| Document and Entity Information | Nov. 18, 2021 |
| Cover [Abstract] | |
| Entity Registrant Name | VALERO ENERGY CORP/TX |
| Amendment Flag | false |
| Entity Central Index Key | 0001035002 |
| Document Type | 8-K |
| Document Period End Date | Nov. 18, 2021 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-13175 |
| Entity Tax Identification Number | 74-1828067 |
| Entity Address, Address Line One | One Valero Way |
| Entity Address, City or Town | San Antonio |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 78249 |
| City Area Code | (210) |
| Local Phone Number | 345-2000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common stock |
| Trading Symbol | VLO |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
