Cover
Cover - USD ($) | 12 Months Ended | ||
Dec. 31, 2020 | Mar. 31, 2021 | Jun. 30, 2020 | |
Cover [Abstract] | |||
Entity Central Index Key | 0001045309 | ||
Amendment Flag | false | ||
Current Fiscal Year End Date | --12-31 | ||
Document Fiscal Year Focus | 2020 | ||
Document Fiscal Period Focus | FY | ||
Document Type | 10-K/A | ||
Document Annual Report | true | ||
Document Period End Date | Dec. 31, 2020 | ||
Document Transition Report | false | ||
Entity File Number | 1-13953 | ||
Entity Registrant Name | W. R. GRACE & CO. | ||
Entity Incorporation, State or Country Code | DE | ||
Entity Tax Identification Number | 65-0773649 | ||
Entity Address, Address Line One | 7500 Grace Drive | ||
Entity Address, City or Town | Columbia | ||
Entity Address, State or Province | MD | ||
Entity Address, Postal Zip Code | 21044-4098 | ||
City Area Code | (410) | ||
Local Phone Number | 531-4000 | ||
Title of 12(b) Security | Common Stock, $0.01 par value per share | ||
Trading Symbol | GRA | ||
Security Exchange Name | NYSE | ||
Entity Well-known Seasoned Issuer | Yes | ||
Entity Voluntary Filers | No | ||
Entity Current Reporting Status | Yes | ||
Entity Interactive Data Current | Yes | ||
Entity Filer Category | Large Accelerated Filer | ||
Entity Small Business | false | ||
Entity Emerging Growth Company | false | ||
ICFR Auditor Attestation Flag | true | ||
Entity Shell Company | false | ||
Entity Public Float | $ 2,844,898,340 | ||
Entity Common Stock, Shares Outstanding | 66,248,119 |