Revenues Remaining Performance Obligation Total (Details)	9 Months Ended
Sep. 30, 2020
Revenue , Remaining Performance Obligation Total [Abstract]
Contract With Customer Liability, Noncurrent, Recognition Period	4 years

Contract With Customer Liability, Noncurrent, Recognition Period

No definition available.

Name:	gra_ContractWithCustomerLiabilityNoncurrentRecognitionPeriod
Namespace Prefix:	gra_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration