Asbestos-Related Litigation	9 Months Ended
Sep. 30, 2012
Asbestos-Related Litigation
Asbestos-Related Litigation	3. Asbestos-Related Litigation

This element represents the history of asbestos-related litigation, disclosure of provisions for asbestos-related contingencies and changes since date of bankruptcy filing, and disclosure of asbestos-related insurance coverage, including rights to receive insurance recoveries related to asbestos-related claims.

No definition available.

Name:	gra_AsbestosRelatedLitigationDisclosureTextBlock
Namespace Prefix:	gra_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration