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

Carrying amount of the liability for the asset retirement obligation associated with an asset or business acquired.

No definition available.

Name:	ce_AssetRetirementObligationLiabilityForAssetsOrBusinessesAcquired
Namespace Prefix:	ce_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant