Debt (Schedule of Cash Tender Offer) (Details)	3 Months Ended		9 Months Ended
Debt (Schedule of Cash Tender Offer) (Details)	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Mar. 21, 2025 USD ($)	Mar. 21, 2025 EUR (€)
Debt Instrument [Line Items]
Refinancing expense	$ 0	$ 0	$ 32,000,000	$ 0
Senior unsecured notes due 2026, interest rate of 5.277%(1)
Debt Instrument [Line Items]
Debt Instrument, Repurchased Face Amount \| €						€ 552,000,000
Debt Instrument Tender Purchase Price Per 1000 Principal Amount \| €						1,026.68
Debt Instrument, Repurchase Amount \| €						€ 567,000,000
Senior unsecured notes due 2027, interest rate of 6.665%(1)
Debt Instrument [Line Items]
Debt Instrument, Repurchased Face Amount					$ 500,000,000
Debt Instrument Tender Purchase Price Per 1000 Principal Amount					1,031.1
Debt Instrument, Repurchase Amount					$ 516,000,000

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.

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+ Details

Celanese Corp 10-Q