncertain tax positions	6		1
Benefit obligations	250		277
Other liabilities	99		255
Total noncurrent liabilities	2,119		1,787
Total Celanese Corporation stockholders' equity	4,265		3,711
Noncontrolling interests	0		0
Total equity	4,265		3,711
Total liabilities and equity	7,933		6,719
Non-Guarantors [Member]
Current Assets
Cash and cash equivalents	409		346	587	946
Trade receivables - third party and affiliates	1,040		988
Non-trade receivables, net	697		385
Inventories, net	765		672
Marketable securities, at fair value	0		0
Other assets	37		93
Total current assets	2,948		2,484
Investments in affiliates	855		861
Property, plant and equipment, net	2,430		2,617
Deferred income taxes	86		158
Other assets	461		165
Goodwill	658		689
Intangible assets, net	178		253
Total assets	7,616		7,227
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	258		369
Trade payables - third party and affiliates	583		598
Other liabilities	258		273
Income taxes payable	88		92
Total current liabilities	1,187		1,332
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	127		233
Deferred income taxes	157		215
Uncertain tax positions	152		157
Benefit obligations	314		308
Other liabilities	138		158
Total noncurrent liabilities	888		1,071
Total Celanese Corporation stockholders' equity	5,146		4,412
Noncontrolling interests	395		412
Total equity	5,541		4,824
Total liabilities and equity	7,616		7,227
Consolidation Eliminations [Member]
Current Assets
Cash and cash equivalents	0		0	$ 0	$ 0
Trade receivables - third party and affiliates	(119)		(91)
Non-trade receivables, net	(1,784)		(940)
Inventories, net	(48)		(49)
Marketable securities, at fair value	0		0
Other assets	(31)		(111)
Total current assets	(1,982)		(1,191)
Investments in affiliates	(12,877)		(10,934)
Property, plant and equipment, net	0		0
Deferred income taxes	(2)		(4)
Other assets	(1,971)		(1,293)
Goodwill	0		0
Intangible assets, net	0		0
Total assets	(16,832)		(13,422)
Current Liabilities
Short-term borrowings and current installments of long-term debt - third party and affiliates	(1,039)		(267)
Trade payables - third party and affiliates	(120)		(92)
Other liabilities	(270)		(292)
Income taxes payable	(507)		(491)
Total current liabilities	(1,936)		(1,142)
Noncurrent Liabilities
Long-term debt, net of unamortized deferred financing costs	(1,940)		(1,300)
Deferred income taxes	(2)		(4)
Uncertain tax positions	0		(2)
Benefit obligations	0		0
Other liabilities	(40)		0
Total noncurrent liabilities	(1,982)		(1,306)
Total Celanese Corporation stockholders' equity	(12,914)		(10,974)
Noncontrolling interests	0		0
Total equity	(12,914)		(10,974)
Total liabilities and equity	$ (16,832)		$ (13,422)

[1] There were $0 million of accumulated impairment losses as of December 31, 2018.