| Document and Entity Information | Sep. 30, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Sep. 30, 2020 |
| Entity Registrant Name | VAALCO Energy, Inc. |
| Entity Central Index Key | 0000894627 |
| Entity Emerging Growth Company | false |
| Title of 12(b) Security | Common Stock, par value $0.10 |
| Trading Symbol | EGY |
| Security Exchange Name | NYSE |
| Entity File Number | 001-32167 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 76-0274813 |
| Entity Address, Address Line One | 9800 Richmond Avenue, Suite 700 |
| Entity Address, City or Town | Houston |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 77042 |
| City Area Code | 713 |
| Local Phone Number | 623-0801 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
