Debt - Accounts Receivable Securitization Facility Narrative (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
Sep. 30, 2023	Dec. 31, 2022
Amended restated receivable securitization facility \| Secured Debt
Line of Credit Facility [Line Items]
Percentage of fair value of sales receivables	100.00%
Secured Debt \| Amended restated receivable securitization facility
Line of Credit Facility [Line Items]
Transfer of financial assets accounted for as sales, amount derecognized	$ 1,000	$ 1,100
Proceeds collected on accounts receivable sold under factoring facilities	977	$ 1,100
Cash flows between transferor and transferee, proceeds from new transfers	$ 110

Percentage of fair value of sales receivables.

No definition available.

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Namespace Prefix:	ce_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Proceeds Collected on Accounts Receivable Sold under Factoring Facilities

+ References

No definition available.

+ Details

Name:	ce_ProceedsCollectedOnAccountsReceivableSoldUnderFactoringFacilities
Namespace Prefix:	ce_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of trade receivables pledged as collateral.

+ References

No definition available.

+ Details

Name:	ce_TradeReceivablesPledgedAsCollateral
Namespace Prefix:	ce_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(f))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Amount of derecognized financial assets from transactions which comprise an initial transfer and an agreement entered into in contemplation of the initial transfer resulting in retention of substantially all of the exposure to the economic return throughout the term of the transaction, at the date of derecognition.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 4D
-Subparagraph (a)
-SubTopic 20
-Topic 860
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481326/860-20-50-4D

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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Namespace Prefix:
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- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
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- Details

Name:	us-gaap_DebtInstrumentAxis=ce_AmendedRestatedReceivableSecuritizationFacilityMember
Namespace Prefix:
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Period Type: