Asbestos-Related Litigation (Tables)	9 Months Ended
Sep. 30, 2012
Asbestos-Related Litigation
Schedule of range of the asbestos-related liabilities	Table 1

Tabular disclosure of valuation range of the asbestos-related liabilities, used as basis for reasonable estimate of recorded amount of the asbestos-related liabilities.

No definition available.

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