Debt Debt (Accounts Receivable Securitization Facility) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Europe and Singapore Factoring Agreements
Debt Instrument [Line Items]
Transfer of Financial Assets Accounted for as Sales, Amount Derecognized	$ 230	$ 233
Proceeds from Accounts Receivable Securitization	185	237
Singapore Discounting Agreement
Debt Instrument [Line Items]
Transfer of Financial Assets Accounted for as Sales, Amount Derecognized	$ 70
Secured Debt [Member] \| Amended Restated Receivable Securitization Facility [Member]
Debt Instrument [Line Items]
PercentageOfFairValueOfSalesReceivables	100.00%
Transfer of Financial Assets Accounted for as Sales, Amount Derecognized	$ 1,100	595
Trade Receivables Pledged As Collateral	115
Proceeds from Accounts Receivable Securitization	$ 1,100	$ 476

Percentage of fair value of sales receivables.

No definition available.

Name:	ce_PercentageOfFairValueOfSalesReceivables
Namespace Prefix:	ce_
Data Type:	dtr-types:percentItemType
Balance Type:	na
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:	duration

- 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

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Proceeds from securitizations of receivables treated as collateralized borrowings, which are classified as financing transactions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromAccountsReceivableSecuritization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4D
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=SL51823488-111719

+ Details

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

- Details

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

- Details

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

- Details

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

- Details

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