Noncurrent Other Liabilities (Schedule of Changes in Asset Retirement Obligations Narrative) (Details) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Other Liabilities, Noncurrent [Abstract]
Asset retirement obligation, liability for assets or businesses acquired	$ 10	$ 10
Asset retirement obligation, recoveries long-term receivable noncurrent other assets	$ 10

Carrying amount as of the balance sheet date of known and reasonably estimable amounts of recoveries from third-parties pertaining to asset retirement obligations associated with assets or businesses acquired.

No definition available.

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