Debt - Accounts Receivable Purchasing Facility Narrative (Details) - Amended restated receivable purchasing facility - Secured Debt - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2024	Dec. 31, 2023
Line of Credit Facility [Line Items]
Percentage of fair value of sales receivables	100.00%
Transfer of financial assets accounted for as sales, amount derecognized	$ 290	$ 1,400
Proceeds collected on accounts receivable sold under factoring facilities	318	$ 1,300
Trade Receivables Pledged As Collateral	$ 153

Percentage of fair value of sales receivables.

No definition available.

Name:	ce_PercentageOfFairValueOfSalesReceivables
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

Name:	us-gaap_LineOfCreditFacilityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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

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

- Details

Name:	us-gaap_CreditFacilityAxis=ce_AmendedRestatedReceivablePurchasingFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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